enhanced energy audit & renewable options analysis2 key points emerge: i) the thermostatic...

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Prepared forAshburton Futures, MASHFFF Project

AddressThree Bedroom 1970's Detached House

Date20th Feb 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 analysis4.4 Biomass 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

a) Boiler regulationThe home has an oil-fired combination boiler which is over 10 years old. The boiler could not be found on the SEDBUK database of boilers and so an exact efficiency level could not be determined. Given the issues with the heating system (provided by the client), it is estimated that the efficiency is not high and a level of 80% has been utilised for the analysis.

The boiler feeds a radiator system that is simply controlled by:

a) a timer that allows the boiler to come on at 7am and go off at 11pm in the evening, andb) manually-regulated thermostatic regulator valves (TRVs) on each of the radiators.

2 key points emerge:

i) The thermostatic radiator regulation is ill-defined i.e. 1 to 5, &ii) whilst TRVs play a key role in regulating a central heating system, they work simply by altering the flow of hot water to the radiators in response to the air temperature. They are able to reduce hot water flow when the desired temperature is reached, but the boiler will continue to cycle on and off regardless.

1.1 Key Report Messages (1)

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Figure S1: The existing oil boiler which is quite old.We would highly recommend the introduction of an electronic room thermostat to regulate the heating more specifically, communicating directly with the boiler and instructing it to stop firing once the desired room temperature is reached, resulting in greater system efficiencies.

A target temperature of 20ºC should theoretically reduce the amount of energy demanded at the property versus current usage levels.

b) Theory vs. RealityThe client used 22,916 kilo Watt hours (kWh) between 1st January 2011 and 1st January 2012 for heating (22,000kWh of oil and 916kWh from wood). Our analysis indicates that for the property (regulating the temperature at 20ºC Monday – Sunday) a long-term annual average of 19,539 kWh should be expected. In addition, our analysis indicates that reducing the thermostat by 1ºC to 19ºC would save another 2,300 kWhs / annum (£180 per year) before any fabric changes have been made to the property.

A simple electronic thermostat would allow the client to be very specific about the thermal comfort level within the property and allow for more research into the possibility of lowering the temperature.

c) Exposed Pipework & RadiatorsThere are several areas of the property where there are radiators and long lengths of uninsulated pipework on the outside walls. We would recommend that the pipes are insulated and that radiator reflector panels (which are very cheap and simple to install) are fitted behind radiators on outside walls, in order to reflect heat back into the room. This will allow the radiators to do their job more effectively.

d) Upgrading the heating systemThe client noted that the water in the heating system requires re-pressurisation every other day. This indicates significant leakages in the pipework and we would recommend that this is corrected as soon as possible. In addition, upgrading the heating system with a new boiler should be investigated. The increased efficiency levels could save (we estimate) approximately 10% of current energy use.

Figure S2: Example of fabric cracks that exist in the building (this one is above the front door)


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e) Oil procurement & connection to the gas mainsThe cost of oil at the property is estimated at £0.078 / kWh (£0.86 / litre) from the bills provided. This is expensive relative to current market prices in the order of £0.6 / litre or £0.055 / kWh. As such, we would recommend that the client, as a minimum, ensures they analyse alternative purchase possibilities.

In addition, the client noted that there is a gas mains in the main road. According to Wales and West Utilities (who own the network), if it is a standard connection then the cost will be in the region of £600 - £700, but this could be more if the main pipe needs to be extended from where it ends at neighbouring Dolphin Lodge. They would provide a free survey to determine the cost.

Switching to gas could reduce energy costs further to approximately £0.04 / kWh. This would have a significant effect on annual energy costs, with savings of 49% (£842) on heating bills, if compared to the current oil cost of 7.8 pence per kWh, or savings of 33% (£396) if compared to a more competitive oil cost of 6 pence per kWh. Fuel switching should be investigated so that the appropriate boiler type (oil or gas) is chosen when upgraded.

