Estimating Energy Supply & Demand in Totnes & District

Per capita consumption

Devon CC & (FHSE) 2008 population estimates 23,863 persons in the 16 parishes of Totnes & District.

Per capita consumption
Energy Usage	Annual UK Average Usage Per capita* MWh	All persons Totnes & District MWh
Electricity	5.75	137,212
Personal Transport	10.83	258,436
Heating, Cooling, Cooking	13.51	322,389
All else (services, goods etc)	0.47	11,216
Annual Total (est.)	30.56	729,253**

Per household consumption

Devon CC & (FHSE) 2008 estimates 9,481 households in the 16 parishes of Totnes & District.

Annual Domestic Energy Consumption by end use for an average 3 bed semi-detached house¹

UK energy consumption statistics are divided into 4 sectoral categories, Industry, Domestic, Transport and Services (Includes agriculture). Energy distribution is spread across these sectors in the following proportions (see table below) by DTI / BERR. From this we can calculate estimated sectoral and total consumption based on households in Totnes & District as follows.

Estimated sectoral and total consumption based on households in Totnes & District
Sector	% total energy use	Annual demand all households T & D GWh	Annual demand all households T & D MWh	Annual demand per household MWh
Domestic	30%	212.8	212,848	22.45
Transport	36%	255.4	255,418	26.94
Services	13%	92.3	92,250	9.73
Industry	21%	149.0	148,947	15.71
Total	100%	709.5	709,463	74.83

The household calculations provide the baseline that will be used to assess how the energy needs of  T & D can be met between 2009 to 2030.

Estimating potential for Renewable Energy Supplies in T & D

1. Solar

1a. Photovoltaics (PV)

Available resource – Assumptions:

1. Monocrystalline PV panels will be used (1 kWp=6m²)
2. 1 kWp will produce 750 kWh/y²
3. The cells are orientated between South east through South to South West at an angle of 35 degrees (standard roof pitch) to the horizontal. This implies >96% of the maximum available solar energy will be collected. Ie for all practical purposes 100%
4. No. of dwellings 9,481 of which half will have roof area orientated between South West and South East (= 4,741)
5. Available roof area – assumes average rood area of 9m x 7m = 63m². Assumes a normal straight ridge roof with half facing one way and half the other. 63 ÷ 2 = 31m² less 4m² for solar hot water 27m² available for PV. 4,741 x 27 = 128,007m²
6. Installed capacity @ 6m²/kW = 128,007 ÷ 6 = 21,335 kWp
7. Annual Energy Capture @ 750 kWh/kWp/y = 16,001,250 kWh/y = 16,001 MWH/y

This is expensive and highlights the cost barrier of PV unless support is available from grants. If industry can get costs down to their target figure of 1€/w (~£660/kWp) in 5 years then these costs would come down to £14,081,100

1b. Solar Hot Water (SHW)

Available resource – Assumptions:

1. A 3m² evacuated tube collector will be used. Whilst more expensive they have fewer losses and work in overcast weather. Typically an evacuated tube is about 90% efficient.
2. Solar Hot Water (SHW) will take priority on the roof space because: a) SHW is more efficient so will collect more energy per unit area and is a cheaper technology and b) plumbing runs are more difficult to install and to minimise losses the panel needs to be as close as possible to the hot water tank (PV can be installed around the SHW more easily.)
3. Even an East-West facing roof can collect 84% of the available heat energy, so most dwellings will have access to a roof pitch or vertical surface that could accommodate a viable SHW heater. Although a SHW panel orientated between South East through South to South West at an angle of 35 degrees (standard roof pitch) to the horizontal, will, for all practical purposes, work close to its maximum efficiency.
4. Number of dwellings in T & D= 9,481. Dwellings located in Conservation Areas may be subject to restrictions. But it is assumed that the majority of dwellings will be able to find space somewhere to install a panel. Calculations:

2. Hydropower

2a. Micro-hydro

Hydro power output is the product of ‘head’ (the vertical distance through which the water falls, measured in meters) and the ‘flow’ (the volume of water flowing through the turbine, measured in cubic meters of water per second):

At a given point on a river there will be an area of catchment above it where rainwater runoff is collected. Some of the water will be taken up by plants, trees etc so will evaporate again. The flow available for hydropower will be the net flow less a residual flow that must be left in the main river to ensure the health of aquatic life. Fish protection screens will be needed both above and below the turbine.

