Solar hot water heater

Solarhot water heaters are the most popular micropower technology in the UK.Solar energy is collected by a panel on a roof, which is connected bypipes to a hot water storage device such as a hot water cylinder ortank.

Asouth facing rooftop is the ideal location for a solar hot water panel(although it is also possible to put a panel on either side of aneast-west facing roof).  The panels depend on radiation rather thandirect sun and so will function on cloudy days as well as sunny.  Therewill be times of the year (and day) when you will need the back up of aboiler to ensure a sufficient supply.

However,the Energy Saving Trust estimates that a solar hot water heater canprovide the average house with almost all of its hot water during thesummer months and about 50% year round. http://www.est.org.uk/myhome/generating/types/solarwater/

Solar hot water heaters heat water for direct use and cannot be connected to central heating radiators.

Thetypical installation cost for a domestic flat plate collector system is£2,000 - £3,000. Evacuated tube systems will cost £3,500 - £4,500.  Grants of up to one third of the cost (to a maximum of £4000) areavailable for solar hot water heaters from SCHRI: http://www.est.org.uk/schri/household/grant.cfm

Somelocal authorities may require you to obtain planning permission,especially if you live in a listed building or conservation area. Please check with your local planning department.

Biomass

Biomassis a term used to describe combustible material of biological origin,which can be burned to generate heat or electricity. It doesn't includefossil fuels, which have taken millions of years to evolve. The CO2released when energy is generated from biomass is balanced by thatabsorbed during the fuel's production, making it carbon neutral.

Fordomestic use, biomass boilers usually burn wood chips, wood pellets orlogs.  Biomass boilers can either be used simply for space heating (ega wood burning stove in a living room) or, preferably, they can have aback boiler fitted to allow them to provide hot water and heatingthrough radiators.

TheEnergy Saving Trust suggests that the following things should be takeninto consideration before installing a biomass boiler:
Fuel: It'simportant to have storage space for the fuel, appropriate access to theboiler for loading and a local fuel supplier.
Flue: The vent material must be specifically designed for wood fuelappliances and there must be sufficient air movement for properoperation of the stove. Chimneys can be fitted with a lined flue.
Regulations: The installation must comply with all safety and buildingregulations (see Part J of the Building Regulations).
Smokeless zone: Wood can only be burnt on exempted appliances, underthe Clean Air Act. This mainly applies to domestic appliances.

Ifthe building is listed or in an area of outstanding natural beauty(AONB), then you will need to check with your Local Authority PlanningDepartment before a flue is fitted.
http://www.est.org.uk/myhome/generating/types/biomass/

Costsof systems vary depending on the size and the fuel used, but a boilerfor space heating generally cost £1500 - £3000 installed.  A biggersystem with a back boiler will cost around £5000 installed.  You shouldalso factor in the ongoing costs of fuel.  This will be cheaper thecloser you are to the fuel source.

Grants of up to one third of the cost (to a maximum of £4000) are available for biomass from SCHRI: http://www.est.org.uk/schri/household/grant.cfm

Solar photovoltaics

Solarphotovoltaic (pv) cells convert the energy from the sun intoelectricity.  They do not need direct sunlight, only daylight to dothis.  Solar pv will work on all roofs, as long as they are not shadedby trees or other buildings, but they perform best on roofs that facesouth, south-east and south-west and that are pitched at an angle of30-40 degrees.  If they are put on a north-facing roof, they will workto around 60% efficiency.

Solarpanels come in a variety of shapes and sizes, for different roofs andapplications.  Some are integrated into tiles, which is worthconsidering if a roof is being replaced.  Installation of solar pvcells must always  be carried out by a trained installer.

Thecost of a system varies according to the size and type of system andits location.  A minimum of 10m2 is advised for a grid connectedsystem.  The Energy Saving Trust estimates that for the averagedomestic system, costs can be around £4,000- £9,000 per kWp installed,with most domestic systems usually between 1.5 and 2 kWp. Solar tilescost more than conventional panels, and panels that are integrated intoa roof are more expensive than those that sit on top.

Grantfunding is available for solar pv, through the Low Carbon BuildingsProgramme. Funding is given up to a maximum of £15,000, subject to anoverall 50% limit of the installed cost (exclusive of VAT). http://www.lowcarbonbuildings.org.uk/micro/solarpv/

Somelocal authorities may require you to obtain planning permission,especially if you live in a listed building or conservation area. Please check with your local planning department.