3) Heat Energy Reduction

There are significant opportunities to reduce the energy demand at the property by upgrading the insulation levels. The different options are split by fabric type below:

a. Cavity Walls The building has cavity walls that are believed to be unfilled. We would recommend that a cavity wall insulation company is engaged immediately to determine whether this is the case. For independent advice contact the South West Energy Saving Trust Advice Centre on 0800 512 012 to be referred to a local company for a free survey.

Assuming they are not insulated, filling the cavity walls would reduce the annual energy bul by £480 or approximately 6,000 kWhs / year (27% reduction of total energy use). The cost is typically £150-£200 implying an expected financial payback estimated at under 1 year.

Figure S3: Thermal image of cold air infiltrating through open fireplace

Figure S4: Significant building fabric opening between kitchen and side room


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b. RoofThe roof is insulated with poorly laid 100mm mineral fibre insulation, covered with additional layers in odd spots. Given the evidence of previous animal infestations, the low quality of insulation and need for consistency we would recommend removing all of the existing insulation and replacing it with properly installed 300mm mineral fibre insulation, including above the loft hatch.

This would save, we estimate, just under 1,000 kWhs per annum (or £75 per year), paying back in approximately 1/2 year if done DIY.

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

1) as a result of losses through the building fabric and 2) due to losses through unwanted ventilation.

Through the blower door test, we estimate that approximately 3,300 kWhs of heat (14% of the total) is lost through air infiltration at the property. Obviously some of this is needed for proper ventilation. However, by upgrading the window seals and doors we estimate that significant heat loss can be reduced.

Thermal imaging of the property highlighted several areas of heat loss which could be reduced. Example areas include:

- the front door is coming away from the main building fabric, leaving gaps for cold air to infiltrate- many of the windows have poor draught proofing / seals and let significant amounts of air in- the loft is not properly sealed, allowing cold air to infiltrate- there are gaps in the wall where the utility joins the kitchen where cold air can enter the property.

The largest single source of draughts is potentially the open fireplace. If the walls are insulated, a new energy efficient boiler installed and the fireplace is blocked, there may be less desire for an extra heat source. However, as the fire is a feature of the house that the occupier is particularly keen on, then replacing it with a wood burning stove could be a good alternative.

Figure S5: Cold air (blue) infiltrating through window during blower door test

Figure S6: Cold air (blue) infiltrating around loft hatch


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Figure S8: Solar PV generation profile vs. demand

Furthermore wood burning stoves are in the region of 80% efficient compared to an open fire which is typically 20% efficient – providing more useful heat for the same amount of wood used.

4) Electrical Load Energy Reduction

a. LightingThroughout the property there are numerous high-energy light bulbs. Lighting technology has improved significantly over the past years and low energy, “lumens equivalent” LED lighting is available – especially for the halogens. Halogen lighting accounts for the 2nd highest electrical use at the property after the fridge-freezer. We would recommend contacting a local lighting specialist for more detailed advice.

b. Electrical procurementCurrently the property is on a key meter which requires constant “re-filling” to ensure that there is electricity at the property. The cost is £0.155 / kWh. If the client can move to a normal meter electricity costs could be cut by 20% if the average rate of £0.125 could be achieved.

c. Unaccounted LoadOur electrical audit could only account for 3,500 kWhs out of an annual use of 4,500kWhs. Hence, there is approximately 300 Watts (W) of electrical load (at 8 hours a day) unaccounted for and we would recommend trying to understand this more accurately to determine further electrical energy reduction opportunities. We would strongly recommend that you borrow a current cost meter, (which are available from Ashburton Futures). These are simple to use devices that measure your total electricity consumption in real time and allow you to work out how much power is being consumed by different items, by switching appliances on and off.

5) Energy Generation

There is a south-easterly orientated roof at the property which could be used to generate both electricity (solar photovoltaics) and / or hot water (solar thermal). In addition, a pellet-fired biomass system could also be installed as there is sufficient storage and access. We would not recommend investigating heat pumps due to the inappropriate (radiator) heat distribution system.

