chp-r report damhead creek 2 power station · 2016-02-29 · a chp system generates electricity...

CHP-R REPORT

DAMHEAD CREEK 2 POWER STATION

Name Job Title Signature Date

Prepared Luke Aldred Senior Energy

Engineer

2 February

2016

Checked Oliver Riley Technical Director,

AECOM

2 February

2016

Technical Review

Oliver Riley Technical Director,

AECOM

2 February

2016

AMENDMENT RECORD

Issue Date Issued Date Effective Purpose of Issue and Description of Amendment

0 8 December 2015 8 December 2015 S36 Variation Draft for Comment

1 7 January 2016 7 January 2016 S36 Variation Draft for Issue

2 2 February 2016 2 February 2016 S36 Variation Final for Submission

TABLE OF CONTENTS

1. Introduction ............................................................................................................. 1

1.1 Principles of Combined Heat and Power and District Heating ........................................................... 1

2. Description of the Proposed Development ............................................................. 2

2.1 Plant Location ..................................................................................................................................... 2

2.2 Plant Description ................................................................................................................................ 2

3. Policy Context ......................................................................................................... 4

3.1 Overarching National Policy Statement for Energy EN-1 (NPS EN-1)............................................... 4

3.2 National Policy Statement for Fossil Fuel Generation EN-2 (NPS EN-2) .......................................... 5

3.3 Guidance on background information to accompany notifications under Section 14 (1) of the

Energy Act (1976) and applications under Section 36 of the Electricity Act (1989) ........................... 5

3.4 Environment Agency, CHP Ready Guidance for Combustion and Energy from Waste Power Plants6

3.5 National Planning Policy Framework (NPPF) ..................................................................................... 6

3.6 Department for Environment, Food & Rural Affairs, Transposition in England and Wales of Articles

14(5)-(8) of the Energy Efficiency Directive (2012/27/EU) – Consultation ......................................... 7

3.7 Kent Environmental Strategy .............................................................................................................. 7

3.8 Medway Local Plan 2003-2014 .......................................................................................................... 7

4. Objectives and Approach ........................................................................................ 9

5. Potential Heat Loads Assessment ........................................................................ 10

5.1 Overview ........................................................................................................................................... 10

5.2 Current Heat Loads .......................................................................................................................... 10

5.2.1 The National Heat Map .......................................................................... 10

5.2.2 UK CHP Development Map .................................................................... 13

5.3 Future Heat Loads ............................................................................................................................ 17

5.3.1 Lodge Hill (also known as Chattenden Scheme) .................................... 17

5.3.2 Goodman International ........................................................................... 18

5.3.3 National Grid Site ................................................................................... 18

5.4 Ranking of CHP Opportunities in the Area ....................................................................................... 18

5.5 Summary of Potential Heat Users and CHP Opportunities .............................................................. 21

5.5.1 Current Opportunities ............................................................................. 21

DHC2 CHP Readiness Report 4-Feb-16

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5.5.2 Future Opportunities ............................................................................... 22

6. CHP Assessment.................................................................................................. 23

6.1 Plant Operation ................................................................................................................................. 23

6.2 CHP Envelope .................................................................................................................................. 23

6.3 CHP-R Proposal ............................................................................................................................... 23

6.4 Good Quality CHP ............................................................................................................................ 24

7. Technical and Commercial Considerations .......................................................... 25

7.1 District Heating Network Considerations .......................................................................................... 25

7.2 Heat Supply Considerations ............................................................................................................. 25

7.2.1 System Resilience .................................................................................. 25

7.2.2 Absorption Cooling ................................................................................. 25

7.3 Commercial Considerations ............................................................................................................. 25

7.3.1 Heat Price and Connection Charge ........................................................ 25

7.3.2 Heat Supply Agreements ........................................................................ 26

7.3.3 Number of Consumers ........................................................................... 26

8. Conclusions .......................................................................................................... 27

Figures: Figure 5-1: National Heat Map heat density

Figure 5-2: UK CHP Development Map

Figure 5-3: Demand by sector and large heat customers, 15km radius (highlighted)

Tables: Table 2-1: Summary Plant Operation

Table 2-2: Component Dimensions

Table 5-1: Heat load potential

Table 5-2: Description of ranking criteria

Table 5-3: Ranking of potential heat loads

Appendices: Appendix A: Site Location

Appendix B: CHP-R Assessment Form

Appendix C: Plant Layout


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Appendix D: List of Organisations Consulted


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1. Introduction AECOM has undertaken a Combined Heat and Power (CHP) - Readiness Assessment for the proposed Damhead Creek 2 (DHC2) power station (hereafter referred to as the Proposed Development).

On 25 January 2011, ScottishPower secured consent under Section 36 of the Electricity Act 1989, for the development, construction and operation of a new 1,000 MW Combined Cycle Gas Turbine (CCGT) adjacent to the existing Damhead Creek Power Station. Further to this, on 28 July 2014 ScottishPower secured consent under Section 36(c) of the Electricity Act 1989 to increase the output of Damhead Creek 2 CCGT to 1,200 MW (12.04.09.04/265C) and subsequently in October 2015 this was further increased to 1,800 MW output CCGT. ScottishPower (DCL) Ltd now seek to further vary the existing consent to allow flexibility in the make-up of the plant to include up to 300 MW of Open Cycle Gas Turbine (OCGT) peaking plant. The proposed development therefore now comprises a CCGT/OCGT power station with combined electrical capacity up to 1,800 MW, hereafter referred to as the 1,800 MW CCGT with peaking plant scheme option, although the application to vary the consent retains the option of constructing the already consented 1,800 MW CCGT only, scheme as well. As the CHP potential of the CCGT-only scheme was assessed as part of that 2015 variation application, this assessment focuses on the new variant that potentially includes peaking plant.

This CHP Readiness study is intended to evaluate the feasibility of supplying the heat that is generated during the electrical generation process to nearby heat customers. Key to this study is the evaluation of the demand for heat in the local area.

This document has been produced in accordance with the requirements of the National Policy Statements (NPSs) EN-1, EN-2, and the Environmental Agency’s (EA’S) CHP Ready Guidance 2013, as well as the national and regional planning policies, in order to assess the Proposed Development against the CHP-Readiness requirements and demonstrate compliance.

1.1 Principles of Combined Heat and Power and District Heating A CHP system generates electricity while also providing useable heat from the same process. The useable heat can be recovered from parts of the electricity generating process, such as the cooling or flue systems, where it may otherwise be lost to the environment. This can provide a more efficient energy generation system compared to traditional power-only CCGT generation systems, with the potential to improve typical gross efficiencies of modern plants from 55-61% to in the region of 75-80%.

For a CHP system to be viable, appropriate heat consumers in suitable proximity to the heat source are required. Heat consumers could be in the form of a single user, which at this scale would typically be a large industrial process user, or a number of smaller consumers forming part of a district heating (DH) system.

DH systems comprise a network of pre-insulated pipes carrying hot water or steam from one or more centralised heat generating sources to a number of consumers. The hot water or steam is then typically used for process uses, space heating or domestic hot water (DHW) generation, depending on the requirements of the consumer. DH systems can deliver benefits to consumers by providing a low carbon source of heat in a more efficient manner than may be achievable through single buildings adopting individual measures, as well as reducing the plant and space requirements on-site, which in turn can provide capital and on-going maintenance and energy cost savings. They also provide futureproofing and resilience, as the scale permits alternative heat technologies or fuel streams to be deployed which may not be viable at the building-by-building scale.


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2. Description of the Proposed Development

2.1 Plant Location DHC2 will constitute Phase 2 of the Damhead Creek Power Generation Development on the Hoo Peninsula, Kent, and will be located on land immediately adjacent to the existing operational Damhead Creek CCGT Power Station (see Appendix A). The Site is located approximately 5km northeast of Gillingham and 15km east of Gravesend in north Kent.

