anahat energy enhanced energy audit emma & simonby 4,400 kwhs per year to 15,180 at an annual...

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Prepared forAshburton Futures, MASHFFF Project

AddressThree Bedroom Semi-Detached Cornish Unit

Date14th March 2012 Website: www.anahatenergy.com.

Tel: 0845-074-5915

Enhanced Energy Audit & Renewable Options Analysis

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This report would not have been possible without the funding and support of the organisations below. We would like to thank the funders for allowing this report to be possible.

Funders

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1. Summary1.1 Key report messages & photos1.2 Overview of property details1.2 Heating Energy Use & Reduction Opportunities1.3 Electrical Energy Use & Reduction Opportunities1.4 Renewable Options at Your Property1.6 Future Energy Bills & CO2 Reduction Pathway

2.0 Heating & Hot Water2.1 Heating & hot water assumptions2.2 Theoretical energy use for heat & hot water & thermostatic sensitivities2.3 Theory versus reality 2.4 Main heat losses in property2.5 Analysis of main heat & hot water reduction actions2.6 Air infiltration analysis

3.0 Electricity3.1 Results of electrical audit & top areas of demand3.2 Analysis of main electrical load reduction actions

4.0 Renewable Options4.1 Renewable energy financial incentives in the UK4.2 Solar PV generation potential & financial analysis4.3 Solar Thermal generation & financial analysis4.5 Ground Source Heat Pump (GSHP) generation & financial analysis

5.0 Appendix5.1 Assumptions & glossary5.3 Disclaimer

Contents

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1) Introduction

This is one of twelve energy audits commissioned by Ashburton Futures as part of its 'Making Ashburton-Style Homes Fit For the Future' project. This took place during February and March 2012 and was funded by the UK Government Department of Energy and Climate Change through it's 'Local Energy Assessment Fund' (LEAF). All 12 reports and the films that go with them can be seen at www.ashburtonfutures.org.uk. The films are at www.youtube.com/ashburtonfutures. All material is published under a Creative Commons BY-NC licence, so it is free for non commercial use by anyone else, as long as Ashburton Futures is credited.

This report aims to show the main areas where energy use can be reduced in this house, saving money and reducing its carbon footprint. This house was chosen because there are many others in Ashburton that are similar, so it's very likely that any lessons learned here are just as relevant to other houses of similar age and design. It also looks at whether any renewable energy generation might be suitable for the property. To take into account every single factor that is relevant is extremely complicated, so this report cannot guarantee to model correctly every way that energy is lost or used. However, we have used a sound methodology to ensure the information provided is as accurate as possible.

2) Heating Strategy

The property is heated by a relatively new and efficient Worcester Greenstar 24 kW combination boiler. The boiler has a very good seasonal efficiency of 89.1% and a hot water efficiency of 66.9% (ref: SEDBUK.) Heating within the property is regulated through the use of a boiler timer, thermostat and thermostatic radiator valves (TRVs) which is the best strategy.

The key issue with the heating strategy is the current thermostat placement. It is right next to the front door which is draughty and will be opened throughout the day. This will force the thermostat to think it is colder than it actually is, forcing the boiler to work for longer and using up more energy than required.

Hence, the key recommendation is to move the thermostat to a more appropriate position. Again this should be in a place which is away from cold draughts, at shoulder level and which is representative of the property temperature requirements. e.g. between the kitchen and hallway.

In addition, whilst this is done it may be worth upgrading the current analogue thermostat to an electronic one. Electronic thermostats will provide a greater level of temperature accuracy (provided on the screen) and greater accuracy with regards to target temperature (within 0.1ºC.) As such, electronic thermostats can save up to 10% on energy use when replacing inaccurate analogue equivalents. This can be discussed in more detail if required.

1.1 Key Report Messages (1)

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3) Theory vs. Reality

The client used an estimated 24,900 kWhs at a cost of £950 for heating the property and providing hot water in the last 12 months.

Of this, 22,000 kWhs were from the gas boiler and 2,900 kWhs from 2m3 of wood (assuming 500kg / m3) that were burnt in an open fire in the living room.

The thermostat setting has recently been lowered from 23ºC to a more appropriate temperature of 20ºC. Using a target temperature of 23ºC (Monday – Sunday, 8 months of the year) our analysis suggests that for the property a long-term annual average heating & hot water demand of 19,600 kWh should be expected prior to any changes to the building fabric. At the new setting of 20ºC, this reduces by 4,400 kWhs per year to 15,180 at an annual cost of £578 - £370 below current fuel bills for heating and hot water.

Clearly 2011 was a very cold winter and this probably accounts for some of the discrepancy, however there is still scope for reduction should the thermostat be placed more appropriately.

It should also be noted that reducing the thermostatic setting from 20ºC to 19ºC would have a substantial relative affect on heating demand – reducing the theoretical demand by 9.5%, 1,480 kWhs per year, an additional saving of £55 per year.

4) Heat Energy Reduction

During our energy assessment numerous opportunities to reduce the energy demand at the property were identified through a combination of insulative upgrades and draught proofing. The different options are split below:

a. RoofThere are 2 different roofs to consider at the property.

Figure S1: Colder air (blue) able to enter round edge of front door

Figure S2: Colder air (blue) able to enter through extension doorway


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Figure S3: Colder air (blue) able to enter through under extension wall

Figure S4: Colder air (blue) able to enter through open ceiling vent(s)

i) Mansard roof of the original property: has a very low level of insulation (50mm mineral wool) and accounts for 6.5% of the total heat loss at the property. This should be increased to meet / beat current building regulation levels by adding 250mm of mineral wool (building regs are 270mm.) This could be done by adding loft stilts onto the existing boards (available from major DIY stores), providing space below for the additional insulation and above for the current storage capability. Our analysis suggests this would save an estimated 1,270 kWhs per year or £50 per year in energy bills.ii) The flat roof of the extension: has 100mm of mineral wool which was visible through a hole left by a plumber. There was no opportunity to investigate whether more insulation could be laid (by removing the felt and putting it in directly from above.) Adding the equivalent of another 50mm of solid insulation (affixed with ballast to the existing roof) would save only an estimated 238 kWhs or £10 per year on energy bills - hence, it is not recommended as an action.