Figure S7: Cold air infiltraing through letterbox could be reduced with draught proofing


0.0

100.0

200.0

300.0

400.0

500.0

600.0

kWh

/ mon

th

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

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Figure S9: Area beside property that is suitable for biomass storage / boiler placement.

i) Solar Photovoltaics (PV)The property has large trees in front which have been analysed as potential shading hazards for any solar PV system.

Using a sun path chart and solar PV generation software (PV-Syst) an annual yield of 736 kWh / kilo Watt peak (kWp) is estimated – significantly below the yields for an unshaded system in the order of 900 kWh / kWp. As such, the maximum system size would generate a predicted 1,600 kWhs per year – approximately 30% of current demand.

In investment terms, the maximum system size would provide an internal rate of return (IRR) of only 3.3% with an inflation-adjusted payback of 17 years.

ii) Solar ThermalSolar thermal is also possible at the property and could be integrated into any boiler upgrade with an appropriate thermal store for hot water.

Our analysis (after taking account of shading) indicates that 1.5m2 of solar thermal collector would provide 55% of the annual hot water demand.

Current government incentives do not make this financially viable (35 year payback) due to the additional cost associated with using a combination boiler for solar thermal. If the boiler was upgraded to a systems boiler then the payback could fall to 25 years.

iii) BiomassWe estimate that the property would require a 18kW biomass pellet boiler at a projected cost of approximately £20,000. The theoretical energy consumption would require storage of 4m3 if 2 deliveries were received a year.

Given the current Renewable heat Incentives, it is predicted that an investment in a pellet boiler (at the price above and with a demand as shown) would payback within 8 years, providing an estimated net income / energy cost saving thereafter of £2,600 per year (increasing with RPI). We would recommend that the major energy reduction options are undertaken prior to this investment. If all reduction opportunties are accounted for then the boiler size could be reduced to 13kW, reducing the capital cost, energy input and financial returns.


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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 homes 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 4,577 £730Gas n/a n/aLPG n/a n/aOil 22,000 £1,719

Dimensions & Orientation Wood 916 £50Number of floors 2Average room height 2.4 Main Boiler SystemApprox. floor space (m2) 127.0 Fuel OilApprox. volume (m3) 315.5 Boiler type CombiOrientation (o from S) 150o Boiler power (kW) 26.5Roof pitch (o from horiz.) 30 Boiler efficiency (%) 80.0%

Building FabricType

20th Feb 2012

All double-glazed, poor seals

Ashburton Futures, MASHFFF ProjectDate of Energy AuditClientProperty AddressProperty TypeProperty age

FloorsWallsRoofWindows

1970's

Ashburton, DevonDetached Home

DescriptionSolid floors with lino and carpetCavity-unfilled walls (300mm)100mm in mian roof, rest uninsulated

1.2 Overview of Property

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Figure E1: Estimated energy loss / use by type for heating & hot water22,916£1,769

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

immediate0.4

0.5 7.00.8

1.4 4.9

Fill cavity walls2,3246,272973 £75

Total Annual Use (kWh)

Insulate Roof where possible

£179

Install simple digital thermostatInstall radiator reflectors 240

£261£19

Annual Saving (£)

Total Annual Cost

Energy Reduction (kWh)

Financial Payback (years)

DIYAction

Profl.

Reduce the room thermostat by 1oC

3,378

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.

£484

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

-

2,000

4,000

6,000

8,000

10,000

12,000

Glazing Walls Floor Roof Air / draughts Hot Water

3,594

10,946

1,825 1,609

3,386

1,557

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

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.