The factors that influenced the selection of the plant location are:

• Increasing generation capacity of existing power station site;

• Availability of sufficient land;

• Current land use (the Proposed Development will be built on undeveloped land adjacent to the existing DHC1 site, on the existing power station site);

• Compatibility with relevant Local Plans, i.e. the Proposed Development is aligned with Medway Local Plan;

• Proximity to suitable utilities and grid export connections (availability of 400 kV National Grid transmission system, natural gas and transport infrastructure to accommodate construction traffic);

• Suitability for Carbon Capture and Storage Readiness (CCR).

2.2 Plant Description The power station will comprise a CCGT plant of up to 1,800 MW, or potentially a CCGT and an OCGT peaking plant located on the same Development Site; the peaking plant would have an electrical output capacity of up to 300 MW, but the combined electrical output from the CCGT and OCGT will not exceed the 1,800 MW capacity. In the combined cycle plant, dedicated heat recovery steam generators (HRSG) for each unit will be used to recover waste heat from each gas turbine. The high pressure steam will be used to drive a steam turbine to generate additional electricity. The spent steam leaving the steam turbine equipment will be condensed (via air cooler condensers) and the resultant condensate returned to the HRSGs for re-use.

The steam turbine system will comprise the turbine equipment itself, a multi-cell air cooler condenser and condensate extraction pumps and air extraction equipment.

Each gas turbine will comprise an inlet air filter, an air compressor, combustion chamber, power turbine and exhaust silencer. The combustion system will be a dry low-NOx (DLN) system, which limits emissions of NOx to the atmosphere.

The flue gases from each CCGT module will be discharged to a dedicated stack after passing through the HRSG.

The combined cycle plant will achieve overall electrical generation efficiency, when operating at full capacity, of approximately 60% based on the lower calorific value (LCV) of the fuel and around 54% electrical generation efficiency based on the higher calorific value (HCV) of the fuel. Table 2-1 shows a summary of the plant operation.

The peaking plant of up to 300 MW capacity will operate in OCGT mode and without any steam system. Correspondingly the electrical efficiency of the units will be lower – around 34%, as there is no heat recovery at the outlet of the gas turbines. This is because the peaking plant needs to operate in a fast response mode to be able to ramp up to meet any shortfall in generation on the UK grid as quickly as possible, and open cycle units can achieve full output in around 45 minutes (warm start-up) as opposed to around 96 minutes for a CCGT.


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Table 2-1: Summary Plant Operation for CCGT (2 units)

Maximum Load Minimum Load

Thermal input (LHV) 2501 1445

Thermal input (HHV) 2774 1603

Electrical output 1,504 794

Electrical efficiency (LHV) 60% 55%

Electrical efficiency (HHV) 54% 50%

The electricity generated will be exported to the National Grid via the existing Kingsnorth substation lying to the south west of the existing Damhead Creek CCGT Power Station. Table 2-2 shows dimensions of the components subject to the Variation Application and shows a multi-shaft arrangement, as a potential CCGT configuration.

Table 2-2: Component Dimensions (illustrative)

Structure No. plant/buildings Dimensions (m) Height (m)

Gas turbine building 2 72x31 30

Steam turbine building 1 60x30 25

HRSG building 1 36x34 45

Peaking plant GT building 2 84x30 20

HRSG stack 2 - 95

Peaking plant stack 2 - 50

Air cooled condenser 60 84x135 46.5

Peaking plant fin fan coolers 4 set of fans 12x11 7

CCGT fin fan coolers 1 41x22 8

Transformer 3 22x15 3

The exact dimensions for the proposed 1,800 MW CCGT with peaking plant scheme option and building requirements will be confirmed at the detailed design stage and will be agreed with Medway Council, prior to the commencement of construction. The above dimensions however represent the likely sizes of the main components based on ScottishPower (DCL) Ltd’s discussions with the Original Equipment Manufacturers.

The Proposed Development will be able to operate 24 hours a day, 365 days a year. However due to the predicted market demand, it is anticipated that the CCGTs will operate at an average load across its lifetime that is potentially much lower than the maximum design duty; future load factors could be as low as 60%. Similarly, the peaking plant is only expected to operate for up to 1,500 hours per year to respond to peak demand on the UK transmission system. The power generation from DHC2 will therefore be both irregular and intermittent. It is also recognised that the loading of the plant will be market driven and will depend on factors outside the control on the plant, including the future path of energy demand and the national generating capacity.


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3. Policy Context On 25 January 2011, ScottishPower secured consent under Section 36 of the Electricity Act 1989, for the development, construction and operation of a new 1,000 MW CCGT adjacent to the existing Damhead Creek Power Station (DHC1). Subsequently, on 28 July 2014 ScottishPower secured consent under Section 36(c) of the Electricity Act 1989 to increase the output of DHC2 CCGT to 1,200 MW (12.04.09.04/265C). Further consent has since been granted in October 2015 to increase the capacity of DHC2 to 1,800 MW. ScottishPower (DCL) Ltd is applying for a variation to the existing Section 36 consent to allow flexibility in operation through a combination of CCGT units and up to 300 MW of OCGT units (to be operated as peaking plant). The Planning Act 20081 defines the Proposed Development as a ‘nationally significant infrastructure project’ (NSIP), as it is an onshore electrical generating station with more than 50 MW capacity. Consent for this development was secured under the previous (section 36) consenting regime, therefore this variation is also under the previous regime.

Policies for NSIPs are set out in the National Policy Statements (NPS). Whilst this application is under the previous regime, these statements clearly set out current national energy policy which is of relevance to the proposed development. Those that are relevant to the Proposed Development and this CHP assessment are described in the following sections.

3.1 Overarching National Policy Statement for Energy EN-1 (NPS EN-1) Section 4.6 of the NPS EN-1 highlights considerations for CHP and describes the government’s commitment to reducing carbon dioxide (CO2) emissions through the promotion of good quality CHP and outlines the assessment criteria. In particular, it:

1. Describes CHP as “Combined Heat and Power (CHP), which is the generation of usable heat and electricity in a single process. A CHP station may either supply steam direct to customers or capture waste heat for low-pressure steam, hot water or space heating purposes after it has been used to drive electricity generating turbines. The heat can also be used to drive absorption chillers, thereby providing cooling.”

2. Highlights that heat generated by CHP can substantially reduce the amount of fuel consumed that would otherwise be wasted. Although there are other methods for thermal generation, natural gas-fired is considered the most viable option within the policy statement.

3. Denotes the benefits of CHP being a less CO2 intensive method of heating and electricity generation. This is because the technology uses less fuel to produce the same amount of heat and power than conventional methods. In order to be eligible for the government support, associated with the CHP Quality Assurance programme, in accordance with the EU Cogeneration Directive, schemes need to achieve at least 10% primary energy savings.

4. Emphases that according to Department for Environment, Food and Rural Affairs (DEFRA), in 2009, there was a total of 5.6 gigawatts (GW) of ‘Good Quality’ CHP in the UK, providing over 7% of electricity and saving an estimated 9.5 megatonnes of carbon dioxide (MTCO2) per annum. DEFRA believes that, potentially, there is cost-effective development for a further 10 GW of ‘Good Quality’ CHP, estimated to offer a further saving of 175 MTCO2 by 2015.

5. States that in order for CHP to be considered as economically viable the plant needs to be closely located to consumers with heat demands, though this distance will vary with the nature of the demand. An example of a cost-effective distance from a Department of Energy and Climate Change (DECC) report on district heating networks2 is given as 200 megawatts thermal (MWth) of heat within 15 kilometres (km).

6. Denotes that consent Applications must either include CHP or contain evidence that the possibilities have been fully explored.

