FAQs
See our seperate Solar PV FAQ.
Please click on a section name to be taken straight to that section.
- RENEWABLE HEAT INCENTIVES
- FEED-IN TARIFF
- WIND POWER
- SOLAR THERMAL
- GROUND SOURCE HEAT PUMPS
- WOOD FIRED SYSTEMS (BIOMASS)
- AIR SOURCE HEAT PUMPS
RENEWABLE HEAT INCENTIVES
What is the Renewable Heat Incentive?
Due to be launched in April 2011, the Renewable Heat Incentive is planned to last between 10 and 23 years. This will depend on the technology employed. The table below shows the tariff levels currently proposed and are to encourage the purchase and installation of systems that generate heat from renewable sources.
| Small Installations | |||
| Technology | Scale | Tariff (p/kWh) |
Tariff Lifetime |
|---|---|---|---|
| Solid biomass | Up to 45kW | 9 | 15 |
| Biodiesel | Up to 45kW | 6.5 | 15 |
| Biogas on-site combustion | Up to 45kW | 5.5 | 10 |
| Ground source heat pumps | Up to 45kW | 7 | 23 |
| Air source heat pumps | Up to 45kW | 7.5 | 18 |
| Solar thermal | Up to 45kW | 18 | 20 |
| Medium Installations | |||
| Technology | Scale | Tariff (p/kWh) |
Tariff Lifetime |
|---|---|---|---|
| Solid biomass | 45kW – 500kW | 6.5 | 15 |
| Biodiesel | NA | NA | NA |
| Biogas on-site combustion | 45kW – 500kW | 5.5 | 10 |
| Ground source heat pumps | 45kW – 500kW | 5.5 | 20 |
| Air source heat pumps | 45kW – 500kW | 2 | 20 |
| Solar thermal | 45kW – 500kW | 17 | 20 |
FEED-IN TARIFF
What are feed-in tariffs?
Feed-in Tariffs (FITs) became available in Great Britain from of 1st April 2010. Under this scheme energy suppliers make regular payments to householders and communities who generate their own electricity from renewable or low carbon sources such as solar electricity (PV) panels or wind turbines.
The scheme guarantees a minimum payment for all electricity generated by the system, as well as a separate payment for the electricity exported to grid. These payments are in addition to the bill savings made by using the electricity generated on-site.
Once you have a microgeneration technology installed you should experience a monthly reduction in your electricity bill and then receive an income from your Feed-in tariff (clean energy cash back) provider. However, if you have taken out a loan to pay for the installation you will have to make monthly repayments to your loan company. Feed-in tariffs are designed so that the average monthly income from your installation will be significantly greater than your monthly loan repayment (with a 25 year loan).
How does the scheme work?
The scheme covers the following electricity-generating technologies, up to an installation size of 5 Mega Watts:
- Solar electricity (PV) (roof mounted or stand alone)
- Wind turbine (building mounted or free standing)
- Hydroelectricity
- Anaerobic digestion
- Micro combined heat and power (mCHP) (limited to a pilot at this stage)
The tariffs available and the process for receiving them vary, depending on when the technology was installed, and whether the system and the installer were certificated under the MCS* scheme. See below for further details.
You will qualify for the full FIT payments if:
The technology was installed between 15th July 2009 and 31st March 2010 and you transfered to FITs before 1st April; OR
It is installed after 1st April 2010 using an MCS* certificated product and installer;
*What is the Microgeneration Certification Scheme?
The Microgeneration Certification Scheme (MCS) is an independent scheme that certificates microgeneration products under 50kW and installers in accordance with consistent standards. Any commercial or larger scale systems, over 50kW, and all anaerobic digestion installations must apply directly through the Renewables Obligation Order feed-in tariff process for larger installations (ROO-FIT) process as they are not covered by the MCS.
How does FIT** work?
If you are eligible to receive the FIT then you will benefit in 3 ways:
1. Generation tariff – a set rate paid by the energy supplier for each unit (or kWh) of electricity you generate. This rate will change each year for new entrants to the scheme (except for the first 2 years), but once you join you will continue on the same tariff for 20 years, or 25 years in the case of solar electricity (PV).
2. Export tariff - you will receive a further 3p/kWh from your energy supplier for each unit you export back to the electricity grid, that is when it isn’t used on site. The export rate is the same for all technologies.
3. Energy bill savings – you will be making savings on your electricity bills , because generating electricity to power your appliances means you don’t have to buy as much electricity from your energy supplier. The amount you save will vary depending how much of the electricity you use on site.
**source – The Energy Saving Trust (EST). These details may change without notice, may go out of date or be changed by a new government, or new legislation. Letslivegreen.co.uk cannot be held responsible for the figures shown. If in doubt, check for changes on the EST website.
WIND POWER:
How do wind turbines work?
Wind turbines use large blades to catch the wind. When the wind blows the blades turn, driving a turbine which generates electricity. The stronger the wind, the more electricity produced.
What are the benefits of wind powered electricity?
- Harness a plentiful energy source: in the UK we have 40% of Europe's total wind energy.