Install radiator reflectors

767

240

Fill cavity walls £484

£179

Energy Reduction (kWh) Annual Saving (£)

713 £55450 £35

183115Lag pipes

Upgrade boiler (to 90%+ efficient) 1,947 £150 500597

£19

973

Draught proofing - 25% reduction

6,272Install simple digital thermostat

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

Action

3,378 £261Reduce the room thermostat by 1oC

250£75197

Insulate Roof where possible£59

17,062

62

£1,317

Replace / upgrade to double-glazing

2,324

Annual CO2 Saving (kgs)

1,611868

4,382

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

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4,577£730

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

immediate2.12.5

Total Annual Use (kWh)Total Annual Cost

Energy Reduction (kWh)

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

Action

599£29

Replace halogens with 5w bulbs 714

Financial Payback (years)

DIY

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

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.

£114Upgrade Fridge / freezer to A-rated

181£95

Profl.

1.4 Summary of electrical energy use & energy reduction actions

0 100 200 300 400 500 600 700 800 900

1,000 964 918

794

479 438 317

204 148 110 88 46 26 19 16 8 4

kWh

/ yea

r

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Solar Photovoltaics: Generating Electricity

2.1 £7,807 1,602 £317 £64 17

Solar Thermal: Generating Hot Water

1.5 55% £5,775 £108 £73 36

Biomass: Generating Heat & Hot Water

Pellet £19,106 4.0 £788.3 8Log 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 biomass is a viable option at your property. The table below provides the key storage requirements and estimated cost implications for different biomass types at your property.

System size (kWp)

Estimated Cost (incl.

VAT)

Predicted on-site savings

Payback (years)

System Type

Annual cost savings (with

RHI)

Storage required (m3)

Est. Cost (£ incl. VAT)

RHI Revenue Payback (years)

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.

Roof Area (m2)

Payback (years)

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.

Appropriate Energy cost savings

% of hot water

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

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.

1.5 Summary of renewable options at your property

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Today 20 Years£2,499 £4,176£1,186 £1,982

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

Insulation, draught reduction & top electricity reduction actions

Estimated Energy Bill 20 year cost saving

£36,068

% reduction 53%

No energy reductions made

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.

Table E4: Estimated energy bills dependent upon reduction actions taken

1.6 Future Energy Bills post energy efficiency actions

£0 £500

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

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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8.40.8

90%£40,099

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

Current CO2 Emissions (t / year)

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.

Possible ReductionPossible Target CO2 Level (t / year)

1.7 Carbon Dioxide Emissions and Reduction Potential

£0 £5,000 £10,000 £15,000 £20,000 £25,000 £30,000 £35,000 £40,000 £45,000

- 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000

Cos

t (£)

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 OilHeating Off 30-Apr Boiler Efficiency 80%Daily Heating Period 1 start 07:00 Pipe Losses 5% *Daily Heating Period 1 end 11:00 Number of showers / week 3.5 **Daily Heating Period 2 start 11:00 Length of showers (minutes) 5Daily Heating Period 2 end 23:00 10Current Heating Cost (£ / kWh) £0.077 Number of baths / week 3.5

20 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 as the property temperature changes (thermostatic sensitivity.)

Design Temperature (oC) 15 16 17 18 19 20Theoretical heating / hot water p.a. (kWh) 8,395 10,274 12,568 14,892 17,215 19,539Theoretical annual cost (£) £648 £793 £970 £1,150 £1,329 £1,508

66 81 99 117 136 154Heating 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

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

Long-term theoretical average (20-year) £1,508 -£261

Gas

Electric Showers

916

Current Year Total

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.

22,916

Oil / LPG

Annual energy use (kWh)

Annual financial cost (£)

Comment

n/a

0Current Profile

Wood

Electric Immersion

£0

Energy Type

Heat & hot water

Electric HeatersCoal / Coke

19,539

£50

n/an/a

Boost

£1,769

Not used

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.

