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Prepared forAshburton Futures, MASHFFF Project

AddressMid-Terrace, Two Bed 1960/70's Construction

Date7th 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 has a relatively inefficient gas systems boiler (i.e. with hot water tank) installed (Vokera, Mynute 16e, 79.4% efficiency rating [SEDBUK.]) The boiler could be upgraded to a new efficient (~90%) condensing gas boiler although this would not make economic sense given the very low energy use at the property (see below.)

Heating within the property is regulated through the use of an analogue thermostat set at 17ºC with the heating on between November and the end of February. Thermostatic radiator valves (TRVs) are used on all the necessary radiators. Wood is used to meet the additional heat requirements in an open fireplace in the main living room. This heating strategy is commendable and, combined with the high levels of insulation at the property, leads to a very low annual use for a property of its size. The analogue thermostat could be changed for an electronic thermostat which would:

a) provide an indication of the current temperature in the propertyb) provide greater thermostatic accuracy (to within 0.1ºC)

It is assumed that an electronic thermostat could save up to 10% of current energy use due to greater temperature accuracy – approximately 400 kilo Watt hours (kWh) per year. In addition, the current thermostat position could be changed to a more appropriate place which is more indicative of the lived-in area i.e. living room, and is away from the front door where colder air could unduly affect its regulation i.e. ensure it is on for longer than is necessary. This can be discussed in more detail if required.

1.1 Key Report Messages (1)

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3) Theory vs. Reality

A number of areas should be commended:

a) The property has been very well insulated,b) the thermostatic setting is low at 17ºCc) the heating is only on for an average of 4 months a year (as opposed to a normal 7/8) and d) the boiler itself is off (using the timer) most of the day

The client used an estimated 4,200 kWh of gas for heating (4 months) plus 1,150 kWhs of wood for heating (6 months) per year - a total of 5,350 kWhs.

Using the client-provided assumptions (i.e. 17ºC for 6 months) our analysis suggests that for the property (regulating the temperature at 17ºC Monday – Sunday) a long-term annual average of 2,200 kWh (excl. hot water) should be expected. Clearly 2011 was a very cold winter and this probably accounts for some / most of the discrepancy.

It should be noted, for other properties that have not had the insulative upgrades detailed at the client property, the theoretical energy use would be 48% higher at 17ºC, and 186% higher at 20ºC (for the full 8 month heating period) – showing the impact that target temperature, heating settings and fabric upgrades can have.

4) Heat Energy Reduction

Given the high standard of insulation at the property, there are fewer options to reduce the heat energy demand relative to other properties. However, opportunities still exist and are described below, split by the different building fabric types:

a. RoofThe main roof accounts for only 5% of heat loss at the property predominantly because it has been insulated to just under current building regulations with 250mm of mineral wool. There is little more that can be done at present.

b. WallsThe original cavity walls have been filled and are expected to account for 17% of current heat loss at the property (3rd highest.) There is nothing more that can be done to substantially reduce the heat loss apart from internal insulation which we would not recommend.


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The external wall of the downstairs toilet has been upgraded in 2007 and is assumed to have a relatively low U-value (a measure of the rate of heat loss) as a result of this upgrade. No actions are recommended.

c. GlazingThe glazing is all double-glazed with good levels of draught-proofing apart from the downstairs toilet window (see below.)

No actions are recommended apart from draught-proofing the lower toilet window.

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.)

A blower door test was undertaken to attempt to quantify the level of air-tightness in the property. The fireplace was sealed, yet the existing wall vents (from a gas fire that has since been removed) were left open at the start of the test.

With the vents open, it was impossible to de-pressurise the property to 70Pa (the highest pressure during the test.) After this, the vents were sealed and the test undertaken. The results shown in the report are indicative not of the existing air-tightness but of the potential – equating to 6% above current building regulations. This should be seen as a positive. 2 actions need to be undertaken to achieve this target:

a) Seal the vents: This should be done after consulting with Teign Housing to ensure that this is allowed under current regulations.b) Convert the open fireplace to a wood burner (or equivalent): This would increase the efficiency of extracting heat from the wood (20% to ~80%) and reduce the heat loss from air infiltration. It was possible to see (without the fan extracting air) the way the fire “drew” air out of the room when it was being sealed.