Available resource – Assumptions:

1. The ETSU report includes all the larger sites within Totnes & District
2. There will be a number of smaller mill sites such as Rattery Mill, where power could be generated. Experience indicates that many old mill sites that have fallen into disrepair, many have lost their water supply and those that do operate rarely produce more than 10kW. It is unlikely that old mill sites will make a significant contribution to T & D total energy demand, however old mill sites may be able to produce power for on site use.
3. The ETSU report extrapolated figure of 2,226 MWh/y is taken as the potential output for micro hydro

2b. Domestic micro-hydro

2c. Tidal lagoons

The River Dart at Sharpham, below Totnes

An early assessment of the Sharpham site indicates that it may be possible to install a 64 kW turbine which could produce up to 64,000 kWh of energy annually.

2d. Marine Current Turbines

Assessed resource based on per capita share by population in Totnes:

2e. Wave Power

The national potential for this technology is estimated at 4kWh/d per per person by Prof. Mackay³   Assessed resource based on per capita share by population in Totnes:

3 Wind Power

Wind energy can only be farmed where average wind speeds are high enough and will be confined to those areas with an average wind speed of over 7m/s.

3a. Small scale wind

Air contains energy by virtue of its movement and the available power is proportional to the cube of the wind speed (double the wind speed = 8 times the power) and the swept area of the turbine blades. Modern near silent wind turbines have been developed to be mounted like a TV aerial on rooftops. There are also a wide range of intermediate sized ones for use on farmsteads and boats. 2006 costs were in the region of £1,000 / £2,000 for 1 kW / 1.5 kW machines respectively.

The topography around T & D is generally varied, with generally only the outlying T & D parishes having average wind speeds sufficient to make this kind of technology economically viable at domestic level. There exists however the consideration that almost every building could carry a small wind turbine. A very rough estimation is therefore made on the basis that 5% of all households (around 47) in T & D are viable for micro wind.

Estimating that each turbine will generate between 2000 – 3000 kWh/y (& taking the lower figure for increased confidence), 1000 x 2000 = 2,000,000 kWh/y = 2 MWh/y

3b. Large Scale Turbines / Wind farms

The UK has a good wind regime and South Devon a number of areas where, Landscape Designations apart, a significant wind resource could be harnessed. From a purely wind resource perspective, any site that has an average wind speed in excess of 7.5m/s will offer an economically viable site. Up to 5 turbines could be installed per kilometre wind front.

A typical 1.3 MW wind turbine will have a hub height of 50m with 26m blades (52m diameter). For 26m turbine blades the swept area will be 2,2124m²

The total energy capture will be 1,350 x 2,2124 = 2,867,400 kWh/y (2,867 MWh)

3c. Off-shore wind resource

The UK shoreline is surrounded by very windy seas. Off-shore wind and marine current turbines could be installed on the same piles which would share many of the installation costs and the connection cable bringing the energy onshore. The Start Point location off S. Devon has wind energy density of 701-800 W/m².

The resource captured will be constrained by the number of turbines installed and the seabed conditions for installation. A 2 MW wind turbine installed off shore could generate 8,000 MWh/y

The national potential for this technology is estimated as follows:⁴

Assessed resource based on per capita share by population in Totnes:

4 Biomass capacity

The total landholding area for South Hams is 90,650 hectares (ha.), the area of T & D is approximately 21,500 hectares ie 24%. This therefore indicates the following:

4a. Woodlands

Deciduous woodland

This implies that the 586 ha. of deciduous woodland in T & D could sustainably supply (586 x 2.5)

Coniferous woodland

A mature stand of Douglas Fir can yield up to 20 dt/ha/y. Much of this timber will be used for construction, so the available resource for energy will depend upon efficiency of milling and how wastage is reduced. It is assumed that 80% of the timber can be converted into useable timber leaving 20% for energy ie. 4 dt/ha/y is available for energy (169 x 4) = 679 dt/y

This implies that the 169 ha. of coniferous woodland in T & D could sustainably supply (169 x 4)

There are 4 primary ways of using timber: as slab wood, logs, woodchip and pellets:

• A standing tree can be assessed as of timber value, transported to the mill for construction use. The sawdust from the milling process can be used to form pellets and slab wood can be chipped.
• Timber deemed unsuitable for milling can be used as logs or chipped (generally once the moisture level is between 25-35% (<25% timber is too hard, >35% timber starts to compost)
• The brush left in the forest can be of value as faggots or left in situ to rot and benefit biodiversity.
• The energy content of timber is directly related to its moisture content: the drier it is the higher the energy. It is assumed that drying will take place in the air and will not consume more energy. Timber with 60% moisture only has 6GJ/t, timber with 20% moisture has 15GJ/t. 1 tonne of dry timber will replace about 400 litres of oil with a net saving of 1072 kg CO₂⁵
• The use of this finite resource will need to be well managed to ensure best use. It could used in individual wood burning stoves or boilers (~ 70-90% efficient) or used by communities sharing a CHP scheme with a district heat main. With individual usage, the fuel can be used when needed, with a community scheme, although more efficient it will need to be operational to provide constant supply for all. Flexible schemes are advisable.

Assumptions:

1. Some form of cooperative or machinery ring or company can be established that all woodland owners will contract with and agree to maintain all the woodland in T & D
2. That the market and local applications for wood energy can be developed
3. That all woodland can be exploited on a sustainable basis and provide:

4b. Short Rotation Coppice (SRC)

Assumptions:

The average yield from SRC is 8-9dt/ha/y

The DARE report estimated that the then set aside area (in T & D) of 478ha. Would be used for SRC.

4c. Miscanthus

Available Resource – assumptions:

1. All 478 ha of set aside will be planted to Miscanthus
2. Crop yield 15dt/ha/y
3. Energy conversion rate = 15 GJ/dt gives 225 GJ/ha/y (1GJ = 227.8kWh) = 62,505 kWh/ha/y
4. Energy input to establish the crop is a ‘one off’ and is discounted
5. Energy to harvest crop is 630MJ/ha (1MJ=0.2778 kWh) = 175 kWh/ha
6. Energy to transport crop is dependent on distance (say 330 kWh/ha/y)
7. Net energy output; 62,505 less 175 less (say 330) = 62,000 kWh/ha/y
8. 478 x 62,000 = 29,636,000 kWh/y = 29,636 MWh/y

5 Biofuels

5a. Oil seed rape

Available resource – assumptions

• All 478 ha of set aside is used for OSR
• Yields vary but average t/ha
• 478 x 2.9 = 1,386.2 t
• Energy value 37 – 39 GJ/t (say 38 GJ/t)
• Energy yield 1386 x 38 = 52,668 GJ (1 GJ = 277.8kWh) = 14,631,170 kWh = 14,631 MWh
• Energy inputs to grow and harvest the crop = 16,269 =/- 896 MJ/t (say 16.25 GJ/t)
• Therefore the net energy output = 38 – 16.25 = 21.75 GJ/t
• Net energy yield 1386 x 21.75 = 30,145.5 GJ (1 GJ = 277.8 kWh) = 8,374,420 kWh = 8,374 MWh

5b. Bio-ethanol

Available resource (wheat) – assumptions:

• All 478 ha of set aside are available for growing wheat as an energy crop
• Yields 7.74 t/ha
• 478 x 7.74 = 3,700 t
• 1 tonne of wheat gives 0.336m³ of bio-ethanol (336 litres)
• 3,700 x 0.336 = 1,243.2m³ = 1,243,200 litres (L)
• Bio-ethanol has an energy content by volume of 21.1 MJ/L
• 1,243,200 x 21.1 = 26,231,520 MJ (1 MJ = 0.2778 kWh) = 7,287,116.3 kWh = 7,287 MWh

Available resource (Sugar beet) – assumptions:

• All 478 ha of set aside are available for growing sugar beet as an energy crop
• Yields 57.5 t/ha
• 478 x 57.5 = 27,485 t
• 1 tonne of sugar beet gives 0.108m³ of bio-ethanol (108 litres)
• 27,485 x 0.108 = 2,968.38m³ = 2,968,380 litres (L)
• Bio-ethanol has an energy content by volume of 21.1 MJ/L
• 2,968,380 x 21.1 = 62,632,818 MJ (1 MJ = 0.2778 kWh) = 17,399,397 kWh = 17,399 MWh

6 Energy from Waste

The term ‘waste’ needs to be used with caution as nothing is wasted in nature. The by-products from one process are used as the raw material for the next. In this context waste is the collective name we call the organic material we no longer have a use for. It comprises the contents of our dustbins (after recyclables have been separated), kitchen waste, human faeces, animal slurries, animal by-products and food processing wastes.