- Cut your carbon footprint: wind electricity is green, renewable energy and doesn't release any harmful carbon dioxide or other pollutants.
- Cut your electricity bills: wind is free, so once you've paid for the initial installation your electricity costs will be reduced.
- Store electricity for a calm day: if your home is not connected to the National Grid you can store excess electricity in batteries and use it when there is no wind.
- If your small wind system is connected to the National Grid then you can make money by selling any generated electricity back to the electricity supply company.
- From 1st April 2010 you could be eligible to receive cash for each unit of electricity you generate using this technology.
Find out more about the Clean Energy Cashback Scheme.
Is wind electricity suitable for my home?
To tell if a small scale domestic wind turbine is right for you, there are a few key questions to consider:
- Are there any large obstacles like buildings, trees or hills near your home? Small domestic wind turbines work best in exposed locations, without turbulence (usually caused by these types of obstacles).
- Is your home in a windy area? To be effective you need an average windspeed of no less than 5m/s (10mph).
- Is your home located away from the National Grid? Small domestic wind systems are particularly suitable for use in remote locations where mains electricity is unavailable.
- Do you need planning permission? Small domestic wind systems normally do require permission from your local authority, so check before you install a system.
What are the likely costs and savings?
- Costs for a roof mounted micro wind system start at about £1,500. Larger mast mounted systems cost between £11,000 and £19,000, including installation. These provide enough electricity for lighting and appliances in a typical home.
- Savings: Recent monitoring of a range of small domestic wind systems has shown that a well sited 2.5kW turbine could save around £380 a year off electricity bills when some generation is exported, and a saving of around 2.6tonnes of carbon dioxide per year.
- Maintenance checks are necessary every few years, and a well-maintained turbine should last over 20 years. Battery storage life is typically between 6 and 10 years.
How do I know how much energy my wind turbine produces?
A new bi-directional electricity meter is installed which works when you buy (import) and sell (export) electricity. To claim your sale of Renewable Obligation Certificates (ROCs) you will also need a ROC meter, which keeps track of all the energy your turbine generates, irrespective of it being used by you or exported to the grid.
Can I mount a wind turbine on my house?
This is possible (1 kW to 2 kW wind turbines) but as there can be obstacles around the wind turbine it may perform badly, the wind speed may not be high enough. People living under the turbine will be at risk so safety is to be considered. Noise and vibrations in to the structure of the building also needs to be considered.
SOLAR THERMAL:
What is solar thermal?
Solar water heating systems use free heat from the sun to warm domestic hot water. A conventional boiler or immersion heater is then used to make the water hotter, or to provide hot water when solar energy is unavailable.
How do solar water heating systems work?
Solar water heating systems use solar panels, called collectors, fitted to your roof. These collect heat from the sun and use it to warm water which is stored in a hot water cylinder.
There are two types of solar water heating panels, they are evacuated tubes (like in the picture above) and flat plate collectors. Flat plates collectors can be fixed on the roof tiles or integrated into the roof.
A boiler or immersion heater can be used as a back up to heat the water further to reach the temperature set by the cylinders thermostat when the solar water heating system does not reach that temperature. (The cylinder thermostat should be set at 60 degrees centigrade.)
Larger solar panels can also provide energy to heat your home as well - though usually only in the summer months when home heating is unnecessary.
What are the benefits of solar water heating?
- Hot water throughout the year: the system works all year round, though you'll need to heat the water further with a boiler or immersion heater during the winter months.
- Cut your bills: sunlight is free, so once you've paid for the initial installation your hot water costs will be reduced.
- Cut your carbon footprint: solar hot water is a green, renewable heating system and can reduce your carbon dioxide emissions
Is a solar water heating system suitable for my home?
- To tell if solar water heating is right for you, there are a few key questions to consider:
- Do you have a sunny place to put solar panels? You'll need around 5 square metres of roof space which faces east to west through south and receives direct sunlight for the main part of the day. Alternatively, if you do not have a south facing roof and if you have space, you could install two panels, one facing east and one facing west - but this will make installation more costly. The panels don't always have to be mounted on a roof, they can be fixed to a frame on flat roofs.
- Do you have space for a larger, or an extra, hot water cylinder? If a dedicated solar cylinder is not already installed then you will need to replace the existing cylinder, or add a dedicated cylinder with a solar heating coil.
- Is your current boiler compatible with solar water heating? Most conventional boiler and hot water cylinder systems are compatible with solar water heating. If your boiler is a combination boiler (combi) and you don't currently have a hot water tank then a solar hot water system may not be compatible.
- Do you need planning permission? In England most solar water heating systems don't need planning permission, but it is always best to consult your local planning office if you live in a Listed Building, or a building in Conservation Area or World Heritage Site. If you live in Wales, Scotland or Northern Ireland you will need to consult your local authority.
GROUND SOURCE HEAT PUMPS (GSHP):
What are GSHPs?
Ground source heat pumps use pipes buried in the garden to extract heat from the ground. This is usually used to warm water for radiators or underfloor heating systems. It can also be used to pre-heat water before it goes into a more conventional boiler.
Beneath the surface, the ground stays at a constant temperature, so a ground source heat pump can be used throughout the year - even in the middle of winter.