7. Refers to liaising with potential heat consumers if identified.

2 The Potential and Costs of District Heating Networks, Pöyry and Faber Maunsell, April 2009


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8. Explains that, where the proposal is for thermal generation without CHP, the applicant should:

• Explain why CHP is not economically or practically feasible;

• Provide details of any potential future heat demands in the area; and

• Detail provisions in the proposed scheme for exploiting any potential heat demand in the future.

9. States that as some CHP systems require more plant room space than non-CHP generating systems. Applicants must show and explain how current and / or planned CHP systems will be integrated into the proposed site and be Carbon Capture ‘ready’.

3.2 National Policy Statement for Fossil Fuel Generation EN-2 (NPS EN-2) CHP considerations and guidelines are described in Section 2.3 of NPS EN-2. These are to be considered in conjunction with those outlined in NPS EN-1 and the guidance document created by the former Department of Trade and Industry (DTI) on Background Information to Accompany Notifications Under Section 14(1) of the Energy Act 1976 and Applications under Section 36 of the Electricity Act 1989 (December 2006).

Paragraph 2.2.4 of this NPS states that sufficient space must be allocated for CHP systems and relates to EN-1 (Section 5.10).

Paragraphs 2.3.2 and 2.3.3 state that all CHP options need to be fully explored and applicants must include considerations and show evidence in conjunction with EN-1 (Section 4.6). Where there is reason to believe that future opportunities for CHP may arise, if a non-CHP solution is proposed, then developers are required to ensure that the station is ‘CHP ready’ to allow heat supply at a later date. All applicants must demonstrate that CHP has been considered and the IPC (now the Planning Inspectorate) should not give development consent until it is satisfied sufficient evidence has been provided (EN-1 Section 4.6.8). It is assumed that DECC, as regulators of the previous regime, follow the same approach for variations under the previous regime.

3.3 Guidance on background information to accompany notifications under Section 14 (1) of the Energy Act (1976) and applications under Section 36 of the Electricity Act (1989)3

The former DTI provides guidance for new power stations and electricity and heat generation. On 15 December 2006, the DTI issued guidance to power station developers to maximise the use of CHP where feasible. In issuing this guidance the Government signalled its strong commitment to CHP, whilst recognising that it is up to the market to bring forward the most competitive proposals to help ensure security of supply.

Paragraph 11 provides details of the evidence and steps that need to be taken by the applicant in order to assess the viability of CHP. These include:

• An explanation of their choice of location, including the potential viability of the site for CHP;

• A report on the exploration carried out to identify and consider the economic feasibility of local heat opportunities and how to maximise the benefits from CHP;

• The results of the exploration; and

• A list of the organisations contacted.

Paragraph 12 of the Guidance lists what must be included with applications where CHP is not to be included. This includes:

• The basis for the developer’s conclusion that it is not economically feasible to exploit existing regional heat markets;

• A description of potential future heat requirements in the area; and 3 December 2006


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• The provisions in the proposed scheme for exploiting any potential heat demand in the future.

Paragraph 14 identifies some of the largest and likely most economically viable prospective consumers to be considered. These are as follows:

• Industrial sectors;

• Commerce, including;

o Hotels

o Leisure centres

o Large public buildings

• Public services, including;

o Hospitals

o Universities

o Prisons

o Defence installations

3.4 Environment Agency, CHP Ready Guidance for Combustion and Energy from Waste Power Plants

The Environment Agency (EA) has published, in February 2013, detailed guidance on CHP Readiness Assessments as part of the Environmental Permitting regime. The EA requires applications for Environmental Permits to demonstrate the use of Best Available Techniques (BAT) for a number of criteria, including energy efficiency. One of the principal ways of improving energy efficiency is through the use of CHP. The EA therefore requires developers to satisfy three BAT tests in relation to CHP. The first involves considering and identifying opportunities for the use of heat off-site. Where this is not technically or economically possible and there are no immediate opportunities, the second test involves ensuring that the plant is built to be ‘CHP ready’. The third test involves carrying out periodic reviews to see if the situation has changed and there are opportunities for heat use off site.

The EA guidance reiterates the need for applications for Development Consent involving generating stations to be supported CHP Assessment in line with Section 4.6 of EN-1.

Where Development Consent is granted for a new plant without CHP, the subsequent application for an Environmental Permit should build on the conclusions of the CHP Assessment and contain sufficient information to demonstrate the new plant will be built ‘CHP ready’ (for the chosen location and design).

Additionally, whilst CHP Assessments may only require waste heat to be made available, being CHP-R may require both process heat and waste heat to be made available according to the likely future CHP opportunities identified.

3.5 National Planning Policy Framework (NPPF) The National Planning Policy Framework released in 2012 provides guidelines for the development of Local Planning Authority plans. The following provides details of those aspects relevant to CHP, decentralised energy and district heating.

Section 10 of the NPPF describes how opportunities should be identified for developments to supply heat from decentralised, renewable or low carbon energy sources.

Section 15.6 of the NPPF specifies that Local Plans should set strategic priorities to deliver provisions for infrastructure, including energy and heat.


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3.6 Department for Environment, Food & Rural Affairs, Transposition in England and Wales of Articles 14(5)-(8) of the Energy Efficiency Directive (2012/27/EU) – Consultation

Defra has recently concluded a consultation process on the transposition of Articles 14(5)-(8) of the EU’s Energy Efficiency Directive EED – (2012/27/EU) which was adopted as a Directive in October 2012. The results of the consultation process were published in February 2014.

In summary:

The overall objective of Article 14 is to encourage the identification of cost-effective potential for delivering energy efficiency, through the use of cogeneration, efficient district heating and cooling and the recovery of industrial waste heat or, when these are not cost-effective, through other efficient heating and cooling supply options, and the delivery of this potential.

The objective of Articles 14(5)-(8) is to promote efficiency in heating and cooling by requiring developers of certain installations (above a specified size in terms of thermal input) to consider the opportunities for developing the scheme as co-generation, recovering waste heat and supplying heat to district heating and cooling networks.

3.7 Kent Environmental Strategy The Kent Environmental Strategy (July 2011) outlines the challenges and policies aimed at improving the environmental performance of the county. The Strategy addresses three themes: ecological footprint; climate change; and valuing the natural environment. The priorities relevant to the current assessment being undertaken for the Proposed Development fall under the climate change (CC) theme, and are summarised below:

• CC5: Reduce future carbon emissions:

a) Action CC5.1: Pilot the development of a ‘Low Carbon Framework for Kent’ where the Kent Forum leads by example by cutting emissions from its buildings, activities and services

b) Action CC5.3: Develop a Kent-wide strategy and support programme to implement the recommendations of the Kent County Council Renewable Energy Select Committee.

• CC7: Support the development of green jobs and business in Kent

a) Action CC7.1: Build on the success of the offshore wind prospectus, by developing ‘Kent prospectuses’ outlining the opportunities and support available for key low carbon business sectors that want to locate in Kent, such as biomass.

b) Action CC7.2: Establish a single conversation with low carbon businesses in Kent, especially those related to renewable energy, and with businesses wishing to locate in Kent to take advantage of new green opportunities and create green jobs.

As part of an increased focus on the key sectors of Kent’s economy, the Council are looking at the opportunities for low carbon growth, so that it can focus on the areas with the most potential. Kent’s investment in transition and in developing low carbon opportunities for growth will focus on the largest sources of carbon emissions – energy, transport and housing – through its integrated transport, housing and low carbon sector strategies.

The policies and actions within the Kent Environmental Strategy do not directly relate to or impose requirements on the Proposed Development. However, they set the background for the Proposed Development.