Figure S1: Cold air (blue) infiltrating through living room wall vent

Figure S2: Cold air (blue) infiltrating through poorly sealed loft hatch


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We expect that these actions would have a substantial affect on heat loss from air infiltration and draughts.

In addition, the ground floor toilet was shown to “leak” air through the poorly sealed window. This can be improved cheaply and easily. e. Exposed Pipework & RadiatorsThere is some exposed pipework on external walls which should be insulated to ensure the maximum amount of hot water for heating reaches the radiators – minimising energy losses in the process.

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.

4) Electrical Load & Energy Reduction

The on-site electrical audit predicted a higher annual electricity demand (30% higher) than the estimated electricity bills. The meter has recently been changed so we were unable to determine which was correct. Due to the low estimated use (~ 700kWhs per year) the tariff paid by the client is very high (~21p / kWh) due to the high standing charges (£49 p.a.) As such, we would highly recommend finding a tariff that supports low energy users financially. A "normal" overall tariff of ~ £0.14 / kWh (all in) would save approximately £50 per year in electricity bills.

2 factors are apparent:

i) Fridge / freezer: This is expected to account for 45% of current annual electricity use and could be replaced for a new A-rated version to reduce annual consumption for this appliance by 50%. At an assumed cost of £180 the energy savings would payback within 6 years.ii) Incandescent lights: There are only 3 incandescent lights at the property, but replacing them with low energy equivalents would payback in under a year saving 140 kWhs per year.

In addition, the client is on a key meter and we would highly recommend investigating the conversion to a normal meter with their landlord. This should lead to lower energy costs per unit (see above.)

Figure S3: Cold air (blue) infiltrating through gaps in lower bathroom window frame

Figure S4: Cold air (blue) infiltrating through holes in upper bathroom airing cupboard made for pipe access


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Figure S6: Calculated shading loss diagram (PV-SYST)

Figure S5: Shading perspective to analyse energy generation potential for solar PV (PV-SYST)

5) Energy Generation

The roof of the property is possibly shaded from a chimney, yet is situated such that electricity could be generated using solar photovoltaics (subject to planning.) Solar thermal is also possible yet the current energy use for hot water is minimal. However, an analysis has been undertaken.

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

i) Solar Photovoltaics (PV)The property roof faces 25 degrees west of south and is estimated to have a pitch of 20 degrees from the horizontal. There are shading issues in relation to the house chimney and the raised roof line of the adjacent property. Approximately 18m2 of roof space is available which could allow the installation of up to 2.2 kilo Watt peak (kWp.) This maximum system size would provide a predicted annual energy generation of 1800 kWh per annum (accounting for shading), 76% above the current annual electricity demand.

In investment terms, the maximum system size would provide a rate of return (IRR) of 4.1% with an inflation-adjusted payback of 16 years. In addition, the PV system could be connected to the existing immersion heater to provide hot water at specified power rates (> 900 watts) as opposed to installing a new solar thermal system (see below.)

ii) Solar Thermal (Hot Water)Given that the property is heated using a systems boiler (hot water tank as opposed to a combination boiler) this makes the absolute cost cheaper than would otherwise be the case. We estimate a potential installation cost of £3,500 including a new tank, panels and installation.

To meet the current demand we estimate that 1.5m2 of solar thermal panels would be required, providing just over 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 26 years – not remarkable.


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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 a few 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 659 £139Gas 5,709 £303LPG n/a n/aOil n/a n/a

Dimensions & Orientation Wood 1,152 n/aNumber of floors 2Average room height 2.35 Main Boiler SystemApprox. floor space (m2) 75.0 Fuel GasApprox. volume (m3) 174.9 Boiler type SystemsOrientation (o from S) 205 Boiler power (kW) 16Roof pitch (o from horiz.) 20 Boiler efficiency (%) 79.6%

Building FabricType

Solid (mixed coverings)Mainly cavity filled, one internally insulated250mm in roof, flat to 2007 regs

Property AddressProperty TypeProperty age

FloorsWallsRoofWindows

1964

Ashburton, DevonMid-Terrace, Housing Assoc

Description

Client

Double glazed throughout

Ashburton Futures, MASHFFF ProjectDate of Energy Audit 7th March 2012

1.2 Overview of Property

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Figure E1: Estimated energy loss / use by type for heating & hot water6,891£309

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

5.6 42.26.5

7.2 26.18.7 60.80.0 93.0

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.