Ground source heat pump

Groundsource heat pumps (GSHPs)extract heat from the ground and pump it intoa building to provide space heating and to pre-heat domestic hot water.In summer months this process can be reversed to meet the coolingrequirements of a building.

Inthe UK, several metres below the surface, the ground maintains aconstant temperature of 11 to 13°C. In the winter this temperature iswarmer than the air above it. GSHPs are used to extract this heat andtransfer it to a building, where heat is required.

Thereare three elements to a GSHP: the pipes, which are buried under groundeither horizontally or in a borehole, the heat pump and the heatdistribution system.

GSHPscan work with radiator heating systems, but are best suited tounder-floor heating.  They also work best in buildings which are highlyenergy efficient.  It is very important to get expert advice about thesize of the system and the heating needs.

TheEnergy Saving Trust estimate that at a typical 8kW system costs£6,400-£9,600 plus the price of connection to the distribution system.This can vary with property and location.

Grantfunding of up to on third of the cost (to a maximum of £4000) isavailable from the Scottish Community and Household RenewablesInitiative.
http://www.est.org.uk/schri/household/grant.cfm

The Energy Saving Trust also suggests the following points to keep in mind when considering a ground source heat pump:

• The type of heat distribution system. GSHPs can be combined withradiators but under-floor heating is better as it works at a lowertemperature.
  
• Is there space available for a trench or borehole to accommodate a ground loop?
  
• Is the ground suitable for digging a trench or borehole?
  
• Whatfuel is being replaced? If it's electricity, oil, LPG or any otherconventional fossil fuel the payback will be more favourable. Heatpumps are a good option where gas is unavailable.
  
• Wantto be 100% renewable? Buy green electricity, or install solar PV orsome other form of renewable electricity generating system to power thecompressor and pump.
  
• Need a back-up heating system?
  
• Is there also a cooling requirement?
  
• Is the system for a new building development? Combining the installation with other building works can reduce costs.
  
• Can you incorporate insulation measures? Wall, floor and loft insulation will lower your heat demand.

http://www.est.org.uk/myhome/generating/types/groundsource/

It is unlikely that you will need planning permission for a GSHP, but check first with your local planning department.

Micro wind turbine

Microwind turbines generate power by converting kinetic energy from the windinto rotating shaft power, which in turn generates electricity. Turbines vary in size and power and can be mounted on a building orfreestanding.

Thereare a range of models available, from less than 100 watts (W) up to 50kilowatts (kW). Smaller, less than 100 W, micro wind turbines, areoften used to charge 12 volt (V) or 24 V batteries, for use onstand-alone systems. Turbines ranging from 0.6 kW to 50 kW can be usedto provide electricity generation for individual houses and businesses,with rooftop models varying from 0.5 kW to
2.5 kW in size.

Electricityproduced by a wind turbine over a year depends critically on the annualmean wind speed at the site - higher wind speeds produce more energy.Sites located only a hundred metres apart can be significantlydifferent. The ideal site is on a smooth and exposed hill top or riseand clear of any obstructions within a few hundred metres – such astrees or buildings.  However, some systems have been designed withurban use very much in mind, taking into account likely turbulence ofthe wind in these areas.  It is possible to find general information onwind speeds from the Dti wind speed database: http://www.dti.gov.uk/energy/sources/renewables/renewables-explained/wind-energy/page27326.html

However, it is important to survey the wind speed at the specific location that the wind turbine will be used. 

Thecosts of a micro wind turbine vary depending on the size and locationof the turbine but can be from around £1,500 for 1kW rooftop system tobetween £4,000 and £18,000 for fully-installed larger systems of 1.5 –6kW. Ongoing costs should be low, since the wind is free and thesystems are generally low maintenance and just need a check once a year.

Grants of one third of the cost (up to a maximum of £4,000) are available to householders from SCHRI:
http://www.est.org.uk/schri/household/grant.cfm 

Planningpermission is required for micro wind turbines in Scotland, so you mustcontact your local planning department before installation.  Nationalplanning policy guidelines encourage a presumption in favour of smallscale renewable energy technologies. 

Friends of the Earth Scotland's work on micropower is
supported by an Esmee Fairbairn Foundation grant.