3.8 Medway Local Plan 2003-2014 The Local Development Scheme (LDS) (June 2014) provides an updated programme for the production of a new local plan that will provide the basis for development policy in Medway. The scheme covers the period from 2014 to 2017, and updates the Medway LDS published in August 2011. However, some Medway Local Plan (2003) policies have been retained and will continue to be considered as robust and up-to-date policies within Medway LDS.


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The relevant Policy in the Medway Plan is Policy BNE4 Energy Efficiency, which states that Energy efficiency measures will be sought within development proposals, providing there is no detrimental impact on amenity.

The Medway Plan identifies the Proposed Development’s site as an existing employment area and the site adjacent as a proposed employment area.


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4. Objectives and Approach Based on the policy context described in Section 3, the following scope was developed:

• To identify and assess the magnitude of the industrial and other significant heat demands which are within the vicinity of the Proposed Development;

• To comment on the feasibility of connection to heat users identified above;

• Where viable connections are identified provide a list of the relevant organisations contacted;

• To assess the CHP implications of heat demand uptake scenarios; and

• Outline the provisions made for exploiting any potential heat demands in the future including a CHP-R Assessment where immediate heat loads are not found to be viable.

The findings of this assessment are presented in Sections 5 – 8.

A CHP-R Assessment Form, reflecting the recommended status of the assessment, is included in Appendix B – CHP-R Assessment Form.


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5. Potential Heat Loads Assessment 5.1 Overview A key consideration for the assessing the viability of exporting heat from the site is the demand for heat in the local vicinity. A number of approaches have been adopted to assess the local heat demand, including analysis of the current heat load environment (through the use of the National Heat Map and the UK CHP Development Map), and a local search for future potential heat demands of large scale businesses, industries and residential developments. The results of this analysis are presented in this section.

5.2 Current Heat Loads The current heat load environment within the area has been determined by investigation using the National Heat Map and the UK CHP Development map.

5.2.1 The National Heat Map

The National Heat Map4 has been designed by The Centre for Sustainable Energy and commissioned by DECC. This tool can be used to search for potential viable heat loads for CHP and district heating applications in support of planning and deployment of local sustainable projects in England.

The viability of a heat connection is dependent on the size and predictability of the heat load and its proximity to the source of heat. As outlined in the EN-1 guidance and the scope presented in Section 4, a search area with a radius of 15km from the Proposed Development has been used to identify very large heat loads.

The Proposed Development is located on the Hoo Peninsula, with rivers and sea surrounding three sides; the River Medway lies immediately to the south and east of DHC2, while to the north and east lies the Thames estuary. These natural barriers significantly limit the range of potentially viable heat network infrastructure.

The analysis has considered the locations of the various heat loads in relation to the Thames Estuary and the River Medway. This is done primarily to distinguish between those loads which are readily accessible (without crossing these major rivers) and those that are not readily accessible (which would require crossing these major rivers in order to reach them).

Crossing rivers can be done by one of two ways: over-bridging or tunnelling. Over-bridging is where pipework (which is normally laid in a trench and buried) is directed out of the ground and across the waterway before being re-directed into a buried trench on the other side. This approach has the benefit of keeping pipework infrastructure costs down. However, there are significant issues associated with this approach, including guaranteeing access beneath the pipework for waterway traffic, sight issues, permit risks, and ensuring reliable access arrangements for maintenance. These issues make over-bridging of pipework unacceptable for major waterways such as the Thames Estuary and the River Medway.

Tunnelling beneath a waterway eases some of the difficulties associated with over-bridging, including guaranteeing access for waterway traffic and sight issues. However there are still major difficulties associated with ensuring reliable access arrangements for maintenance. Furthermore, the costs associated with tunnelling beneath large waterways are significant, with costs over £5,000/m recorded for previous experience with similar schemes (compared to £750-1,000/m for conventional trenching costs5). Crossing the Thames Estuary (circa 2km tunnelling required) in this way could cost around £10 million, while for the River Medway (circa 500m tunnelling required) would likely cost in the region of £2-5 million depending on the point of crossing selected. The financial costs associated with laying heat pipework through tunnelling are therefore considered to be too great to make crossing significant

4 http://tools.decc.gov.uk/en/content/cms/heatmap/about_map/about_map.aspx 5 Trenching cost of pre-insulated pipework inclusive of hard dig civil costs in the South-East based on a

contractor’s pricing structure


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waterways such as the Thames Estuary and the River Medway viable, unless doing so makes a very large and dense heat load available for connection.

It is noted that there are many other small waterways in the region, owing to the low-lying landscape on the Hoo Peninsular. Whilst there will be challenges associated with crossing these waterways, doing so is considered much more viable than crossing the Thames Estuary or the River Medway, due to their much smaller scale and their lesser importance in terms of water transport.

The National Heat Map results for the area are shown in Figure 5-1.


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Figure 5-1 – National Heat Map heat density


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The heat demand density distribution shown in Figure 5-1 is not considered to be optimal for the potential of supplying heat from the Proposed Development. The level of potential for heat supply can be categorised as follows.

Table 5-1 – Heat load potential

Category Heat consumption (kWh/m2.yr)

High potential > 100

Medium potential 50 – 100

Low potential < 50

The heat map in Figure 5-1 indicates that the largest heat load in the 15km search radius is the town of Strood, approximately 10km to the southwest of the Proposed Development. However, the town is shown to have a relatively low heat density of approximately 30-50kWh/m2 (representing a low potential heat customer). The smaller villages within the search radius are considered to have a heat demand that is too small and not sufficiently dense (i.e. less than 30kWh/m2).

Although having potentially larger and denser heat requirements, i.e. low to medium potential, the towns of Sittingbourne and Gillingham are on the other side of the River Medway, a natural barrier, and not considered viable as outlined previously. Medway Maritime Hospital located in Gillingham is considered as having high heat demand; however, its potential in relation to the Proposed Development is minimal due to on-site CHP already serving the site.

Other large heat customers in the area discounted due to their location on the other site of the river estuary include the Kemsley paper mill owned by DS Smith (see the medium density area in the bottom right hand corner in Figure 5.1). Furthermore, all the steam and electrical requirements of this site are met by a local CHP scheme.

Overall, the National Heat Map suggests that the potential for heat export to neighbouring customers is low. However, further analysis has been undertaken using the UK CHP Development Map.

5.2.2 UK CHP Development Map

The UK CHP Development Map6 has been created by DECC to support the development of CHP systems in the UK. Initially produced to assist developments in the planning process, the tool can be used to identify the size and location of existing CHP and District Heating systems and also areas of high heat demand for the development of new systems. Heat densities are expressed in peak demand format (kW/km2), as opposed to the annual heat consumption (kWh/m2) as described by the National Heat Map.

Similarly for the search carried out using the National Heat Map, a search radius of 15km has been used to identify large heat demands which may be viable for connection to a potential heat distribution network.

6http://chp.decc.gov.uk/developmentmap/


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Figure 5-2 – UK CHP Development Map


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The CHP Development Map (Figure 5-2) identifies heat loads of around 10,000 – 50,000kW/km2 (10 – 50W/m2) mainly in the region around the town of Strood on the north coast of the River Medway. The high heat density within both Sittingbourne and Gillingham are considered out of practical range for the distribution of heat from DHC2, for the reasons given above.

Further analysis using this tool enables an appraisal of the sectors which contribute to the heat demand in the area. Figure 5-3 summarises all the heat demand within a 15km radius and in the area of land bound by the Thames Estuary and the River Medway.


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Figure 5-3 –Demand by sector and large heat customers, 15km radius (highlighted)


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Approximately 260MW of heat demand is expected from the domestic sector, accounting for circa 55% of the total heat demand in the search area. However, due to the low-density nature of potential users typically seen in the domestic sector, particularly in predominantly rural areas like those around the Hoo Peninsula, this is not considered an appropriate anchor load for the distribution of heat from the Proposed Development.