Draught proofing - 25% reduction£23

Annual Saving (£)

Total Annual Cost

Energy Reduction (kWh)Action

Financial Payback (years)

£18

Lag pipesUpgrade boiler (to 90%+ efficient)

Install radiator reflectors130366

DIY

Total Annual Use (kWh)

Replace analogue with digital thermostat78

£6£16

£3

Profl.

403522

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

- 200 400 600 800

1,000 1,200 1,400 1,600 1,800

Glazing Walls Floor Roof Air / draughts Hot Water

1,127 1,160 957

362

1,613 1,535

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

403

78

£66

366

Annual CO2 Saving (kgs)

8465

522Draught proofing - 25% reduction

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

1,499

Action

241

130 £6Install radiator reflectors

£18Upgrade boiler (to 90%+ efficient) 59

£3Lag pipes

£16

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.

Replace analogue with digital thermostat

2113

£23

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

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629£133

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

3.8Upgrade Fridge / freezer to A-rated

Annual Saving (£)

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.

223

Financial Payback (years)

DIY

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

Action

£47

Profl.

Total Annual Use (kWh)Total Annual Cost

Energy Reduction (kWh)

1.4 Summary of electrical energy use & energy reduction actions

0 50

100 150 200 250 300 350 400 450 500

482

175 156

63 44 30 28 16 15 3

kWh

/ yea

r

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Solar Photovoltaics: Generating Electricity

2.2 £8,179 1,848 £371 £98 15

Solar Thermal: Generating Hot Water

1.5 61% £3,675 £102 £80 26

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

Roof Area (m2)

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.

Energy cost savings

% of hot water

Energy / year (kWh)Cost (incl. VAT) Net FIT Income

Payback (years)

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.

System Type Est. Cost (£ incl. VAT)

RHI Revenue Payback (years)

Storage required (m3)

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)

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)

Appropriate

Estimated Cost (incl.

VAT)

Predicted on-site savings

1.5 Summary of renewable options at your property

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Today 20 Years£442 £739£331 £554

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

Table E4: Estimated energy bills dependent upon reduction actions taken (excl. renewable incentives)

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.

Action Undertaken

£3,038

% reduction 25%

No energy reductions madeInsulation, draught reduction & top electricity reduction actions

Estimated Energy Bill 20 year (non-discounted) cost

saving

1.6 Future Energy Bills post energy efficiency actions

£0 £100 £200 £300 £400 £500 £600 £700 £800

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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1.50.7

50%£13,859

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

Projected Cost

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)

1.7 Carbon Dioxide Emissions and Reduction Potential

£0 £2,000 £4,000 £6,000 £8,000 £10,000 £12,000 £14,000 £16,000

- 200 400 600 800

1,000 1,200 1,400 1,600

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-Nov Boiler Type GasHeating Off 28-Feb Boiler Efficiency 80%Daily Heating Period 1 start 07:00 Pipe Losses 5% *Daily Heating Period 1 end 09:00 Number of showers / week 1 **Daily Heating Period 2 start 10:00 Length of showers (minutes) 5Daily Heating Period 2 end 22:00 6Current Heating Cost (£ / kWh) £0.044 Number of baths / week 3

17 Bath volume (litres) 100

* 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

Shower flow rate (litres / min)

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)

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 & hot water as the property temperature changes (thermostatic sensitivity.)

Design Temperature (oC) 12 13 14 15 16 17Theoretical long-term heating / hot water (kWh) 2,014 2,305 2,642 2,980 3,318 3,718Theoretical annual cost (£) £89 £102 £117 £131 £146 £164

27 31 35 40 44 50Heating energy density (kWh / m2)

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

-

200

400

600

800

1,000

1,200

1,400

1,600

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

£309

Heat & hot water

Electric HeatersCoal / Coke

3,748

£0

£0

n/a

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.

-£139

Annual energy use (kWh)

Annual financial cost (£)

Gas

Electric Showers0

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.

6,891

£6

Oil / LPG1,152

Current Year Total

30

Energy Type

Hot Water

Main

Comment

Hot Water

5,709Current Profile

Long-term theoretical average (20-year)

Wood

Electric Immersion

£303

£170

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

16% 17% 14% 5% 23% 22% 2% 100%

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 (not accounting for the open fireplace and wall vents.)