Clearly the main pitched roof is the priority (point i above) and we would recommend speaking to the South West Energy Saving Trust Advice Centre on 0800 512 012 who will advise on funding and / or refer you to a local company for a free survey.

b. WallsThe property has a mixture of varied and unusual structural types.

i) The Extension: This has, what is assumed to be, an unfilled cavity wall which has had insulated plasterboard affixed to the inside by the current owners. We would recommend that the client investigate filling the cavities. If the cavities could be filled (subject to moisture and other issues not presenting any problems) this intervention is expected to save £24 per year on energy bills (~600 kWhs p.a.) As with for the roof, for independent advice (especially on current funding opportunities,) we would recommend contacting the South West Energy Saving Trust Advice Centre on 0800 512 012. They will also help to refer you to a local company for a free survey. The typical cost for filling cavities is between £150 - £200.i) Timber frame "Mansard" (1st floor): The 1st floor has a timber frame structure with plasterboard (inside), a small amount of mineral wool insulation (50mm assumed) and tiles directly on the outside. In properties of a similar age and structure, the insulation in the timber frame has been found to be inappropriate and sometimes to have “slumped” to the bottom of the wall. Therefore, we would recommend that, if possible, some of the external tiles are removed at a suitable time to investigate the state of insulation and the options available to upgrade (if possible.)


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We have analysed the potential opportunity by adding 100mm of solid insulation to the first floor walls (assuming none there now.) This action, if possible, would save in the order of 1,250 kWhs per year or £45 in expected energy costs. We would recommend engaging an experienced contractor who understands issues in relation to moisture and thermal bridging. In addition, it is worth noting the requirement for the careful sealing of all joins between insulation boards.

In relation to the downstairs walls of the older property there is nothing to focus on presently as they are assumed to have filled cavities.

c. GlazingThe windows downstairs (and in the bathroom upstairs and next to the stairs) are all relatively modern double-glazing units which were shown to have relatively good levels of draught-proofing during the depressurisation test.

However, the old double-glazed units in the bedrooms were all shown to have poor levels of draught-proofing (due to some ill-fitting) and also have metal frames - conducting heat more effectively away from the home. As such, the client may wish to investigate changing the glazing units in the bedrooms for modern installations. This would reduce heat loss and air infiltration – improving the overall thermal comfort. Double-glazing does not generally have a good financial payback. New units would save an estimated £13 per year with an installation cost in the order of £800. However, it should be noted that this calculation does not take account of the beneficial reduction in draughts.

d. DraughtsHeat loss in a building occurs in two ways:

1) as a result of losses through the building fabric, & 2) due to losses through unwanted ventilation (also known as air infiltration.)

Our calculations suggest that air infiltration accounts for the joint highest level of heat loss (26%) – equivalent to that calculated for the walls. This was quantified using a blower door test which determined that the level of air-tightness (with the fireplace sealed) is 75% higher than current building regulations for a new property of the same footprint and volume. As such, there should be significant opportunities to reduce heat loss from draughts.

Figure S5: Cold air (blue) infiltrating through gaps around loft hatch

Figure S6: Cold air (blue) infiltrating through the skirting board and from floorboards in bedroom


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Figure S8: Cold air (blue) infiltrating around bedroom window(s)

Figure S7: Colder air (blue) infiltrating through small cracks in the ceiling / wall join upstairs

The following areas were determined to be focal areas during the site survey:

i) Open fireplace: The fireplace in the main living room can either be a) converted to using a wood burner which would reduce air infiltration (as the chimney would be blocked) and increase heat use efficiency levels (from 20% to 80%), or b) blocked when not in use by using a chimney (also known as a plumber’s) balloon.ii) Extension / old home join: during the pressure test air could be felt at the point where the extension joined the old doorway. Simple sealant would minimise this area of heat loss. iii) Ceiling opening in extension hallway: A hole has been left in the extension ceiling which allows cold air to enter the property. This should be sealed.iv) Bedroom windows: As mentioned above, the bedroom windows are “leaky." Simple draught-proofing strips would make a big headway in reducing the ability for cold air to enter through the gaps.v) Roof vents in bedrooms: 2 roof vents exist in the upstairs bedrooms. They are connected directly to the loft and allow cold air to enter. It is believed that they were part of the original building to minimise moisture (when the building fabric was very different.) These could be sealed.vi) Floorboards in bedrooms: The floorboards showed evidence of air infiltration during the blower door test – believed to be evidence of an air channel from the wall through to the floor. The existing gaps in the floorboard could be sealed relatively easily.vii) Loft hatch: this was shown to allow air through gaps around the hatch during the depresurisation test. This could be reduced with simple draught-proofing.viii) Ceiling cracks: small cracks between the 1st floor ceiling and the loft were shown to allow cold air to infiltrate. These could be sealed accordingly.

e. Radiators & Exposed PipeworkThere is exposed pipework on external walls which should be insulated to ensure the maximum amount of hot water reaches the radiators for heating – minimising energy losses in the process. In particular, it is worth mentioning that there is a large amount of exposed pipework in the utility room - which is unheated and has single skin walls. It is worth noting that sealing the joins in the pipe insulation with insulating tape will make this much more effective.

In addition, there are no radiator reflectors installed (which are very cheap and simple to install.) These should be fitted behind radiators on outside walls, in order to reflect heat back into the rooms.


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4) Electrical Load & Energy Reduction

The current electricity tariff is appropriate at 13.1 pence / kWh and there is no need to necessarily find a lower rate.

The on-site electrical audit under-estimated the current annual electrical demand by 20%, yet should still provide a suitable representation of electrical use at the property.

The key use is the 3 kilo Watt (kW) electric heater in the studio which is assumed to be on for 2.5 hours per day, 5 days per week for 5 months of the year. There is little that can be done about this unless the thermostatic setting can be reduced whilst maintaining an appropriate level of thermal comfort.

5) Energy Generation

The roof of the property faces 15 degrees east of south, yet with a huge eucalyptus tree directly in front. As such, due to significant shading issues, all roof mounted systems are not deemed to be appropriate. However, the client mentioned that the tree could be cut down at some point, and so an analysis of solar PV has been undertaken for future reference – although noting that tariff levels could change and are likely to.

