www.sustainable-energy.co.uk

Dr Gabriel Gallagher Rehau District Heating Workshop Cardiff Millennium Centre 22 September 2016

Developing District Energy Projects Consultant Experience

Introduction

• Independent renewable energy and district heating consultancy based in Cardiff

• Full cycle of services since 1998

• 12 energy professionals including CIBSE Heat Network Consultants

• Developed over 100MW of low carbon heating and power projects

• Designed and overseen installation of over 20km of district heating network

Share experience and lessons learned from 18 years of designing and overseeing implementation of district energy networks

Recent District Energy Projects

• Lead Consultant for first phase build out of 5MW city centre district heating – Bristol City Council

• Design of biomass scheme and integration of biomass heat and gas CHP into 13MW district energy scheme – Blaenau Gwent CBC, Ebbw Vale

• Designer and clients engineer for 2.5MW biomass district heating for Wales’ largest Social Housing district heating Scheme – Newport City Homes, Duffryn

Recent District Energy Projects

• Design and project management of 1.7km heat network – Portmeirion Village, Gwynedd

• Masterplanning, feasibility and detailed design for Heat Network Delivery Unit (BEIS) district energy projects – Bradford MDC, Wakefield Council, Brighton and Hove CC, Stratford-on-Avon DC, Flintshire CC, Bristol CC

• Assessment of strategic heat network (>15km) for heat offtake from Energy From Waste Plants at Avonmouth – South Gloucestershire Council and Bristol City Council

Stages for Successful Project Development

5. Planning and permitting

6. Tender, procurement, value engineering and contracting

7. Construction and installation project management

8. Commissioning and acceptance testing

9. Monitoring and management

1. Heat mapping and Masterplanning

2. Feasibility assessment

3. Concept development and outline design

4. System specification and detailed design

Masterplanning and Feasibility

Energy Demand Assessment

Detailed and robust hourly energy demand analysis of each building and network option

Assessment of Risks and Barriers Effective identification, assessment, mitigation and management of all risks – technical, financial, commercial, planning etc

Assessing Network Options

Modelling Heat Network and Low Carbon Technology Assessment

Design of Energy Centre Equipment

– Maximise use of low carbon / renewable heat

– Allow heat supply to meet a large variation in daily and seasonal heat loads

– Future proof for additional future capacity

Network design

– Low temperature

– Variable flow rates

– Minimising heat losses

– Future proof for future connections

Financial Assessment

Network Phase Energy

source

Estimated

capital costs

25 year financial case 40 year financial case

Payback IRR NPV Payback IRR NPV

City

Centre

1

Gas CHP

£2,016,353 13 years 6.2% £686,818 14 years 6.8% £1,250,125

2 £4,092,623 9 years 10.8% £4,178,352 10 years 10.9% £6,188,109

3 £6,214,314 11 years 8.4% £4,016,814 12 years 8.8% £6,522,968

Hospitals

1 Gas CHP

£4,982,291 8 years 13.8% £7,520,935 8 years 13.5% £10,715,721

2 £7,857,413 10 years 10.2% £7,112,659 10 years 10.3% £10,768,646

Financial case period 25 years 40 years

CHP heat output 2.5 MW

% heat supplied by gas CHP 74%

% heat supplied by auxiliary 26%

Electricity generated 16,271 MWh

% private wire1 63%

% export 37%

Capital expenditure

Energy source costs £2,086,900

Network costs £3,091,695

Contingency 20%

Total £6,214,314

IRR 8.4% 8.8%

Net present value £4,016,814 £6,522,968

Payback 11 years 12 years

Carbon saving 4,382 tonnes

1 Percentage of power generated by CHP plant.

Technical Considerations

• Heat load profiles – Peak demand

– Diurnal profiles

• Technology Assessments – Renewable, low carbon,

EfW etc

• Thermal Storage Sizing – Maximise efficiency and project returns

– Minimise plant cycling

• Hydraulic design – Control and temperatures in Primary, Secondary and Tertiary circuits

– Configuration of fossil fuel to maximise contribution by low carbon technologies