The only other major contributor to the total heat demand falls under the category Large Industrial (representing circa 182MWth). Further investigation of this sector confirms that the majority of this demand is attributable to the Liquefied Natural Gas (LNG) terminal operated by the National Grid on the eastern end of the peninsular (approximately 7km from the DHC2 site). This large industrial site, undergoing an extensive expansion, is not however considered viable, since the process heat is supplied through a nearby large scale CHP (Grain CHP Plant). The LNG terminal operations do not therefore represent a viable heat load customer for DHC2.

The remaining heat requirement within the 15km radius, excluding the 182MWth from the LNG terminal and 260MWth, from the low density residential uses is therefore calculated to be 30MWth i.e. <6 % of the identified total heat load within 15km search radius.

Therefore, although the analysis undertaken with the UK CHP Development Map indicates that the local heat demand environment exceeds the recommended minimum for heat as per DECC guidance (minimum 200MWth of heat within 15km), further investigation shows that the majority (circa 94%) of this demand is associated with heat uses unsuitable or unviable for supply from the Proposed Development.

Overall, the analysis conducted using the UK CHP Development Map confirms that the existing local heat demand is not considered sufficiently large, or occurring in sufficient density, to enable an anchor load to be established for the distribution of a local heat network.

5.3 Future Heat Loads The Local Authority (LA) – Medway Council was contacted a number of times throughout 2014 and 2015 to establish the current and future plans for large scale businesses, industries and residential developments in the area. The findings are summarised below.

5.3.1 Lodge Hill (also known as Chattenden Scheme)

Previous searches of future development in the area had identified the Lodge Hill scheme by Land Securities as being a major opportunity in the area. This scheme, which was to be developed on behalf of the Ministry of Defence (MoD) planned to provide up to 5,000 dwellings and associated facilities, in a new development circa 6km to the west of the DHC2 facility.

The developers of the site were contacted to determine the heating and energy strategy for the scheme, with anticipated peak (7 – 9 MWth) and base (1.5 – 3 MWth) thermal loads, estimated using information submitted as part of the outline proposal7, being consistent with the findings of a previous study undertaken in 2009 by Parsons Brinkerhoff8. The identification of this development was previously considered a key opportunity to provide a secure and high demand anchor load for a large district heat network for the area, with heat provided from the DHC2 site. Provision of a large anchor load like the Lodge Hill scheme would significantly improve the technical and economic feasibility of any district heat network.

However, a number of difficulties with the use of the Lodge Hill scheme were identified. These included confirmation from the developer that the construction of the scheme would be phased over 25 years, with approximately 150-200 residential units being completed per year. Such a long phasing programme represented a potential risk; the assessment undertaken indicates that only when the scheme was complete would the end user heat load be sufficient to make connection to a remote heat source such as DHC2 viable, both economically and environmentally. In addition to this, the infrastructure required to transport the heat from DHC2 to the proposed development site 6 km away is significant, and potentially impacts on the overall economic viability of connection.

7 http://www.lodgehill.info/, accessed 31/10/2014 8 CHP-R Assessment, Damhead Creek 2, Parsons Brinckerhoff, June 2009

http://www.lodgehill.info/


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AECOM has previously undertaken the above high-level review of the viability of this option to support the previous section 36 variation application.

However, the Lodge Hill scheme has been challenged by Natural England due to the site’s partial designation as a Site of Special Scientific Interest (SSSI), with the application also being referred to the Secretary of State and the Medway Council. The Lodge Hill development is therefore at significant risk of not being built.

Recent announcements9 confirm that Land Securities now no longer intends to develop the scheme and is pulling out of the development. Although the scheme is still open for approval by the Department for Communities and Local Government (DCLG), the withdrawal of the developer from the scheme casts further and significant doubt on whether the scheme will be realised in the future. It is therefore considered that a CHP connection to the Lodge Hill scheme is currently unviable and therefore not appropriate for further consideration in this assessment.

5.3.2 Goodman International

Goodman International is currently marketing a large warehouse development immediately to the north and east of the DHC2 site. This scheme is planned to accommodate 185,000 m2 of industrial, distribution and/or warehouse space. The anticipated heating demand of this development was expected to be of medium potential (an annual heat demand of approximately 69kWh/m2/year10 is expected). Note that the nature of some future tenant activities is not known and therefore the heat demand could vary. The developers have been approached and confirmed that their energy strategy will provide for a small onsite CHP plant to serve the Goodman International development directly. It is therefore not considered feasible for the DHC2 site to provide heat to the Goodman International development. It has been confirmed that the CHP plant to be installed at the development is too small to make replacement with DHC2 heat viable.

5.3.3 National Grid Site

Outline planning approval has been granted for the National Grid Site development of up to approximately 450,000 m2 of built employment space, which will include business and general industrial uses) with associated infrastructure. The estimated heat consumption associated with this development is approximately 26GWh per year. However, the preferred option for the National Grid Site development is to utilise waste heat from the large scale Grain CHP plant, which is in a closer proximity to the site than DHC2. Therefore, this development is not considered viable for the connection to the DHC2 plant.

5.4 Ranking of CHP Opportunities in the Area A qualitative ranking of the viability of each of the potential end user heat loads and CHP opportunities has been undertaken. The following criteria were considered:

• Likelihood of the CHP opportunity being realised;

• Requirement for onsite works; and

• Requirement for offsite works.

Table 5-2 presents the details of the qualitative screening criteria used in the assessment of viability of each CHP opportunity.

Table 5-3 summarises the potential end user heat loads and CHP opportunities discussed in Sections 5.2 and 5.3 and presents the viability ranking for each opportunity identified.

9 http://www.kentonline.co.uk/medway/news/developer-pulls-out-of-5000-home-43035/ 10 CIBSE Guide F, Table 20.18, Assumed boiler efficiency 75%


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Table 5-2 Description of ranking criteria

Likelihood of CHP Opportunity being

realised Requirement for On Site Works

Requirement for Off Site Works

Likely High Level of Economic Viability

Viable CHP opportunity currently available or anticipated to be viable within 5 years

Viable with requirement for minimal on-site works.

Current design can provide the required heat load and connections for this opportunity with minimal plant works

Viable with requirement for minor off-site works to connect to end user

Ranking 1 1 1

Likely Medium Level of Economic Viability

No viable CHP opportunity within 5 years, but may become viable within 5 – 10 years

Viable with requirement for moderate on-site works.

Moderate plant modifications would be required to provide the heat load and connections for this opportunity

Viable with requirement for moderate off-site works to connect to end user

Ranking 2 2 2

Likely Low Level of Economic Viability

No viable CHP opportunity identified or anticipated to become viable within the next 10 years

Viable with requirement for complex on-site works.

Major plant redesign and works would be required to service this opportunity

Viable with requirement for complex off-site works to connect to end user

Ranking 3 3 3


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Table 5-3 Ranking of potential heat loads

Load Likelihood of CHP Opportunity being

realised Requirement for On-Site Works

Requirement for Off-Site Works

Current Heat Loads

Gravesend - Outside search

radius - Outside search

radius

- Outside search radius

Viability: None Viability: None Viability: None

Strood

- Low load density - No anchor load - No viable CHP

opportunity anticipated within the next 10 years

- Moderate modifications required

- Located approximately 10 km away with no significant natural barriers e.g. rivers

- Moderate off-site works required to connect to end user.