138

% of total

External Glazing

External FloorExternal WallsDetail External Roof

6,8911,127 1,160Annual energy requirement (kWh) 957

Hot WaterAir Ventilation TotalCooking

1,535362 1,613

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

-

500

1,000

1,500

2,000

Glazing Walls Floor Roof Air / draughts

Hot Water

1,127 1,160 957

362

1,613 1,535

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-filled Single skin (2007)

0.56 0.4333.7 4.61,048 112

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 Approx £45-£65 per m2

Projected financial savingProjected CO2 saving (kg)

Projected energy saving

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

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

Estimated 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

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 (lino) Solid (carpet) Solid (wood) Solid (rug)

0.44 0.32 0.28 0.4115.3 4.8 2.9 19.3381 86 44 445

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.



Area (m2)

Estimated professional cost

Possible actionNew U-Value% reduction

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

Projected financial savingProjected CO2 saving (kg)

Add 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.

E.g. sheep wool, cellulose

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 roofs250mm internal insul (2007)

0.15 0.29

35.2 4.2

293 69

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

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.

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

Projected CO2 saving (kg)

Area (m2)

% reduction


Projected financial saving

Add extra loft insulation

Possible action

New U-Value

Estimated DIY cost (£)

Current U-Value


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

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 windowsDG-Wood DG-PVC

2.33 2.311.2 7.4162 965

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

Area (m2)

Secondary glaze

Replace with double glazing 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.

Projected CO2 saving (kg)


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

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

Possible action

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

Projected energy savingProjected financial saving

None available

New U-Value% reduction

£250 / m2

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

Low Cost Interventions 78 £3 £25 £90 7.2 26.1 130 £6 £50 £350 8.7 60.8 522 £23 £150 6.5 403 £18 £100 £750 5.6 42.2

Higher Cost Interventions 366 £16 £1,500 93.0

Replace / upgrade to double-glazing

Replace / upgrade to triple-glazing

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

Priority Action? DIY payback (years)

Profl Payback (years)

Action

Upgrade boiler (to 90%+ efficient)

Energy Reduction

(kWh)

Internal wall insulation (25mm)

Take smaller baths

Internal wall insulation (50mm)

Insulate Floors where possible

Install simple digital thermostat

Add secondary glazing

Fill cavity walls

Install zoned digital thermostat

Insulate Roof where possible

Reduce the room thermostat by 1oC

Install radiator reflectorsLag pipes

Replace analogue with digital thermostatDraught proofing - 25% reduction

Install low flow shower head

Proposed Thermostatic ChangesNew date changed toHeating Period

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.

DIY Cost (£)

Profl Cost (£)

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) 174.9Internal building envelope (m2) 215Floor area (m2) 75Measured Air change rate at 50Pa 9.8Predicted normal air change rate 0.49% premium / discount to building regs -20%

The test was completed with the 4 air vents in the wall (kitchen & living room) closed and the open fireplace sealed. This was due to the fact that it was very difficult to reach the appropriate pressure without the vents closed off. As a result, the table above underestimates the current air infiltration rate but is a good indication of the infiltration rate should the vents and fireplace be sealed appropriately. As such, we believe that there are substantial savings to be made by simply closing the vents and / or replacing the open fire with a wood burner (or equivalent.) As discussed on-site, you should speak with your housing provider to ensure that the regulations will allow for the sealing of the vents.

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.

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.

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.

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 50

100 150 200 250 300 350 400 450 500

482

175 156

63 44 30 28 16 15 3

kWh

/ yea

r

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

0% 1,012100% 659

-35%

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

143 £30 £9 0.3 223 £47 £180 3.8

Replace fluorescent lights with low energyReplace halogens with 5w bulbs

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

659Actual Total (from bills) 659

Boil less water (assume 20% less)

Appliances when used0 Electrical audit (kWh)

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

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 (%)

Theory versus reality

DIY Cost (£)

Electric heat from central boiler

Low / Higher Cost Interventions

Priority Action? DIY payback (years)Annual Saving (£)

Annual Energy (kWh)

Profl Payback (years)

Electrical Efficiency ActionEnergy

Reduction (kWh)

Appliances on standby

Behaviour Change / Zero-Cost

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.