Due to a high level of hot water demand, solar thermal has also been assessed on the basis that the tree has been felled.

We would not recommend biomass due to access / storage, or ground source heat pumps (GSHP) due to the lack of external space and the high heat distribution system i.e. radiators.

i) Solar Photovoltaics (PV, Electricity)The property roof faces 15 degrees east of south, with a roof pitch of 30 degrees from the horizontal. Ignoring the shading from the tree, approximately 9m2 of roof space is available which could allow the installation of up to 1.1 kilo Watt peak (kWp.)

This maximum system size would provide a predicted annual energy generation of 1030 kWh per annum (~930 kWh / kWp), 27% of the current annual electricity demand.

In investment terms, the maximum system size would provide a poor internal rate of return (IRR) of 3.4% with an inflation-adjusted payback of 17 years.


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ii) Solar Thermal (Hot Water)Subject to the assumption that the tree is felled, our analysis indicates that 3.5m2 of solar thermal panels would be required, providing just under 100% of the predicted demand in summer.

This size of system would provide approximately 60% of the total annual hot water demand and, with the Renewable Heat Incentive, provide a payback in the order of 11 years – a relatively good investment.

This is based on an installation cost assumption of £5,500 – higher than normal due to the existing combination boiler. This would include a new hot water tank, panels and installation.

6) Funding and finance

Funding for renewable energy generation is available through the Government’s Feed in Tariff and the Renewable Heat Incentive (see Section 4.1).

In autumn 2012 the Government will be launching the Green Deal, a new finance package to fund energy efficiency measures in properties and businesses. By providing a loan to the property, the Green Deal avoids the need to pay for measures upfront. It will allow the property owner to pay off the loan with the savings that they are making through reduced bills. Most, if not all of the energy efficiency measures mentioned in the report will be covered under the scheme.

For more information visit the Department of Energy and Climate Change website at http://www.decc.gov.uk/en/content/cms/tackling/green_deal/green_deal.aspx

7) Conclusion

In conclusion, there are numerous areas to focus on at the property to help reduce energy. We hope that the report helps to provide focus with regards to the different areas described above.

If you have any questions then please do not hesitate to contact us at your convenience.


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Below is a summary of the main property details

Main Propoerty Details Fuel Use SummaryFuel Type kWh / year £ / yearCoal n/a n/aElectric 3,762 £492Gas 22,067 £794LPG n/a n/aOil n/a n/a

Dimensions & Orientation Wood 2,822 £154Number of floors 2Average room height 2.35 Main Boiler SystemApprox. floor space (m2) 104.0 Fuel GasApprox. volume (m3) 260.0 Boiler type CombiOrientation (degrees) 165 Boiler power (kW) 24Roof pitch (o from horiz.) 30 Boiler efficiency (%) 89.1%

Building FabricType

1950

Ashburton, DevonDetached Cornish Home

DescriptionSolid w/carpet & linoCavity filled, unfilled w/insulation &timber50mm mineral wool

FloorsWallsRoofWindows

ClientProperty AddressProperty TypeProperty age

Double glazing (varying quality)

Ashburton Futures, MASHFFF ProjectDate of Energy Audit 14th March 2012

1.2 Overview of Property

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Figure E1: Estimated energy loss / use by type for heating & hot water24,889£948

Table E1: Top 5 actions by financial payback to reduce energy for heating & hot water at your property

immediate0.3 0.90.5 7.01.6 12.2

2.0

Figure E1 shows how energy for heating & hot water (electric / non-electric) is estimated to be used in your property. This is based on our survey, & our understanding of how buildings like yours lose heat. Table E1 shows the top 5 actions to reduce energy, ranked by financial payback.

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Annual Saving (£)

Total Annual Cost

Energy Reduction (kWh)Action

Financial Payback (years)

Reduce the room thermostat by 1oC

Insulate Roof where possible1,6142,003

£56

Draught proofing - 25% reductionReplace analogue with digital thermostat

Total Annual Use (kWh)

Install low flow shower head

Profl.

1,4791,3071,235

DIY

£62£76

£47

1.3 Summary of heat & hot water energy use & energy reduction actions

-

1,000

2,000

3,000

4,000

5,000

6,000

7,000

Glazing Walls Floor Roof Air / draughts Hot Water

3,415

6,457

1,535 2,171

6,457

4,357

kWh

/ yea

r

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Table E2: All proposed actions ranked by the estimated annual energy savings for heating & hot water at your property

Totals

£19£8

8434

£416

Insulate Roof where possible

1,479

Annual CO2 Saving (kgs)

338272

In addition to the table on the previous page, table E2 shows all of the proposed actions ranked by energy savings.

£62

£47

£21

Internal wall insulation (100mm)£47

Replace / upgrade to double-glazing

1,293

Fill cavity walls

2,003Draught proofing - 25% reduction

13891

200

10,990

Action

1,614Reduce the room thermostat by 1oC

1,307249

£49208

1,853

£56

Energy Reduction (kWh) Annual Saving (£)

The above table is useful as it provides an alternative way of ranking energy reduction opportunities other than purely financially. Those investments that may make substantial sense in terms of energy and carbon dioxide reductions may not necessarily provide the most appropriate financial return. It should be noted that some of these are interdependent and so the energy savings will change as each individual option is implemented. Please call Anahat Energy to discuss this if required.

Lag pipesLag pipes

1,235

501

Replace analogue with digital thermostat

220

£76

541

Install low flow shower head218

817 £31

1.3 Summary of heat & hot water energy use & energy reduction actions

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3,762£492

Table E3: Top 5 actions by financial payback to reduce electrical energy at your property

6.0

The total electrical energy & cost above excludes any electrical cost to heat your property or hot water (accounted for on the previous page.) Figure E2 shows how energy for electricity is used in your property for the top items incl. lighting. This is based on our survey. Table E3 shows the top 5 actions to reduce electrical energy use, ranked by financial payback.

26

Total Annual Use (kWh)

Replace fluorescent lights with low energy

Figure E2: Estimated electrical energy use by type (from on-site survey)

Action

£3

Annual Saving (£)

Total Annual Cost

Energy Reduction (kWh)

Financial Payback (years)

DIY Profl.