Viability: 3 Viability: 2 Viability: 2

Gillingham

- Low to medium load density

- No viable CHP opportunity anticipated within the next 10 years


- Located on the other side of the River Medway

- Complex and major modifications required crossing the River Medway


Sittingbourne

- Low to medium load density






Sheerness

- Low load density - No viable CHP

opportunity anticipated within the next 10 years






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Load Likelihood of CHP Opportunity being

realised Requirement for On-Site Works

Requirement for Off-Site Works

Future Heat Loads

Lodge Hill Scheme

- No current opportunity

- Developer withdrawal from scheme casts significant doubt on development

- No viable CHP opportunity anticipated within 5 – 10 years

- Minimal modifications required

- Development unlikely to progress

- Located 6km away with no significant natural barriers e.g. rivers

- Moderate off-site works required to connect to end user

- Developer withdrawal from scheme means previous opportunities for heat network ring in doubt

Viability: None Viability: 2 Viability: 2

Goodman International Scheme

- Very small heat load requirement

- Proposed small onsite CHP plant as part of development



- Located within 1km with no significant natural barriers

- Minor off-site works required to connect to end user


National Grid Site

- No current opportunity

- Potentially good heat load

- Proposed connect to a large CHP plant located in a close proximity



- Located approximately 10 km away with some natural barriers e.g. small rivers

-


5.5 Summary of Potential Heat Users and CHP Opportunities An extensive heat customer search has been undertaken to establish the current and potential future heat demand within 15km of the Proposed Development.

5.5.1 Current Opportunities

Searches of current heat customers have indicated that a total of circa 472MWth of heat demand falls within a 15km radius of the Proposed Development (excluding areas situated on land beyond the


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Thames Estuary and the River Medway). Review of the local heat demand has concluded that over 94% of the local heat demand is either not suitable due to the provision of the heat from an alternative low carbon source (in the case of the LNG terminal) or associated with low-density domestic use. With the absence of a large town that typically supports large and densely populated residential developments, the domestic heat demand within the search area is typically of low energy density and does not require sufficiently dense heat demands to support a CHP scheme.

Searches have confirmed that the current heat demand is too low and does not occur in sufficient density to enable a heat network to be technically or economically viable.

5.5.2 Future Opportunities

Further searches of anticipated future heat customers had previously identified the Land Securities development at Lodge Hill (approximately 6km from the Proposed Development) to be the most viable scheme for future connection. However, the withdrawal of the developer from the scheme, following a referral of the scheme to the Secretary of State and the Medway Council (on the basis of that the site’s designation by Natural England as being an SSSI) casts significant risk on whether the scheme will ever commence. In addition, the infrastructure required to transport the heat from DHC2 to the proposed development site 6km away impacts on the overall economic viability of any connection. It is for these reasons that the scheme is now not considered viable for further consideration on this analysis.

Other searches of future heat customers have identified a light industrial site being developed by Goodman International as a potential heat load customer. However, this development is providing its own CHP plant making it not suitable as a heat customer for DHC2. Similarly, the National Grid Site development that includes large employment areas is proposed to be supplied from a large scale CHP plant, which is located next to the site.

Overall, searches have confirmed that there are no viable future heat loads that could be served by a local heat network from the Proposed Development.


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6. CHP Assessment 6.1 Plant Operation The Proposed Development comprises up to 1,800 MWe of generating capacity, predominantly from CCGT units but including up to 300 MWe of open cycle peaking plant generation. For the CCGTs, the gas turbines will burn natural gas in a combustion chamber from where the hot combustion gases expand through the gas turbine to generate electricity. The hot exhaust gases still contain recoverable energy and will be used in the HRSGs to generate steam. The high-pressure steam produced will be used to drive steam turbine equipment to generate additional electricity. The low-pressure (spent) steam leaving the steam turbine equipment will be condensed via air cooler condensers and the resultant condensate returned to the HRSGs for re-use.

For the OCGT peaking plant, the gas turbines will burn natural gas in a combustion chamber. The hot combustion gases then expand through the gas turbine to generate electricity before being expelled to atmosphere. Given their intermittency of operation and the temperature of release of gas to air, CHP opportunities from the OCGT units are not considered realistic or viable and have therefore not been assessed further.

The most viable option for extracting heat for heating distribution purposes is considered to be from the steam turbine, which has the most compatible temperatures for district heating applications and the least impact on power generation. However, the higher the pressure of steam extracted from the turbine, the greater the corresponding loss of electrical efficiency. It is therefore recommended to extract the heat as steam from the low pressure (LP) end of the steam turbine. This can be used to raise low temperature hot water (LTHW), the preferred heat transfer medium for typical district heating applications serving end-uses of space heating and DHW generation.

It is expected that the CCGT units will operate in various running modes including full load (maximum continuous rating) and ‘two shifting’ where the plant is shut down and restarted within a day to meet peak demand. The plant will regularly be shut down for essential maintenance and statutory inspections. The Proposed Development is anticipated to have an annual availability of the order of 93% after annual maintenance and plant failures have been accounted for. The operational life time of the development is anticipated to be in the order of 35 years. Future market economics and the increased use of renewable energy indicate future plant load factors of around 60% are likely.

6.2 CHP Envelope The CHP envelope defines the relationship between the electrical output of the plant and the draw-off of steam for heating purposes, and is characteristic of the plant’s design and procurement. This information will be finalised during the detailed design stage.

6.3 CHP-R Proposal Based on the assessment of the potential heat loads in the area (see Section 5), there are no significant heat customer opportunities anticipated to emerge within the operational life time of the Proposed Development.

The requirement for new plant to be designed to be CHP-R is based on the need to provide the ability to accommodate anticipated viable local CHP opportunities and associated heat loads. As no such opportunities exist or are anticipated for the DHC2 Site, it is therefore considered appropriate that the DHC2 plant is not required to incorporate CHP at this time. To allow for the potential future use of CHP, the proposed DHC2 will incorporate suitable design considerations which will allow for export of heat in the event that a suitable user is identified and the plant layout has considered future potential schemes and future connections to demonstrate that they would still be technically achievable. In addition to the review of potential users prior to commissioning required under condition 52 of the Section 36 consent, potential future opportunities will be identified through regular CHP assessments to be carried out every 4 years as required by the Environmental Permit that the site will operate under.


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6.4 Good Quality CHP CCGT units such as those proposed for the DHC2 Development if operated as a CHP system can be entitled to fiscal and other incentives such as Climate Change Levy (CCL) exemption and Enhanced Capital Allowances (ECA) where applicable, if they qualify under the good quality CHP programme.

In assessing qualification as a Good Quality CHP (GQCHP) system, there are a number of key criteria involved.

In order for the power outputs under annual operation to be fully eligible for CCL exemption and ECAs, the ‘quality index’ of its performance must be greater than 105 for new plants with a Power Efficiency of greater than 20% under annual operation11.

Guidance note GN-1012, available from “quality assurance for CHP schemes” provides the calculation methodology for the Quality Index (QI). The formula below is taken from GN-10, Table GN10-2, and is applicable for the calculation of QI for natural gas fired new plants.

Fuel: Natural gas

Formula: QI = (172 x ηpower) + (115 x ηheat)

(where the installed capacity range is greater than 500 MWe)

ηpower = Electrical efficiency

ηheat = Thermal efficiency (based on useful heat supplied)

The amount of power and heat generated by the plant will depend on its mode of operation.

As the surrounding thermal load environment is not expected to support the Proposed Development’s conversion to CHP operation, the Proposed Development will not be entitled to fiscal and other economic incentives. The determination of Good Quality CHP is therefore not undertaken for this assessment.

11 http://chpqa.decc.gov.uk/guidance-notes/ 12 https://www.chpqa.com/guidance_notes/GUIDANCE_NOTE_10.pdf

http://chpqa.decc.gov.uk/guidance-notes/


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7. Technical and Commercial Considerations

This section provides technical and commercial considerations for the potential development of a CHP based heat network based around the Proposed Development. These are not exhaustive but do outline some key high-level considerations.

7.1 District Heating Network Considerations The network route and the sizing of the network would need to be carefully considered so that suitable provision for current and future connections are allowed for, whilst minimising the length of pipe network installed in order to reduce installation costs and heat losses.