All organic material degrades quite naturally if oxygen is present, by what is known as an aerobic process and is familiar to us as composting. If oxygen is excluded, by enclosing the process in a sealed chamber, the process is known as anaerobic. The advantage of using an enclosed chamber is that the by-products of organic breakdown (methane) can be captured easily. The methane can then be used as a fuel. If the source material is predominantly wet, a process of anaerobic digestion can be used. If the source material is predominantly dry a process of gasification can be used.

The waste streams considered here are:

• Municipal solid waste (incl. commercial waste arisings)
• Animal slurries
• Sewage sludge

6a. Anaerobic Digestion (AD)

Available Resource – Municipal Waste

Statistics show 70% of waste arisings go to landfill and 30% is recycled or composted

Assumptions:

• South Hams domestic waste (2006 figures) 4,802 t less 11,281 t recycled = 33,521 t
• Energy value = 9.5 GJ/t
• 33,521 t x 9.5 GJ/t = 318,450 GJ
• (9,481 T&D households divided by 34,831 households in DARE report catchment = 0.27%)
• 318,450 GJ x 0.27% = 85,981.5 GJ (1 GJ = 277.8 kWh) = 23,885,661 kWh = 23,886 MWh

Using the Ludlow Experience⁶ and translating their analysis to T&D

Assumptions:

• 9,481 households
• 4.2 kg/household/week
• feedstock = 9,481 x 4.2 x 52 = 2,070,650.4 kg/y = 2,071 tonnes
• Energy value 2,071 x 140 m³/t (bio-gas) = 289,940 m³ x 22 MJ/m³ = 6,378,680 MJ
• (1 MJ = 0.2778 kWh) 6,378,680 x 0.2778 = 1,771,997 kWh = 1,772 MWh

Animal slurries

Based on the DARE report’s assessment of 2004 farm statistics which suggested the following breakdown of farm holdings, these are scaled down for T&D based on the differences in area (The total landholding area for South Hams is 90,650 hectares (ha.), the area of T & D is approximately 21,500 hectares ie 24%). A more accurate assessment could be made based on actual farm data:

Farm Holdings
Farmholding	South Devon	T&D @ 24%
Dairy Holding	56	13
Pig Holding	5	1
Poultry Holding	16	4

To assess the capacity of T&D, a guide is taken from comparison with the Holsworthy Biogas Plant. The Holsworthy biogas plant is capable of producing up to 14,400 MWh/y. The DARE Report assumed that South Devon could carry a similar sized plant, although the figures it was gave (see above) were 56 dairy holdings and the Holsworthy plant was based on just 30 dairy holdings plus food waste. T&D has various farms and a number of small food producers.

The Holsworthy biogas plant is capable of producing up to 14,400 MWh/y. The DARE Report assumed that South Devon could carry a similar sized plant, although the figures it was gave (see above) were 56 dairy holdings and the Holsworthy plant was based on just 30 dairy holdings plus food waste. T&D has various farms and a number of small food producers.

Scaled down to T&D estimated data this could indicate that a similar plant could produce:

Sewage Sludge

Totnes Waste water and sewage treatment plant:

Incoming waste waters:

• Totnes Main sewer 95L/sec maximum
• Sludge from satellite treatment works (~ 20 mile radius)
• Collected contents of septic tanks and cess pits

based on the DARE calculation for CHP plants (see 7) where a 2:1 ratio of heat:power is delivered at CHP plants. This suggests the following potential total energy and portion of heat that could also be utilised at this plant:

6b. Gasification & Pyrolysis

Available Resource – Municipal Waste

Assumptions:

Ref. AD 6a above, (DARE Data for South Devon) extrapolated data for T&D

(9,481 T&D households divided by 34,831 households in DARE report catchment = 0.27%)

The total amount of MSW collected (less recycled) is (33,521 tonnes) 9,051 tonnes Of this (7,607 tonnes) 2,054 tonnes is kitchen waste as used in AD process described previously. This leaves (25,914 tonnes) 6,997 tonnes for gasification.

Available Resource – Commercial Waste

Assumptions:

Ref. AD 6a above, (DARE Data for South Devon) extrapolated data for T&D based on 0.27%

(10,000 tonnes) 2,700 tonnes of mixed waste is collected from all commercial properties in T&D

The amount recycled is not known, but assume same proportion as domestic waste

There will be other feedstocks available such as construction industry waste, abattoir waste etc but data is not available.