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.

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).

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

18 205

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.

Estimated value £98

On-site savings

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

£8,1792.2

Payback (years)

1,848 15£371280%

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)

4.2 Solar PV generation analysis for your property

0.0 50.0

100.0 150.0 200.0 250.0 300.0 350.0 400.0

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 1.5 61%% 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

-

20

40

60

80

100

120

140

160

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 scenariosAnnual RHI Payment (£)

Annual savings (£, incl. maint)

Premium payment (£)

Payback (years) IRR (%)

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)

938 £102 £80 26

£22Receive RHI premium payment of £300 ONLY £300

£3,675

Government Incentive Scheme?

938

Estimated system cost (£, ex VAT)

n/a71£0

Note: Please note that the calculations assume the immersion heater is not used to generate hot water once the solar thermal system has been put in place, hence saving electrical costs as a result.

£300

£3,675

Receive premium payment & RHI energy rate 3.7%

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

Roofs

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.

Double Glazed (with frame), PVC frame, 7.4 2.31

Possible Action

0.29

0.15

12mm plasterboard, Pine Fibreboard (50mm), 50mm Polyurethene (rigid, foam), Air Gap, 23mm slate,

4.2

35.212mm plasterboard, Rockwool (200mm), Rockwool (50mm), Air Gap, 23mm slate,

Double Glazed (with frame), Pine Wood frame, 1.2 2.33Sub-type

5.1 Calculating the theoretical energy for heating your property

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

Floors

Sub-type

125mm Concrete (1:2:4), Wooden Floor, Carpet (rug)

125mm Concrete (1:2:4), Wooden Floor, Lino (5mm)

12mm plasterboard, Brick (Building) (100mm depth), Cavity Wall Fill,Brick (Building) (100mm depth), Concrete render (30mm),

15.3

50mm internal wall insulation (+p/board), Brick (Building) (100mm depth), Concrete render (30mm),

125mm Concrete (1:2:4), Wooden Floor,

0.41

0.5633.7

4.6

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

2.9 0.28

0.44

0.43

125mm Concrete (1:2:4), Wooden Floor, Carpet (synthetic)

4.8 0.32

19.3

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

Assumption174.870.490.37

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.

Current air change assumptionPossible reduced air change assumption

Volume of propertyWhat?

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

17

baths per weekBw

From SEDBUK databaseBl

Sflow

100

What Assumption Used

Showers / weektime per shower

5%AssumedPipe lossesBoiler efficiency

90%

specific heat capacity of water

80%

Assumed% of total hot water

Sw

Espower Electric shower power rating

5

3

shower flow rate 64.192SHCw

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

0.0 total (£)20.0 £ / m2 35.0 £ / m2

25.0 £ / m2 40.00 £ / m2

Table A4: Electricity reduction efficiency assumptions

Appliance(s)15 £ / bulb 0.71 kWh / day

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

Prof Asumption

What?

Replace halogens with 5W equivalent

Add / replace with triple glazing

A-rated fridge / freezer

What? Assumption

A-rated fridge or freezer

AssumptionAppliance(s)

Add 25mm internal wall insulation

Add 200mm rock wool

Add rubber backed carpet

Add 150mm rock wool

n/a

Add 100mm rock wool

DIY Assumption

Add 50mm internal wall insulation

Add 100mm solid

What?

Fill cavity

Add / replace with double galzingAdd secondary glazing to single glazing

Wall Insulation

Glazing

Floor / Roof Insulation

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.

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) 5.0Solar collector efficiency 60%Annual maintenance £30RPI 2.0%Possible RHI (£ / kWh) £0.09

Av. Heating fuel (£/kWh)

50%

Assumption

Property Details

2.352

£0.044

Average Room Heght (m)

5%

Floors

Value

Width of roof (m)

Value

4.0

Assumption

n/a

Solar PV Details

£0.212

RPI

0.0330.210

25%25.02.0%

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

Electricity (off-peak, £ / kWh)

Value

FIT Generation rate (£ / kWh)5.0

Assumption

Depth of roof (m)

Energy loss through pipesElectricity (£ / kWh)

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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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.

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.

32

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)

Kilo Watt Peak (kWp)

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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.

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