Outside of the site, pipework would likely primarily be routed along highways. In order to do so the Applicant would need to comply with the requirements of the New Roads and Street Works Act 1991 (NRSWA) and other relevant design guides for the installation of buried pipework on highways. Traffic management would be required and limitations to working hours identified. Where works may be required to route the network through private land, negotiations and legal agreements concerning for wayleaves and easements would be required with the land owner, which would influence the installation costs and timeframes.

The number and location of existing sub-surface utilities will influence the potential routing of the district heating pipework. Congested areas may provide a potential constraint/limitation on the district heating network routing which could influence the viability of a network should long diversions be required to route around certain congested areas or if the pipework needs to be buried to such a depth that it becomes impractical to install.

7.2 Heat Supply Considerations

7.2.1 System Resilience

District heating systems can either provide all of the heating demands of the consumer, including peaking and resilience requirements, or just a proportion. If the entire heat demands are provided, the system is dependent on sufficient resilience being delivered from the central heat generating source, typically in the form of top-up and back-up boilers in addition to the heat off-take from the turbine. This is generally a more attractive solution to potential consumers, providing greater space and cost savings from operating only one system, but this does require additional plant to be provided by the district heating supplier to maintain resilience to the system as a whole. The CCGTs within the proposed development are expected to operate at load factors around 60% or lower over their lifetime so there would also be significant time that supplementary heat would be required.

7.2.2 Absorption Cooling

Heat could also be supplied via the district heating network to enable cooling to be generated by absorption chillers on the consumer’s site. This would provide an additional heat load for the system, which could optimise the use of heat particularly during summer, usually the lowest seasonal point of utilisation, when there are typically only DHW demands. A key consideration for this heat supply would be the need to install absorption chillers, and associated heat rejection equipment, on the consumer’s site, with the associated costs and space provisions.

7.3 Commercial Considerations

7.3.1 Heat Price and Connection Charge

Suitable mechanisms for an appropriate heat price and potential connection charge for consumers would need to be established which provide the consumer with an equivalent or better than whole life cost against appropriate alternative systems, while providing sufficient revenues to enable a viable district heating system to be operated. As there are no viable heat customers or indicative loads identified in the area, indicative costs cannot be estimated at this time.


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7.3.2 Heat Supply Agreements

The length of heat supply agreement that a consumer can enter in to needs to be considered. District heating system heat supply agreements are often long term in nature in order to ensure a revenue stream against the investment made in constructing the network and installing the CHP plant. However, as viable heat customers have not been identified, no heat supply agreements will be required for this development.

7.3.3 Number of Consumers

In order to ensure that the district heating system is viable it is necessary to establish sufficient numbers of commitments from consumers to connect, particularly at the early stages of a project. Again, given that there are no identifiable heat load customers (currently and in the future) that are considered potentially viable, there are not expected to be any commitments to connect for DHC2.


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8. Conclusions This study has summarised, via a variety of sources, the heat demand requirements of users in the vicinity of the Proposed Development. The estimates of heat demand have been based on data gathered from the recognised National Heat Map and the UK CHP Development Map. Although there are limitations regarding the actual heat demand the developments identified in the searches exhibit, the overall accuracy of the heat demand environment in the vicinity of the Proposed Development is considered to be reliable.

The searches have confirmed that there is no appropriate single significant user (>20MWth) of heat within the 15km radius of the site. The only identifiable load of this magnitude is the LNG terminal on the east of the peninsula. However, the process ‘heat’ load is served on site through a nearby large scale CHP plant. Hence the LNG terminal is not suitable as a heat customer. Other local heat loads are demonstrated to vary considerably in their magnitude and proximity to the Proposed Development.

The searches have not identified any potential future heat customers that could be considered viable. Although the proposed development at Lodge Hill was previously considered potentially viable, the withdrawal of the developer from the scheme casts significant doubt on whether the scheme will ever go ahead. The Lodge Hill development is therefore not currently considered a viable future opportunity.

In conclusion, it is not considered viable for the Proposed Development to operate as a CHP, as there are insufficient heat consumers available within a reasonable proximity, either currently or expected in the future operational lifespan of the DHC2 scheme. It is therefore considered appropriate that the DHC2 plant is not required to incorporate CHP at this time. To allow for the potential future use of CHP, the proposed DHC2 will incorporate suitable design considerations which will allow for export of heat in the event that a suitable user is identified and the plant layout has considered future potential schemes and future connections to demonstrate that they would still be technically achievable. In addition to the review of potential users prior to commissioning required to meet condition 52 of the Section 36 consent, potential future opportunities will be identified through regular CHP assessments that will be carried out every 4 years as required by the Environmental Permit the site will operate under.

Medway Council has agreed to the revision of the obligation in the Section 106 Agreement entered into when the original Section 36 Consent was issued to install pipework to the site boundary during the plant construction for a potential, as yet undefined future CHP scheme. A deed of variation was agreed with Medway Council (September 2015) in that the necessary pipework and plant for CHP will be installed only when ScottishPower (DCL) Ltd has entered into a contract with a third party for the supply of heat from DHC2; however this did not require any variation to the current CHP condition as set out at condition 52 of the Section 90 Direction.

ScottishPower (DCL) Ltd will therefore undertake a periodic review (every 4 years) of CHP potential for DHC2. This review may include:

• maintaining a dialogue with heat users already approached;

• carrying out reviews to determine if there have been sufficient changes in circumstances to warrant a new technical and financial review; and

• regularly re-visiting the technical and economic assessments at appropriate points in the future if a change in circumstances warrants.


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Limitations

AECOM Infrastructure & Environment UK Limited (hereafter referred to as AECOM, formerly known as URS) has prepared this Report for the sole use of ScottishPower DCL Limited (“Client”) in accordance with the Agreement under which our services were performed (email proposal 26th October 2015 and instruction to proceed dated 26th November 2015). No other warranty, expressed or implied, is made as to the professional advice included in this Report or any other services provided by AECOM. This Report is confidential and may not be disclosed by the Client nor relied upon by any other party without the prior and express written agreement of AECOM.

The conclusions and recommendations contained in this Report are based upon information provided by others and upon the assumption that all relevant information has been provided by those parties from whom it has been requested and that such information is accurate. Information obtained by AECOM has not been independently verified by AECOM, unless otherwise stated in the Report.

The methodology adopted and the sources of information used by AECOM in providing its services are outlined in this Report. The work described in this Report was undertaken between October 2014 and December 2015 and is based on the conditions encountered and the information available during the said period of time. The scope of this Report and the services are accordingly factually limited by these circumstances.

Where assessments of works or costs identified in this Report are made, such assessments are based upon the information available at the time and where appropriate are subject to further investigations or information which may become available.

AECOM disclaim any undertaking or obligation to advise any person of any change in any matter affecting the Report, which may come or be brought to AECOM’s attention after the date of the Report.

Certain statements made in the Report that are not historical facts may constitute estimates, projections or other forward-looking statements and even though they are based on reasonable assumptions as of the date of the Report, such forward-looking statements by their nature involve risks and uncertainties that could cause actual results to differ materially from the results predicted. AECOM specifically does not guarantee or warrant any estimate or projections contained in this Report.

Where field investigations are carried out, these have been restricted to a level of detail required to meet the stated objectives of the services. The results of any measurements taken may vary spatially or with time and further confirmatory measurements should be made after any significant delay in issuing this Report.