6c. Combined Heat & Power (CHP)

Available resource – based on more efficient use of other renewable energy sources
Technology	Para.	Fuel type	Use	MWh assessed 100%	CHP plant @ 90% efficiency	Using CHP 90% efficient MWh/y
						Heat (67%)	Power (33%)
Wood fuel	4a	Woodchip	Biomass CHP boiler	8,934	8,041	5,387	2,654
Miscanthus	4c	Straw	Biomass CHP boiler	29,636	26,672	17,871	8,801
AD (MSW)	6a	Methane	Co-firing	1,772	1,595	1,069	526
AD (animal slurry)	6a	Methane	CHP engine	6,240	5.616	3,763	1,853
AD (sewage sludge)	6a	Methane	CHP engine	1,390	1,251	834	417
Gasification (MSW)	6b	Methane	CHP engine	18,466	16,619	11,135	5,484
Gasification (Comm.)	6b	Methane	CHP engine	4,988	4,489	3,008	1,481
Total				71,426	64,283	43,067	21,216

7  Heat Pumps

Heat pumps need a significant amount of supporting infrastructure and an external energy source. In practice, heat pump technology is best suited to modern new build with high-energy efficiency and hard to heat buildings or buildings which only have grid electricity heating. In this instance, a heat pump could provide up to four times more heat than by conventional electric heating.

Available resource – assumptions

• Half of all properties are suitable for heat pump installations = 9,481 divided by 2 = 4,740
• All properties are fully insulated so heat load is reduced to an average of 6kW per home
• Heat load = 4,740 x 6 = 28,440 kW
• Heating will be needed for 6 months per year (8760 divided by 2 = 4380 hours)
• Using a Coefficient of Performance (COP) of 4 the 28,440 kW could be supplied by 7,110 kW power
• Energy use = 7,110 kW x 4380h = 31,141,800 kWh = 31,142 MWh (31 GWh)
• Renewable energy gain (energy saving) = 28,440 – 7,110 = 21,330 kW x 4380h = 93,425,400 kWh = 93,425 MWh

(Individual household potential gain = 19.71 MWh/y)

The 2006 average cost of installing a heat pump system is between £4,000 – 12,000. This cost could be brought down by a group of installations with bulk purchase etc being carried out.

8 Summary

Summary of Potential Renewable Energy Capture in T & D
Technology	Para.	Energy Capture MWh/y	Energy Capture MWh/y (not countable)	Energy Capture MWh/y not feasible	Co2 saved @ 0.43 kg/kWh
Photovoltaics (PV)	1a	16,001			6.89
Solar Hot Water	1b	23,703			10.19
Micro-hydro – ETSU sites	2a	2,226			0.96
Micro-hydro / non-assessed sites	2a	Not calculated
Micro-hydro (domestic)	2b	94.8			0.04
Tidal Lagoons	2c	64			0.03
Marine Current	2d		78,390		33.71
Wave Energy	2e		34,840		14.98
Small Scale (Micro) Wind	3a	94.81			0.04
Large Wind (2 large turbines)	3b	19,541			8.4
Offshore Wind			418,080		179.77
Woodlands	4a	8,934			3.84
Short Rotation Crop	4b	15,935			6.85
Miscanthus	4c	29,636			12.74
Oil Seed Rape	5a	8,374			3.6
Bio-ethanol (wheat)	5b	7,287			3.13
Bio-ethanol (sugar beet)	5b	17,399			7.48
AD (MSW) Kitchen waste	6a	1,772			0.76
AD Animal Slurry	6a	6,240			2.68
AD Sewage Sludge	6a	1,390			0.6
Gasification (MSW)	6b			18,466
Gasification (Comm.)	6b			4,988
Combined Heat & Power	6c	834*			0.36
Heat Pumps	7	93,425			40.17
Sub-Total (MWh)		203,995.61	531,310	23,454
Total (GWh)		204	531.3	23.4
(Total incl. non countable - GWH)		736.3			316.25

The following assessments can be made for T & D using these estimations:

T & D ability to meet local energy requirement from locally produced renewable energy based on current (100%) usage:

T & D ability to meet local energy requirement from locally produced renewable energy PLUS per capita share of potential off-shore wind and wave renewable energy capture, based on current (100%) usage:

Zero Carbon Britain?