1.4 Summary of electrical energy use & energy reduction actions

0 200 400 600 800

1,000 1,200

1,141

365 307 261 256 137 136 61 55 53 51 37 35 11 5 2 1 1

kWh

/ yea

r

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Solar Photovoltaics: Generating Electricity

1.1 £4,950 1,032 £210 £34 17

Solar Thermal: Generating Hot Water

3.5 59% #REF! £281 £219 11

Biomass: Generating Heat & Hot Water

Pellet n/a n/a n/a n/aLog batch n/a n/a n/a n/aWood Chip n/a n/a n/a n/a

Our on-site survey has shown that solar thermal is possible at your property. The table below provides the estimated high level energy potential and returns.

The potential for renewable energy has been assessed at your property estimating the income from UK government subsidies (see later for more information). A summary is shown below of our findings.

Our on-site survey has shown that solar PV is viable at your property. The table below provides the estimated high level energy potential and returns.

Payback (years)

Payback (years)System Type Est. Cost (£

incl. VAT)Storage required

(m3)

Cost (incl. VAT) Net FIT Income

Energy cost savings

% of hot water

Energy / year (kWh)

Roof Area (m2)

It has been determined through on-site analysis and converstations that biomass should not be installed at your property. As such, no calculations have been undertaken.

System size (kWp)

Annual cost savings (with

RHI)

Estimated Cost (incl.

VAT)

Predicted on-site savings

Appropriate

RHI Revenue Payback (years)

1.5 Summary of renewable options at your property

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Today 20 Years£1,441 £2,407£1,040 £1,738

Figure E3: An estimation of how your energy bills may increase over the next 20 years for different energy reduction options.

Action Undertaken

OFGEM, the UK's energy regulator expects energy prices in the UK to increase by 2.6% (on average) every year over the next 20 years. Many observers believe that energy price inflation is more likely to be higher than this - experienced by the recent 10% price hikes by some of the major energy companies. As a result, it is important to understand how your energy bills may be expected to differ if you undertook all of the recommended energy reduction actions versus not doing anything at all. This is shown in figure E3 below, with key numbers in table E4.

% reduction 28%

No energy reductions made

Table E4: Estimated energy bills dependent upon reduction actions taken (excl. renewables)Estimated Energy Bill 20 year (non-

discounted) cost saving

Insulation, draught reduction & top electricity reduction actions £11,006

1.6 Future Energy Bills post energy efficiency actions

£0

£500

£1,000

£1,500

£2,000

£2,500

£3,000

Ann

ual E

nerg

y B

ill

Years from today

Est. heating, hot water & electricity bill - no energy reductions Est. heating, hot water & electricity bill - undertake insulation, draught & electrical reductions

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6.23.5

44%£10,122

Figure E4: CO2 Emissions pre & post proposed energy reduction opportunities

The chart shows how your current CO2 emissions can be reduced by undertaking the proposed top 5 heating and electrical reductions followed by the potential CO2 savings from any possible renewable energy installations.Current CO2 Emissions (t / year)

Possible ReductionPossible Target CO2 Level (t / year)

Projected Cost

1.7 Carbon Dioxide Emissions and Reduction Potential

£0 £1,000 £2,000 £3,000 £4,000 £5,000 £6,000 £7,000

- 1,000 2,000 3,000 4,000 5,000 6,000 7,000

kgs

CO

2 p.

a.

Electricity (kgs, CO2)

Non-electric water (kgs, CO2)

Non-electric heat (kgs, CO2)

Cumulative Cost

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Heating & Hot Water

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Table 1: Main assumptions used in relation to how the client's property is heated

Assumption Value Assumption ValueHeating On 1-Oct Boiler Type GasHeating Off 30-Apr Boiler Efficiency 89%Daily Heating Period 1 start 07:00 Pipe Losses 5% *Daily Heating Period 1 end 09:00 Number of showers / week 14 **Daily Heating Period 2 start 17:00 Length of showers (minutes) 9.75Daily Heating Period 2 end 23:00 9Current Heating Cost (£ / kWh) £0.038 Number of baths / week 0

20 Bath volume (litres) n/a

* Please note that this a pure assumption and could not be determined with any accuracy from our site visit.** The estimated hot water use from hand washing has been calculated in terms of number of showers

The key to a useful energy audit is to determine how your current energy use compares to what should be expected given your location and property type. To do this, we have used the assumptions shown in table 1 which were gathered from conversations during the visit to your property.

Given these assumptions, figure 1 (on the next page) provides a chart of how your energy for heating and hot water should change throughout the year as the outside temperature changes. Table 2 (on the next page) shows you how your bills could be reduced if you decided to reduce the temperature of your property from your current preferred temperature.

Main design temperature (ºC)

Shower flow rate (litres / min)

2.1 Heat & hot water assumptions

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Figure 1: Theoretical energy requirement for heating throughout the year

Table 2: Theoretical energy requirement for heating as the property temperature changes (thermostatic sensitivity.)

Design Temperature (ºC) 15 16 17 18 19 20Theoretical long-term heating / hot water (kWh) 8,727 9,833 11,110 12,405 13,701 15,180Theoretical annual cost (£) £333 £375 £423 £473 £522 £578

84 95 107 119 132 146Heating energy density (kWh / m2)

2.2 Energy for heat / hot water & sensitivity to temp settings

- 500

1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

kWh

/ mon

th

Month

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Table 3: Theoretical energy for heating & hot water versus predicted from current usage patterns

£94815,180

£154

n/an/a

22,067Heat & hot water

Electric HeatersCoal / Coke

Table 3 shows the difference between the energy you used to heat and provide hot water for your property in the last 12 months, and the theoretical long-term (20 year) average amount to provide heat and hot water for your entire property.

Gas Heat & hot water

Not used

Table 3 shows that theoretically (using long-term averages) the property should use less energy to provide heat and hot water than calculated subject to the assumptions in table 1. The assumptions should be clarified if any look subject to error.