22,000 £1,719

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% 48% 8% 7% 15% 7% 0% 100%1,5571,609Annual energy requirement

(kWh)

Total

22,916

Hot WaterAir Ventilation Cooking

3,3863,594

External FloorExternal WallsDetail External Roof

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. Heat loss from draughts is calculated using the results of the blower door test

1,82510,946

External Glazing

0

% of total

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

- 2,000 4,000 6,000 8,000

10,000 12,000

Glazing Walls Floor Roof Air / draughts

Hot Water

3,594

10,946

1,825 1,609 3,386

1,557

kWh

/ ann

um

Fabric Type

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Table 5: Overview of assumptions used to calculate energy loss and reduction opportunities for walls / doorsUnfilled cavity wall

1.70119.89,215

Fill cavity0.5468%£4196,272£4841,611

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

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

Area (m2)

New U-Value% reduction

Possible action

Internal Wall Insulation

E.g. mineral wool made of recycled glass available

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

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

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

Fill Cavity Wall

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 Loss p.a

Projected energy saving

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 floorsCarpet Lino0.36 0.7235.8 29.5575 961

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

Area (m2)




E.g. sheep wool, cellulose

Estimated professional cost

Possible action

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.

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.

TypeCurrent U-Value

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 roofsUtility Roof Main house roof

2.05 0.33

4.7 60.6

439 915 Add 200mm rock

wool Add 200mm rock wool

0.18 0.1391% 63%£3 £33

400 573

£31 £44

103 147

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

Estimated DIY cost (£)

Possible action

New U-Value

% reduction


Projected financial saving

Current U-Value


Projected CO2 saving (kg)

Add extra loft insulation

Area (m2)

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

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.

Type

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 U-PVC

2.3328.83,025

Replace with double glazing

1.7425%

£4,316767£59197

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 / m2Triple glazing offer the best energy reduction opportunites - yet, at a price.

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)


Possible action

Estimated professional cost (£)


Projected energy savingProjected financial saving


None available £200 / m2, although much more for bespoke conservation grade glazing

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 £250 / m2

Area (m2)

Secondary glaze

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

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 2,324 £179 immediate

Low Cost Interventions 240 £19 £25 £90 1.4 4.9 450 £35 £50 £350 1.4 10.1 3,378 £261 £200 0.8 713 £55 £100 £750 1.8 13.6 973 £75 £36 £522 0.5 7.0 6,272 £484 £200 0.4

Higher Cost Interventions 1,947 £150 £2,000 13.3

Replace / upgrade to double-glazing 767 £59 £4,316 72.9Replace / 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

Take smaller baths

Install low flow shower head

Annual Saving (£)

Change thermostat date / time settings1£0

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.

Heating Period

Energy Reduction

(kWh)

Insulate Floors where possible

Install simple digital thermostat

Add secondary glazing

Internal wall insulation (25mm)Internal wall insulation (50mm)

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

Fill cavity walls

Proposed Thermostatic ChangesNew date changed to

Priority Action? DIY payback (years)

Profl Payback (years)

Action DIY Cost (£)

Profl Cost (£)

Upgrade boiler (to 90%+ efficient)

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) 315.5Internal building envelope (m2) 280Floor area (m2) 127Measured Air change rate at 50Pa 11.9Predicted normal air change rate 0.6% premium / discount to building regs 34%

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 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.

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 home 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.

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

0 100 200 300 400 500 600 700 800 900

1,000 964 918

794

479 438 317

204 148 110 88 46 26 19 16 8 4

kWh

/ yea

r

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

4% 4,57796% 4,577

0%

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

181 £29 £0 immediate

714 £114 £285 2.5 599 £95 £200 2.1

Priority Action?

Replace incandescents with low energy

Electric heat from central boiler

Appliances on standby 181 Electrical audit (kWh)

DIY payback (years)Annual Saving (£)

Annual Energy (kWh)

Profl Payback (years)

Electrical Efficiency ActionEnergy

Reduction (kWh)

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 (£)

Appliances when used

Low / Higher Cost Interventions

Behaviour Change / Zero-CostSwitch off when not using (i.e. no standby)

4396

Boil less water (assume 20% less)

Actual Total (from bills) 4,577

Replace fluorescent lights with T5'sReplace halogens with 5w bulbs

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

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 Incentive

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.