T & D ability to meet local energy requirement from locally produced renewable energy to meet ZCB based on 50% of current usage:

T & D ability to meet local energy requirement from LOCALLY produced renewable energy PLUS per capita share of potential NATIONALLY produced off-shore wind and wave renewable energy capture, based on 50% of current usage:

COUNTDOWN – Generating local Renewable Energy to meet local Needs – Getting there

(calculations based on 2008 baseline demand in T & D 709.5 GWh/yr)

Supplying T & D with 90% of current usage through 10% reduction measures + (10% renewable sources + 80% conventional energy supplies)

Supplying T & D with 80% of current usage through 20% reduction measures + (20% renewable sources + 60% conventional energy supplies)

Supplying T & D with 70% of current usage through 30% reduction measures + (30% renewable sources + 40% conventional energy supplies)

Supplying T & D with 60% of current usage through 40% reduction measures + (40% renewable sources + 20% conventional energy supplies)

Supplying T & D with 50% of current usage through 50% reduction measures + (50% renewable sources + 0% conventional energy supplies)

The following calculations compare the potential for meeting local energy use at the district and household level. The figures can be further calculated to make assessments for farms, parishes etc.

District: Can we meet household use* from power generated on our own houses?

How much of total household domestic usage could be met just using Solar Hot Water (HW) on all houses in T&D?

How much of total household domestic usage could be met by fitting Solar PV & Solar HW on all suitable houses in T&D?

How much of total household domestic usage could be met by fitting Solar PV & Solar HW & Wood fuel burners at all suitable houses in T&D?

How much of total household domestic usage could be met by fitting Solar PV & Solar HW & installing Micro-wind on all suitable houses in T&D?

How much of total household domestic usage could be met by fitting Solar PV & Solar HW & installing Heat Pumps at all suitable houses in T&D?

How much of total household domestic usage could be met by fitting Solar PV & Solar HW & installing Wood fuel & Micro-wind & Heat Pumps at all suitable houses?

Households: Can we meet individual household use* from power generated on our own houses?

Can this be met just fitting Solar Hot Water panels on my house?

Can this be met just fitting Solar PV** & Solar Hot Water panels on my house?

Can this be met fitting Solar PV** & Solar HW panels & installing a Wood fuel burner *** at my house?

Can this be met fitting Solar PV** & Solar HW panels & installing a Micro-wind turbine** on my house?

Can this be met fitting Solar PV** & Solar HW & a Heat Pump** at my house?

Energy Efficiency

It is clear that to generate enough energy to meet current energy demand will require a investment over many years. Reducing our energy demand by investing in energy efficiency is an essential prerequisite to introducing renewable energy and will have a double benefit:

1. A once off investment in energy efficiency will continue to save money indefinitely
2. This will reduce the capital investment needed for renewable energy infrastructure

Energy efficiency covers a very wide range of measures from fitting a condensing boiler to switching off a light. It is estimated that 10% of all energy could be saved by simply changing our behaviour and switching off unwanted appliances.

Space heating is by far the biggest use of domestic energy and this is where the best possibilities of energy efficiency occur.

To what extent can energy efficiency reduce our energy demand?

Annual domestic consumption by end use for an average 3 bedroom semi-detached house
All energy use	80.8GJ	x 277.8	22,446 kWh
Space heating	50.0GJ	x 277.8	13,890
9,481 households		x 22,446	212,810,526 kWh
		total energy use	212.8 GWh
For space heating 9,481 households		x 13,890	131,691,090 kWh
		space heating load	131.7 GWh

Example:

A 3 bedroom semi-detached house measuring 8m x 7m, UPVC double glazed and maintaining an indoor temperature at 21 degrees C whilst the outside temperature is 0 degrees C

Available energy savings assumes:

90% of all dwellings are capable of being fully insulated (9,481 x 90% = 8,533)

Space heating energy consumed by 8,533 dwellings x 13,890 kWh = 118,523,370 kWh

53% energy efficiency saving = 62,817,386

= 62.8 GWh energy reduction through maximising insulation

To what extent can energy efficiency reduce our domestic energy demand?
Total domestic energy demand in T & D	212.8 GWh
Less behaviour changes (10% of total consumption)	21.3 GWh
Less lighting saving (80% of 2% of total consumption)	3.4 GWh
Less insulation measures saving (as above)	62.8 GWh
Total Savings	87.5 GWh
Remaining total energy demand	125.3 GWh

A total saving of 58%

Leave a comment

If you wish to comment on a particular paragraph

and quote the relevant number in your comment.

Name (required)

Mail (will not be published) (required)

Website

Notify me of follow-up comments via email

Subscribe to RSS feed for comments on this page