24,889

Oil / LPG2,822

Current Year Total

Energy Type

Boost

Comment

n/aElectric Showers

Annual energy use (kWh)

Annual financial cost (£)

£578Long-term theoretical average (20-year)

Wood

Electric Immersion

£794Current Profile

-£370

2.3 Theory verus reality for heat and hot water

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Figure 2: Where energy is used / lost in the property for heating & hot water

Table 4: Breakdown of energy for heating, hot water & cooking

14% 26% 6% 9% 26% 18% 2% 100%

498

Figure 2 provides an overview of how our analysis expects energy to be lost / used throughout your property by area and hot water use, with the % breakdown in table 4. This is based on your actual usage figures. You will note the high level of energy loss expected from air flow / draughts which is based upon the blower door test that was conducted.

External Glazing External RoofExternal WallsDetail

24,8893,415 6,457Annual energy requirement (kWh) 1,535

% of total

Hot WaterAir Ventilation TotalCooking

4,3572,171 6,457

External Floor

2.4 Heating your property & hot water - where does it go?

- 1,000 2,000 3,000 4,000 5,000 6,000 7,000

Glazing Walls Floor Roof Air / draughts

Hot Water

3,415

6,457

1,535 2,171

6,457

4,357

kWh

/ ann

um

Fabric Type

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Table 5: Overview of assumptions used to calculate energy loss and reduction opportunities for walls / doorsCavity w/25mm ins Timber frame Cavity-filled (old) Wood door

0.60 0.50 0.56 2.8030.2 56.2 38.0 5.21,435 2,227 1,660 1,135

Fill cavity Add 100mm0.34 0.2143% 58%£106 £2,531617 1,293£24 £49104 218

Table 6: Overview of range of insulation options for walls ** this is based on mineral fibre, perlite beads could be significantly more expensiveWall Insulation Type Image Description Green options Approximate Cost

Projected Energy Loss p.a

Table 5 shows the assumptions we have made about the different wall and dor types within your property, the possible changes and the potential energy savings as a result. Table 6 provides some high-level information on the different possible actions to insulate different wall types.

Current U-Value

The external render is smoothed prior to the external insulation being affixed to the wall. An external render is then applied to the insulation along with a mesh to enhance the longevity.

E.g. wood fibre board

This can be done for significant discounts in many areas. It can be done for free, yet expect cost of approx. £150 - £200.

E.g. mineral wool made of recycled glass available

Area (m2)

New U-Value% reduction

Possible action

Projected financial savingProjected CO2 saving (kg)

Projected energy savingEstimated professional cost**

Type

Insulating material is blown into the cavity between the bricks / blocks. New materials reduce opportunity for moisture build up and "sagging" of insulation.

Fill Cavity Wall

External Wall Insulation Approx £45-£65 per m2

25mm: £20 / m2 to buy the board. 50mm: £25 / m2 to buy the board. Add another £10 / m2 for prof'l installation to both.

Internal Wall Insulation A frame may be added to the existing internal wall, onto which the internal wall insulation and plasterboard are affixed. The plasterboard is then painted. Alternatively, insulation is stuck directly to the existing wall i.e. dib & dab.

E.g. sheep wool, wood fibre board, cellulose

2.41 Heat energy lost through walls & doors

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Table 7: Overview of assumptions used to calculate energy loss and reduction opportunities for floorsSolid w/tiles Solid w/carpet Solid w/lino

0.41 0.23 0.2822.3 21.0 20.0712 378 445

Table 8: Overview of range of insulation options for floorsFloor Insulation Type Image Description Green options Approximate Cost

TypeCurrent U-Value

Table 7 shows the assumptions we have made about the different floor types within your property, the possible changes and the potential energy savings as a result. Table 8 provides some high-level information on the different possible actions to insulate different floor types.

Estimated professional cost

Possible actionNew U-Value% reduction

Area (m2)

DIY: £3-£10 Professional: £30 - 40 per m2

Projected financial saving


Projected energy saving

Projected CO2 saving (kg)

E.g. sheep wool, celluloseAdd insulation below suspended wooden floors

Floorboards can be lifted if no access is available. Battens are added to the joists and solid / mineral insulation laid upon them. A moisture barrier between the joists and floorboards can help to reduce moisture and draughts.

2.42 Heat energy lost through the floors

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Table 9: Overview of assumptions used to calculate energy loss and reduction opportunities for roofs50mm mineral 100mm flat

0.50 0.31

41.0 22.3

1,626 545 Add 250mm rock

wool

0.1276%£22

1,235

£47

208

Table 10: Overview of range of insulation options for roofsRoof Insulation Type Image Description Green options Approximate Cost

Type

Increasing the existing loft insulation & / or adding to places where it is not currently installed offers one of the best returns. 270mm is the current standard regulation, although you may wish to exceed this.

E.g. sheep wool, cellulose DIY: £3-£10 Professional: £15-£20 per m2

Table 9 shows the assumptions we have made about the different roof types within your property, the possible changes and the potential energy savings as a result. Table 10 provides some high-level information on the different possible actions to insulate different roof types.

E.g. sheep wool, cellulose, wood-fibre

DIY: £25-£35 m2 Professional: £35-£40 m2

Internal wall insulation can be added (as described previously) to an existing roof to provide insulation in areas which have been converted and / or have no access / space for additional insulation.

Internal Wall Insulation


Area (m2)

% reduction

Projected energy saving

Projected financial saving

Add extra loft insulation

Possible action

New U-Value

Estimated DIY cost (£)

Current U-Value


2.43 Heat energy lost through the roof

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Table 11: Overview of assumptions used to calculate energy loss and reduction opportunities for windowsDouble (12mm) Double (6mm) Metal DG Wood SG Wood

1.78 2.58 1.79 4.6011.5 5.6 2.5 0.8

1,615 1,135 358 307 Replace with double

glazing Replace with double

glazing

1.78 1.7931% 61%£838 £127353 188£13 £760 32

Table 12: Overview of range of insulation options for windowsGlazing Insulation Type Image Description Green options Approximate Cost

Replace with triple glazing None available £350 / m2

Table 11 shows the assumptions we have made about the different window types within your property, the possible changes and the potential energy savings as a result. Table 12 provides some high-level information on the different possible actions to insulate different window types.

Type

New U-Value

Area (m2)



£200 / m2, although much more for bespoke conservation grade glazing

Replace with double glazing

Possible action

Singe glazing or old double glazing can be replaced to enhance the heat retention due to better gas in the glazing and improved draught proofing.