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 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).

4.1 Renewable Energy Incentives in the UK

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Table 16: Key factors in relation to solar PV at your propertyMax. system size

(kWp)

Max system cost (£, ex

VAT)

Max. energy / year (kWh)

Orientation (o

from S)Available area (m2)

Estimated value

% of annual electricity use

£64

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

£7,8072

Payback (years)

1,602 17£31735%

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.

17 150o

4.2 Solar PV generation analysis for your property

0.0

100.0

200.0

300.0

400.0

500.0

600.0

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 55%Solar collector area (m2)

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.

% of annual hot water provided

4.3 Solar thermal generation analysis for your home

-

20

40

60

80

100

120

140

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

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.

71£0

£300

£5,775

£5,775Receive premium payment & RHI energy rate 1.9%

Energy generated (kWh pa)

853 £108 £73 36

£36Receive RHI premium payment of £300 ONLY £300 n/a

Government Incentive Scheme?

853

Estimated system cost (£, ex VAT) Annual 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.)

4.3 Solar thermal analysis - financial returns

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Biomass

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Table 10: Key biomass storage requirements & costs to meet your heating & hot water requirements (pre-energy investments)22,916

18 Note: See boiler sizing calculation methodology in appendix.910 Note: Approx. 50 litres per kW of max power required1364320

Table 11: Financial returns associated with different boiler types (pre-reductions)

Note: The cost of any additional radiators is not included in the pricing.

Note: Net energy cost / saving is the difference between your current energy spend and the expected spend on wood for your boiler to generate the theoretical energy calculated for your property. A positive number indicates saving money on energy spend,

n/a n/aWood chip (30% MC)

£19,106n/an/a n/a

PelletLog (30% MC)

Biomass Type

Est. accumulattor pre-reductions (litres)

n/a

Net 1st Yr Energy Cost (-) / Saving (+)

Maintenance Cost (£ p.a.)

n/a

n/a£788.3 £300

n/a

Payback in years (£950 + RHI)

n/a

PelletAnnual volume required (m3)

Biomass Type

Annual energy requirement (kWh)Est. boiler size pre-reductions (kW)

n/a

Property design temperature (oC)

Minimum storage volume required (m3)

Est. accumulattor post-reductions (litres)

Pre-Energy Efficiency Reductions

Est. boiler size post-reductions (kW)

8

Wood chip (30% MC)n/a4.0

Log (30% MC)7.9

Est. System Cost (£, excl VAT)

An appropriate biomass system should be able to provide you with heating and hot water. Our on-site survey has shown that biomass is a viable option at your property. The table below provides the key storage requirements and estimated cost implications for different biomass types at your property.

Estimated annual energy cost

Appropriate?

£981n/an/a

4.4 Biomass Analysis

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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 1.74

Roofs 0.18

0.13

Add 200mm rock wool

Double Glazed (with frame), PVC frame, 28.8 2.33Sub-type

0.33

2.05


12mm plasterboard, Rockwool (100mm), Air Gap, 23mm slate,

60.6

Possible Action

12mm plasterboard, Air Gap, 23mm slate, 4.7

Add 200mm rock wool

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.

5.1 Calculating the theoretical energy for heating your property

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Type Area (m2) U-Value New U-ValueWalls 0.54

Floors

125mm Concrete (1:2:4), Wood panelling (12mm),

Fill cavity

29.5 0.72

0.36

1.70Sub-type Possible Action

125mm Concrete (1:2:4), Carpet with rubber pad,

Brick (Building) (50mm depth), Normal cavity air gap, Brick (Building) (50mm depth), Concrete render (30mm), 12mm plasterboard,

119.8

35.8

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

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

Assumption315.530.600.45 changes / hr

m3

changes / hrCurrent air change assumptionPossible reduced air change assumption

Volume of propertyWhat?

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.