Copyright

© This Report is the copyright of AECOM Infrastructure & Environment UK Limited, a wholly owned subsidiary of AECOM. Any unauthorised reproduction or usage by any person other than the addressee is strictly prohibited


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Appendix A – Site Location


Page 30


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Appendix B – CHP-R Assessment Form


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# Description Units Notes/Instructions

Requirement 1: Plant, Plant Location and Potential Heat loads

1.1 Plant Name Damhead Creek 2

1.2 Plant Description

- Natural gas fired CCGT / OCGT peaking plant - Total generating capacity of up to 1,800MWe - Total rated gross thermal input:

o 2501 MW (LHV) CCGT o 734 MW (LHV) OCGT

- Power rating 1,800 MWe - Plant design – see section 2.2 of this report

1.3 Plant Location (Postcode/GridRef) Postcode ME3 9TX. See Appendix A - Site Location.

1.4 Factors Influencing Selection of Plant Location

- Increasing generation capacity of existing power station site

- Sufficient land available: Sufficient land has been identified; see plant layouts in Appendix C.

- Current land use: undeveloped land adjacent to the existing DHC1 site, on the existing power station site

- Potential future CHP opportunities: No immediate opportunities

- Compatibility with relevant Local Plans: the Proposed Development is not in conflict with Medway Local Plan

- Proximity to suitable utilities and grid export connections: Existing power station developments have provided appropriate provisions in proximity to the site.

- Suitability for CCS: CCS is applicable to the site. Suitable provisions have been allowed for.

1.5 Operation of Plant

a) Proposed Operation Plant Load % 100%

b) Thermal Input at Proposed Operational Plant Load MW 2,501 MW (LHV) CCGT / 734 MW (LHV) OCGT

c) Net Electrical Output at Proposed Operational Plant Load MW 1,800 MW CCGT or 1,500 MW CCGT / 300 MW OCGT

d) Net Electrical Efficiency at Proposed Operational Plant Load % 60% CCGT / 34% OCGT (LHV input)

e) Maximum Plant Load % 100% or 1,800 MW

f) Thermal Input at Maximum Plant output MW 2,501 MW (LHV) CCGT / 734 MW (LHV) OCGT

g) Net Electrical Output at Maximum Plant output MW 1,800 MW CCGT or 1,500 MW CCGT / 300 MW OCGT

h) Net Electrical Efficiency at Maximum Plant output % 60% CCGT / 34% OCGT (LHV input)

i) Thermal Input at Minimum Stable Plant output MW 1,445 MW (LHV) CCGT / 551 MW (LHV) OCGT

j) Net Electrical Efficiency at Minimum Stable Plant output % 55% CCGT / 27% OCGT (LHV input)


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1.6 Identified Potential Heat Loads As detailed above no immediate suitable heat loads have not been found.

1.7 Selected Heat Load(s)

a) Category (e.g. Industrial/District Heating)

A mixture of industrial, commercial and residential heat uses have been considered.

b) Maximum Heat Load Extraction Requirement MW N/A

1.8 Export and Return Requirements of Heat Load

a) Description of Heat Load Extraction

Low pressure (LP) steam

b) Description of Heat Load Profile

Variable

c) Export Pressure bar a It is likely that LP steam would be used as the heat transfer medium if any District heating applications for space heating and/or DHW generation had been identified.

d) Export Temperature 0C District heating applications for space heating and/or DHW generation would be in the region of 80-95 0C.

e) Export Flow t/h

f) Return Pressure bar a

District heating applications for space heating and/or DHW generation would likely be in the region of 3 bar. For industrial process use this would be specific to future connections requirements.

g) Return Temperature 0C

For district heating applications for space heating and/or DHW generation would likely be in the region of 50-60 0C. For industrial process use this would be specific to future connection requirements.

h) Return Flow t/h N/A

Requirement 2: Identification of CHP Envelope

2 Comparative Efficiency of a Standalone Boiler for supplying the Heat Load

90 % LHV

2.1

a) Maximum Heat Load Extraction at 100% Plant Load MW

No viable heat loads (currently or future) in the area. CHP not viable at this time. To allow for potential future use of CHP, the proposed DHC2 will incorporate suitable design considerations which will allow for export of heat in the event that a suitable user is identified.

b) Maximum Heat Extraction Export Flow at 100% Plant Load t/h

c) CHP Mode Net Electrical Output MW


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at 100% Plant Load

d) CHP Mode Net Electrical Efficiency at 100% Plant Load %

e) CHP Mode Net CHP Efficiency at 100% Plant Load %

f) Reduction in Primary Energy Usage for CHP Mode at 100% Plant Load

%

2.2

a) Maximum Heat Load Extraction at Minimum Stable Plant Load MW

No viable heat loads (currently or future) in the area. CHP not viable at this time. To allow for potential future use of CHP, the proposed DHC2 will incorporate suitable design considerations which will allow for export of heat in the event that a suitable user is identified

b) Heat Extraction Export Flow at Minimum Stable Plant Load t/h

c) CHP Mode Net Electrical Output at Minimum Stable Plant Load MW

d) CHP Mode Net Electrical Efficiency at Minimum Stable Plant Load

%

e) CHP Mode Net CHP Efficiency at Minimum Stable Plant Load %

f) Reduction in Primary Energy Usage for CHP Mode at Minimum Stable Plant Load

%

2.3

Can the Plant supply the Selected Identified Potential Heat Load (i.e is the Identified Potential Heat Load within the 'CHP Envelope')?


Requirement 3: Operation of the Plant with the Selected Identified Heat Load

3.1 Proposed Operation of Plant with CHP

a) CHP Mode Net Electrical Output at Proposed Operational Plant Load

MW


b) CHP Mode Net Electrical Efficiency at Proposed Operational Plant Load

%

c) CHP Mode Net CHP Efficiency at Proposed Operational Plant Load %


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d) Reduction in Net Electrical Output for CHP Mode at Proposed Operational Plant Load

MW


e) Reduction in Net Electrical Efficiency for CHP Mode at Proposed Operational Plant Load

%

f) Reduction in Primary Energy Usage for CHP Mode at Proposed Operational Plant Load

h) Z Ratio

Requirement 4: Technical Provisions and Space Requirements

4.1 Description of Likely Suitable Extraction Points

No viable heat loads (currently or future) in the area, CHP not viable at this time. To allow for potential future use of CHP, the proposed DHC2 will incorporate suitable design considerations which will allow for export of heat in the event that a suitable user is identified.

4.2

Description of Potential Options which could be incorporated in the Plant, should be realised outside the 'CHP Envelope'

4.3

Description of how the future Costs and Burdens associated with supplying the Identified Heat Load / Potential CHP Opportunity have been minimised through the implementation of an appropriate CHP-R design

4.4

Provision of Site Layout of the Plant, indicating Available Space which could be made available for CHP-R

Requirement 6: Economics of CHP-R

6.1 Economic Assessment of CHP-R


BAT Assessment

Is the new plant a CHP plant at the outset (i.e. are there economically viable CHP opportunities at the outset)?

No

If not, is the new plant a CHP-R plant at the outset? Yes

Once the new plant is CHP-R, is it BAT? Yes


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Appendix C – Proposed 1,800 MW CCGT with Peaking Plant Scheme Option Layout


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Appendix D – List of Organisations Consulted


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List of organisations consulted as part of CHP-R Assessment:

1. Medway City Council

2. Goodman International

3. Land Securities

4. The Centre for Sustainable Energy

List of organisations consulted as part of CHP-R Assessment, Damhead Creek 2, Parsons Brinckerhoff, June 2009:

1. DECC – Electricity Developments Consents Team

2. DEFRA – Climate and Energy: Households and Markets

3. CHPQA

4. Government Office for the Regional Planning Bodies: South East of England

5. Medway Council Development Control

6. CHPA – Combined Heat and Power Association

7. The Energy Saving Trust

8. NHS Estates/Strategic Health Authority

9. Confederation of Paper Industries

chp-r report damhead creek 2 power station · 2016-02-29 · a chp system generates electricity...

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