Estimated professional cost (£)

Current U-Value

By adding an additional single pane of glass to the existing single glazing, the heat loss can be halved. Using k-glass can help to reflect heat back into the property.

None available

Triple glazing offer the best energy reduction opportunites - yet, at a price.

% reduction

Projected energy savingProjected financial saving

None available

£250 / m2Secondary glaze

2.44 Heat energy lost through the windows

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Table 13: Investments to reduce the heating requirement at the client property

Behaviour Change / Zero Cost Interventions 1,479 £56 immediate

Low Cost Interventions 1,307 £47 £15 £40 0.3 0.9 200 £8 £25 £90 3.3 11.8 501 £19 £50 £350 2.6 18.3 2,003 £76 £150 2.0 1,614 £62 £100 £750 1.6 12.2 0 £0 £0 £0 1,235 £47 £22 £328 0.5 7.0 817 £31 £150 4.8

Higher Cost Interventions

Replace / upgrade to double-glazing 541 £21 £965 46.8Replace / upgrade to triple-glazing

1,293 £49 £1,687 £2,531 34.3 51.4

Date Start Date End Zone 1 Start Zone 1 End Zone 2 Start Zone 2 Endn/a n/a n/a n/a n/a n/a

Lag pipes

Replace analogue with digital thermostatInstall zoned digital thermostat

Insulate Roof where possible

Internal wall insulation (25mm)

Take smaller baths


Priority Action? DIY payback (years)

Profl Payback (years)

Action DIY Cost (£)

Profl Cost (£)

Upgrade boiler (to 90%+ efficient)

Reduce the room thermostat by 1oC

Install radiator reflectors

Draught proofing - 25% reduction

Energy Reduction

(kWh)

Insulate Floors where possible

Install simple digital thermostat

Insulate Walls with 100mm mineral fibre

Add secondary glazing

Install low flow shower head

£0

Fill cavity walls

Proposed Thermostatic ChangesNew date / times

Annual Saving (£)

Change thermostat date / time settings1

Table 13 provides an overview of the key actions that can be taken at your property to reduce the energy demand for heating & hot water.


2.5 Overview of heat / hot water reductions actions

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Figure 3: Results of the 'blower door' depressurisation test

Volume of property (m3) 260.0Internal building envelope (m2) 277Floor area (m2) 104Measured Air change rate at 50Pa 18.8Predicted normal air change rate 0.94% premium / discount to building regs 76%

An on-site blower door test was undertaken at your property to predict the rate of air change. This test allows us to estimate more accurately the energy lost due to draughts and air flow throughout a typical year. Figure 3, below, is a graphical representation of this test at your property.

The data collected on-site provided an air change rate per hour (ACH) at 50 pascals (see below). This was based on the dimensional data also shown below.

Note: The chart above shows the amount of air that mechanically exchanged by the blower door system as the pressure between the inside and outside of the property changes. A line of best fit is then calculated. The key figure for building regulations is the air change at 50 pascals which is then used to estimate the rate of air change at the property for normal pressures.

The air change at 50 pascals (a definition of pressure differential between inside and out) provides an indication of how many times the total air in your property is expected to be exchanged for colder, outside air when there is a relatively significant wind (~20mph.) To convert this to an estimate at normal pressures this is simply divided by 20. The appendix shows how this figure is used to calculate heat loss from air infiltration for the property.

Building regulations determine that new properties built today should have a maximum level of air infiltration based upon their size in order to ensure enough fresh air for breathing and to minimise potential moisture issues. The premium (positive) / discount (negative) to this building regulation is shown above (bottom line) and provides an indication of the potential for reduction.

2.6 Measuring energy loss from draughts in your property

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Electrical Energy Demand

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Figure 4: An overview of how electricity is expected to be used within your property for lighting and appliances

Figure 4 provides an overview of how you are expected to use electricity within your property over a whole year for lighting & the next top 10 areas of use. You can see where you use most of your electricity. It should be noted that while most of the figures are calculated from observed wattages during the site visit, some are estimates. The actual consumption of, for example, a fridge/freezer, can be quite different from the assumed figures.

3.1 Results of on-site electrical audit

0

200

400

600

800

1,000

1,200 1,141

365 307 261 256 137 136

61 55 53 51 37 35 11 5 2 1 1

kWh

/ yea

r

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Table 14a: Estimated electrical use at your property Table 14b: Audit vs. bills% of total

0% 2,914100% 3,762

29%

Table 15: Proposed actions to reduce electricity demand at your property

26 £3 20 6.0

Replace fluorescent lights with low energyReplace halogens with 5w bulbs

Install voltage regulator (220v)Upgrade Fridge / freezer to A-rated

Actual Total (from bills) 3,762

Boil less water (assume 20% less)

3762Appliances on standby 0 Electrical audit (kWh)

Halve time in electric shower

There are various ways to reduce electricity demand. Tables 14a,b & 15 provide levels of standby use, level of detail from audit and the associated energy and financial savings for your own property (if possible.)

Profl Cost (£)

Actual energy (kWh)Difference (%)

Profl Payback (years)

Annual Energy (kWh) Theory versus reality

DIY Cost (£)

Appliances when used

Annual Saving (£)

Electric heat from central boiler

Low / Higher Cost Interventions

Behaviour Change / Zero-Cost

Priority Action? DIY payback (years)Electrical Efficiency Action

Energy Reduction

(kWh)

Switch off when not using (i.e. no standby)

Replace incandescents with low energy

3.2 Reducing the electrical demand

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Renewable Energy Options

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Feed-In TariffThe Feed-In Tariff (FIT) pays people for generating their own "green" electricity. It provides a financial benefit in 3 different ways:

1) Generation Tariff: A payment for all the electricity you produce, even if you use it yourself2) Export Tariff: Additional bonus payments for electricity you export into the grid3) On-Site Savings: A reduction on your standard electricity bill, from using energy you produce yourself

Renewable Heat IncentiveThe Renewable Heat Incentive (RHI) is a new Government-backed measure to incentivise producing renewable heat, paying a fixed price for every unit of heat energy you produce. You could get an additional payment for 'exporting' surplus heat if you are connected to a heat mains. While the Renewable Heat Incentive is similar to the Feed-In Tariffs, there are some important differences. In particular:

1) It will be paid for by the Treasury not by energy users (unlike the FIT) for 20 years.2) A minimal level of energy efficiency for domestic propertys (250mm loft insulation & cavity wall insulation where possible) will be required.3) Residential schemes will not be eligible until Phase 2 in 2012, yet this will cover installations after 15th July 2009.