– Metering for EED and RHI compliance

Case Study Examples Local Schemes

Experience in delivery of design, clients engineer and commissioning and handover services for:

• Social Housing

– Bristol City Council

– Newport City Homes

• Public sector buildings – education, offices, leisure

– Blaenau Gwent County Borough Council

• Private development

– Portmeirion Village

Bristol City Council – Phase 1

• Initial feasibility - 2013

• Detailed design and planning - 2014

• Construction of energy centre - 2015

• Final heat network connection started - 2015

• Commissioning of network - 2016

• Design future-proofed for connection to school, hotels, private residential customers

• Designed to allow future input of additional low carbon heat

Sustainable Energy engaged to extend network to Private Heat Customers 2017 +

Bristol City Council Phase 1 Feasibility and outline design

17 Buildings connected in phase 1 First heat network cluster in Bristol

Bristol City Council Phase 1 Network Construction Management

REHAU flexible DN150 to help navigate underground services in narrow route between buildings

DN200 steel network for connection to future heat import from potential schemes into Phase 1 network

Bristol City Council Phase 1 Energy Centre Build

1MW biomass boiler and thermal store into restricted space in underground energy centre

Key Points & Lessons

• Designing financially viable scheme for current technologies and conditions but future proofing to allow future connections and import of additional low carbon heat

There will be changes between initial planning and build out!

• Consider multi-utility approach to work with other network installers – Fibre Broadband

– Private wire

The Works, Ebbw Vale Integrating Renewable Heat into an Existing Network

• 10MW district heating

– School, leisure centre, college, offices, archives

• 3 x 2,900kW gas boilers

• 1 x 350kW gas fired CHP

• 2 x 500kW wood pellet boilers

• 35,000lts thermal stores

• Multi-stage pumps to increase turndown

• Primary network temperature reductions

• Secondary side modifications

75% of heat demand met with low carbon heat in Year 1

The Works, Ebbw Vale Integrating Renewable Heat into an Existing Network

Key Points & Lessons

• Early phases of a future proofed scheme should be financially robust as planned customers may take longer to connect or developments may not be brought forward or built out

Reduced initial uptake can lead to proportionally high heat losses and operational costs

• Renewable Heat Incentives will improve financial viability and could make up initial funding gap

• Design pumping regime to expand with heat load to allow control of temperatures and flow rates in network – Pipes larger than required at low demand

– Multiple smaller pumps and equipment

Duffryn Social Housing Scheme • Wales largest district heating scheme

• Low cost, low carbon heating to 1000 homes

• Principal Contractor - British Gas

• 2.5MW wood chip boiler and 50,000lts thermal store

• Sustainable Energy acted as Principal Designer, Commissioning Manager for handover and provided RHI accreditation services

Key Points & Lessons

• Planning construction for ‘Keeping Heat On’ and delivering in line with budget – Key tasks for adding heat metering, connecting into existing heating

systems

– moving key utilities in construction area

Portmeirion Village

• One of Wales’ premier visitor attractions

• 24 Historic buildings including castle, hotel and swimming pool

• Site with steep gradient

• 1MW wood chip boiler

• 1.7km of Rehau network

• 70/40 design upgrades for secondary heating systems

• Sustainable Energy acted as Designer, Project Manager and Client Engineer

Portmeirion Village

1.7km of heat network from hotel at sea level to Castle at 40m above

Key Points & Lessons

• Make case for secondary system upgrades and include in design in order to achieve Best Practice

– Energy centre and heat network significant investment

– Immediate secondary system upgrades may be cost prohibitive and cause further significant disruption

– Secondary system upgrades designed and some key connections implemented

– Full conversion of all upgrades carried out in replacement programme to spread out investment and limit disruption

Summary

• All project stages must be detailed and robust

• Detailed assessment of risk required

• Future-proofing should be considered at feasibility stages

• Secondary side systems require assessment

• Effective project management of construction phase required to deliver in line with budget and minimise disruption

• Collaborative approach to network delivery will pay dividends

Questions