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

litres3.5

shower flow rate 104.192

baths per weekBw

SHCw

Espower Electric shower power rating

5Sw

Stime

3.57

Bl

Sflow

100

What Assumption Used

Showers / weektime per shower

5%AssumedPipe lossesBoiler efficiency

90%

specific heat capacity of water

80%From SEDBUK database

Assumed% of total hot water

volume of bath

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

3.0 £ / m2 13.0 £ / m2

11.0 £ / m2 21.0 £ / m2

5.0 £ / m2 15.0 £ / m2

0.5 £ / m2 8.0 £ / m2

20.0 £ / m3 30.0 £ / m2

0.8 £ / m4 21.0 £ / m2

33 £ / m2

419.2 total (£)20.0 £ / m2 35.0 £ / m2

25.0 £ / m2 40.00 £ / m2

Table A4: Electricity reduction efficiency assumptions

Appliance(s)15 £ / bulb 1 kWh / day

Replace Fluorescent with T5s plus adaptor 20 £ / bulb 0.5 kWh / dayReplace Incandescents with low energy 3 £ / bulb

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

Wall Insulationn/a

Add 200mm solidAdd 300mm rock woolAdd cork

Add 25mm internal wall insulation

Glazing

Floor / Roof Insulation

Appliance(s)

Add 50mm internal wall insulation

What?

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

What? Assumption

A-rated fridge or freezer

Assumption

Add / replace with triple glazing

DIY AssumptionWhat?

Fill cavity

Add / replace with double galzingAdd secondary glazing to single glazing

Add 200mm rock wool

Add rubber backed carpet

Add 150mm rock wool

n/a

Add 100mm rock woolAdd 100mm solid

Prof Asumption

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) 7.7Depth of roof (m) 2.5Solar collector efficiency 60%Annual maintenance £30RPI 2.0%Possible RHI (£ / kWh) £0.09

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

Value

FIT Generation rate (£ / kWh)2.5

Assumption

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)

Energy loss through pipesElectricity (£ / kWh)

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

Value

2£0.077

Average Room Heght (m)

5%

Floors

Width of roof (m)

Value

7.7

Assumption

n/a

Solar PV Details

£0.160

50%

Assumption

Property Details

2.40

5.1 Additional assumptions used for analysis

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The report provided an estimation of the boiler size required for your property. This has been based on the methodology shown below..

9.2 kW 4.7 kWNumber of Showers / Bathrooms 2 2

Density (kg / m3)

Energy Density (kWh / kg) kWh / m3

Cost (£ / tonne) Annual Maintance

650 4.44 2886 £190 £300500 3.33 1665 £154 £300

Wood chip (30% MC) 250 3.33 832.5 £100 £200

0.0790.020

Tier 1 limit (kWh) 23,910 Note: Calculated as full boiler capacity for 15% of the year.

Soil Type

Calculated maximum power required in an hour

Biomass Type

1800 hrs / yr1025

2400 hrs / yr

1320

£0.030

£0.043£0.046

Dry, non-cohesive (sand, gravel)

Log (30% MC)

Tier 1 Payment (£ / kWhth)Tier 2 payment (£ / kWhth)

3360 hrs / yr8

Table A8: Renewable Heat Incentive Payment Assumptions

Table A9: Assumptions used for GSHP calculations

Damp, cohesive (clay, loam)

Pellet

5

Specific Extraction Output (W / m2)

Post Reductions

Boiler Sizing

Implied Energy Cost (£ / kWh)

Boiler Size = [Maximum hourly instantaneous power +(3kW x number of showers / bathrooms)] x 1.2

Table A6: Boiler sizing assumptions used in the formula abovePre Reductions

Table A7: Assumptions used for biomass calculations

5.1 Biomass & GSHP assumptions (if required)

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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)

40 2132

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.

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.

5.2 Glossary of Terms

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Whilst 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.

DISCLAIMER

enhanced energy audit & renewable options analysis2 key points emerge: i) the thermostatic...

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