The assumptions used for each of these can be found in the appendix. All the payments are for a minimum of 20 years (25 years for solar photovoltaics) and increase each year in-line with the Retail Price Index (RPI).

Until 2012, domestic installations will receive an upfront payment of: biomass £950, solar thermal £300, ASHP £850 & GSHP £1250. For biomass & heat pumps this is only possible if properties are off the gas network.

For domestic renewable energy installations there are currently two UK Government incentive schemes that aim to accelerate the take-up of renewable energy by providing financial payments either upfornt or for every unit of energy generated. The tariffs have been introduced by the Government to help increase the level of renewable energy in the UK towards our legally binding target of 15% of total energy from renewables by 2020 (up from under 2% in 2009).These incentive schemes are split between electricity and heat generation. An overview of the key details of each is provided below.

4.1 Renewable Energy Incentives in the UK

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Table 16: Key factors in relation to solar PV at your property

9 165

Our on-site survey has shown that solar PV is viable at your property. The table below provides the estimated high level energy potential and returns.

£21027%Estimated value £34

Max. system size (kWp)

Max system cost (£, ex

VAT)

Max. energy / year (kWh)

Orientation (o

from S)Available area (m2)

% of annual electricity use

FIT Income (incl. maint,

year 1)

On-site savings

Figure 5: Monthly predicted energy generation from the maximum sized solar PV system (if possible) versus average electrical demand

£4,9501.1

Payback (years)

1,032 17

4.2 Solar PV generation analysis for your property

0.0 50.0

100.0 150.0 200.0 250.0 300.0 350.0

kWh

/ mon

th

Predicted energy generation from solar PV (kWh / month) Average electrical demand at your property (kWh / month)

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Solar Thermal (Hot Water) Analysis

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Figure 6: Predicted energy required for hot water versus potential generation 3.5 59%% of annual hot water provided

Our on-site survey has shown that solar thermal is possible at your property. The table below provides the estimated high level energy potential and returns.

Solar collector area (m2)

4.3 Solar thermal generation analysis for your home

-

50

100

150

200

250

300

350

400

kWh

/ mon

th

Month

Predicted hot water requirement (kWh / month) Solar thermal energy generation (kWh / month)

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Table 17: Solar Thermal financial returns under different RHI scenarios

11

Payback (years) IRR (%)

£3,675

Government Incentive Scheme? Estimated system cost (£, ex VAT)

At present all domestic solar thermal installations are incentivised by the UK Government's Renewable Heat Incentive (RHI.) Domestic solar thermal installations are currently expected to receive a premium payment of £300. However, they are not guaranteed to receive an additional generation tariff for every kWh generated which is expected to enter into force in 2012 but is not confirmed. As such, table 17 shows the financial returns associated with a solar thermal installation at the property receiving either a) the premium payment, or b) the premium payment plus the the generation tariff (2012 onwards.)

Energy generated (kWh pa)

Annual RHI Payment (£)

Annual savings (£, incl. maint)

Premium payment (£)

2,571 £281 £219£300Receive premium payment & RHI energy rate 10.2%

It is clear (see paybacks in red shaded area) that current financial returns for solar thermal are not good, yet slightly improved via the RHI.

4.3 Solar thermal analysis - financial returns

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Appendix & Glossary

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Table A1: Current & possible heat loss factors (U-values), incl. areas used for calcsType Area (m2) U-Value New U-ValueWindows

1.78

1.79

Roofs 0.12

Estimating the energy required to heat your property is based upon the building measurements taken during the visit to your property combined with the appropriate "heat loss" factors shown below in table A1.

Replace with double glazing

12mm plasterboard, Rockwool (100mm), Pine Fibreboard (10mm), Air Gap, Felt

22.3

Possible Action

Double Glazed (with frame), Aluminium frame, 5.6 2.58

0.31

Single Glazed Glass (with frame), Pine Wood frame, 0.8 4.60 Replace with double glazing

0.5012mm plasterboard, Rockwool (50mm), Pine Fibreboard (10mm), Air Gap, Felt23mm slate,

Argon double-glazed (with frame), Pine Wood frame, 2.5 1.79

Add 250mm rock wool41.0

Argon double-glazed (with frame), PVC frame, 11.5 1.78Sub-type

5.1 Calculating the theoretical energy for heating your property

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Type Area (m2) U-Value New U-ValueWalls 0.34

0.21

Floors

Table A1: Current & possible heat loss factors (U-values), incl. areas used for calcs (contd.)Possible Action

5.2 2.80

Add 100mm

Sub-type25mm internal wall insulation (+ p/bpard), Brick (Building) (50mm depth), Normal cavity air gap, Brick (Building) (50mm depth), Concrete render

500mm screed125mm Concrete (1:2:4), Carpet (underlay)

21.0 0.23

500mm screed125mm Concrete (1:2:4), Tiles,

500mm screed125mm Concrete (1:2:4), Wood panelling (12mm),

30.2

22.3

12mm plasterboard, 25mm pine fibreboard, Rockwool (50mm), 23mm slate, 12mm plasterboard, Brick (Building) (50mm depth), Cavity Wall Fill,Brick (Building) (50mm depth), Concrete render (30mm),

38.0 0.56

56.2

0.60

0.50

Fill cavity

30mm Wood Door,

0.28

0.41

20.0

5.1 Calculating the theoretical energy for heating your property

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Table A2: Air change assumptions used for the heating calculations at your property

Assumption260.000.940.70

In addition, the energy used to heat your property to your desired temperature is dependent upon the rate of air flow in the property. This is referred to as the air change rate. Table A2 shows the air change rates used to calculate your current theoretical energy use for heating, and the rate used to calculate possible reductions after draught-proofing.

Volume of propertyWhat?

Current air change assumptionPossible reduced air change assumption

m3

changes / hrchanges / hr

5.1 Heat loss from air infiltration

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The energy to heat your hot water from a central heating system is calculated using the equation below

The energy to heat your hot water from electric showers is calculated as: Total energy = ESpower x (Stime / 60) x Sw x 52

For your property, table A3 provides the assumptions that have been used:

Table A3: Assumptions used to calculate the hot water requirementsVariable Unit

kilo Watts

minutes

litres / minuteKJ / kg / oC

litresvolume of bath

Stime

148.5

Sw

From SEDBUK databaseBl

What Assumption Used

Showers / weektime per shower

5%AssumedPipe lossesBoiler efficiency

90%

specific heat capacity of water

89%

baths per weekBw150

Espower Electric shower power rating

9.75

Assumed% of total hot water

0

shower flow rate 94.192SHCw

Sflow

5.1 Calculating the energy to provide your hot water

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Table A4: Heat reduction efficiency assumptions

250.0 £ / m2 £ / m2

150.0 £ / m2 £ / m2

350.0 £ / m2 £ / m2

0.5 £ / m2 13.0 £ / m2

11.0 £ / m2 21.0 £ / m2

0.5 £ / m2 15.0 £ / m2

0.5 £ / m2 8.0 £ / m2

20.0 £ / m3 30.0 £ / m2

0.8 £ / m4 21.0 £ / m2

33 £ / m2

105.6 total (£)0.5 £ / m2 25.0 £ / m2

25.0 £ / m2 40.00 £ / m2

Table A4: Electricity reduction efficiency assumptions

Appliance(s)15 £ / bulb 0.75 kWh / day

Replace Fluorescent with T5s plus adaptor 20 £ / bulb 0.55 kWh / dayReplace Incandescents with low energy 3 £ / bulb

Prof Asumption

Add / replace with triple glazing

Appliance(s)

Add 100mm rock wool

DIY Assumption

Add 200mm rock wool

AssumptionWhat?

Replace halogens with 5W equivalent A-rated fridge / freezer

What? Assumption

A-rated fridge or freezer

Add 50mm internal wall insulation

Add 100mm solid

Add 25mm internal wall insulation

What?

Fill cavity

Add / replace with double galzingAdd secondary glazing to single glazing

n/a

Add 200mm solidAdd 300mm rock woolAdd cork

To calculate the paybacks associated with possible energy efficiency actions at your property, the report uses the cost assumptions shown in table A4.

Add rubber backed carpet

Add 150mm rock wool

n/a

Floor / Roof Insulation

Wall Insulation

Glazing

5.1 Cost assumptions for energy efficiency investments

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Listed in tables A5 is a list of all assumptions used within this analyss that have not already been stated.

Table A5: Assumptions used throughout report for the purposes of energy audit & solar analysis

Solar Thermal Details

Width of roof (m) 4.0Depth of roof (m) 2.5Solar collector efficiency 60%Annual maintenance £30RPI 2.0%Possible RHI (£ / kWh) £0.09

Solar PV Details

£0.131

Depth of roof (m)

RPI

0.0330.210

25%25.02.0%

FIT Export rate (£ / kWh)Deemed export (% of total)On-site use (% of total)Solar maintenance (£ / kWp)

50%

Assumption

Property Details

2.35

n/a

Value

4.0

Assumption

Energy loss through pipesElectricity (£ / kWh)

Value

Av. Heating fuel (£/kWh)Electricity (off-peak, £ / kWh)

Value

2£0.038

Average Room Heght (m)

5%

Floors

Width of roof (m)

FIT Generation rate (£ / kWh)2.5

Assumption

Anahat Energy can provide clarification with regards to any assumption that is required by the client.

5.1 Additional assumptions used for analysis

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Solar photovoltaic cells cannot convert all the sun’s energy into electricity. The efficiency is the rate at which energy is converted to electricity. Efficiency decreases as the temperature of the PV module increases.

Solar PV modules are normally quoted in kilo Watt peaks. The kWh / kWp ratio provides a guide to the amount of energy (in kWhs) that should be produced per kWp installed by a system in a year. For the UK it is typically around 800 -900 kWh / annum / kilo Watt peak.

A UK government indicator that measures the average change from month to month in the prices of goods and services purchased by most households in the United Kingdom.

A new UK government support scheme that pays small generators of electricity for every unit of energy produced. See appendix A1.

A unit of energy equivalent to 1000 watts of power over a period of 1 hour.

Kilo Watt Peak (kWp)

40 4332

Solar PV panel efficiency

Feed-in Tariff

Retail Price Index

Solar photovoltaic

Net Present value (NPV)

Water Saturated (sand, gravel)

A government supported incentive scheme that financially rewards the generation of electricity from technologies such as solar photovoltaics and wind.

A government-funded scheme that is due to be enforced for non-domestic installations as of April 2012 to support the development of heat generating renewable technologies.

The internal rate of return (IRR) is a rate of return used in capital budgeting to measure and compare the profitability of investments. It is the discount rate at which the net present value is zero.

The value today of future cash flows.

Internal Rate of Return (IRR)

Renewable heat Incentive (RHI)

Kilo Watt hour

Kilo Watt hour per kilo watt peak (kWh / kWp)

Feed-In Tariff (FIT)

A measure of the rated power, the electric power produced by a solar photovoltaic module or system, under standard test conditions (STC). Used for standardization and comparing different solar modules.

Photovoltaics (PV) is the field of technology and research related to the application of solar cells for energy by converting sunlight directly into electricity.

5.2 Glossary of Terms

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DISCLAIMERWhilst all reasonable steps have been taken to ensure that the information contained within this report is correct, you should be

aware that the information contained within it may be incomplete, inaccurate or may have become out of date. Accordingly, Anahat Energy Ltd makes no guaranties or representations of any kind as to the content of this report or its accuracy and, to the maximum

extent permitted by law, accepts no liability whatsoever for the same including, without limit, for direct, indirect or consequential loss, business interruption, loss of profits, production, contracts, goodwill or anticipated savings. Any person making use of this report

does so at his or her own risk.

Nothing in this report is intended to be or should be interpreted as an endorsement of, or recommendation for, any supplier, service or product. All prices quoted are for guidance only and do not constitute a formal quotation for the supply of goods or services.

anahat energy enhanced energy audit emma & simonby 4,400 kwhs per year to 15,180 at an annual...

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