How does a ground source heat pump work?
A ground source heat pump circulates a mixture of water and antifreeze around a loop of pipe - called a ground loop - which is buried in the garden. When the liquid travels around the loop it absorbs heat from the ground - used to heat radiators, underfloor heating systems and even hot water.
The length of the ground loop depends on the size of your home and the amount of heat you need - longer loops can draw more heat from the ground.
Normally the loop is laid flat, or coiled in trenches about two metres deep, but if there is not enough space in your garden you can install a vertical loop to a depth of up to 100 metres.
The efficiency of a ground source heat pump is measured by a coefficient of performance (CoP) - the amount of heat it produces compared to the amount of electricity needed to run it. A typical CoP for a ground source heat pump is around 3.2 without any reductions for the type of distribution system.
What are the benefits of ground source heat pumps?
- Reduce your CO2 emissions: on average a ground source heat pump could save around 540kg of carbon dioxide every year when replacing an oil boiler.
- Eliminate your fuel bills: ground source heat pumps run on electricity, so there's no need to pay for gas, oil or solid fuels to heat your home.
- Cut down on wasted electricity: heating your home with a ground source heat pump is much more efficient than using electric radiators.
Is a ground source heat pump suitable for my home?
- To tell if a ground source heat pump is right for you, there are a few key questions to consider:
- Is your garden suitable for a ground loop? It doesn't have to be particularly large, but the ground needs to be suitable for digging a trench or a borehole and accessible to digging machinery.
- Is your home well insulated? Since ground source heat pumps produce a lower temperature heat than traditional boilers, it's essential that your home is insulated and draught proofed well for the heating system to be effective. It could also make the system cheaper and smaller.
- What fuel will you be replacing? If you're replacing an electric, oil, Liquid Petroleum Gas (LPG) or coal heating system, a ground source heating system will pay for itself quite quickly. If you're replacing a new, more efficient heating system, your savings will be smaller.
- What type of heating system do you want? Underfloor heating systems or warm air heating will work much better than radiator-based systems.
- Is the system intended for a new development? Combining the installation with other building work can reduce the cost of installing the system.
What about the costs and savings?
Costs of installing a typical system range from about £7,000 to £13,000. Running costs for a year, where all hot water and space heating can be provided by the system are likely to be around £650 per year, but will depend on a number of factors - including the size of your home and how well insulated it is.
Savings can be considerable - up to 540kg of CO2 and £160 if you're replacing an oil-fired central heating system.
To reduce your home's CO2 emissions further, consider installing solar electricity or some other form of renewable electricity generating system to power the compressor and pump.
| Fuel Displaced | £ Saving per year | CO2 saving per year |
| Gas | £190 | No saving |
| Electricity | £840 | 6 tonnes |
| Oil | £160 | 540kg |
| Solid | £600 | 5.6 tonnes |
Savings above assume ground source heat pump installed in a detached property which provides 100% of space heating and up to 50% of domestic hot water, the additional 50% is met through an electric heater.
WOOD FIRED SYSTEMS (BIOMASS)
Wood fuelled heating systems generally burn wood pellets, chips or logs to power central heating and hot water boilers or to provide warmth in a single room.
How do wood fuelled heating systems work?
There are two main ways of using wood to heat you home:
A standalone stove burning logs or pellets to heat a single room. Some can also be fitted with a back boiler to provide water heating as well.
A boiler burning pellets, logs or chips connected to a central heating and hot water system.
Log burning stoves and boilers have to be filled with wood by hand. Some pellet and chip burners use automatic fuel feeders which refill them at regular intervals from fuel storage units called hoppers.
A biomass boiler could save you around £470 a year on heating bills
What are the benefits of wood fuel heating?
- A low carbon option: the carbon dioxide emitted when wood fuel is burned is the same amount that was absorbed over the previous months and years as the plant was growing. As long as new plants continue to grow in place of those used for fuel, the process is sustainable. There are some carbon emissions caused by the cultivation, manufacture and transportation of the fuel, but as long as the fuel is sourced locally, these are much lower than the emissions from fossil fuels.
- A good use for waste wood: burning wood can be a convenient means of disposing of waste that might otherwise be sent to a landfill site.
Is a wood fuelled heating system suitable for my home?
To tell if wood fuelled heating is right for you, there are a few key questions to consider:
- Do you have enough space? You'll need a large dry area close to the boiler to store your wood. Ideally this should be close to where the wood is delivered to your home to minimise the distance you have to carry it.
- Do you have a suitable flue? You need a vent which is specifically designed for wood fuel appliances, with sufficient air movement for proper operation of the stove. Your existing chimney can be fitted with a lined flue, which is relatively inexpensive.
- Can you comply with safety and building regulations? If you live in an old or unusual home this may be an issue. For more information, see Part L of the Building Regulations, Northern Ireland and Section 3 of the Technical Handbooks, Scotland
- Do you live in a smokeless zone? If so then wood can only be burnt in certain exempted appliances. http://www.uksmokecontrolareas.co.uk/locations.php
- Do you need planning permission? You need to talk to your local authority if your flue will extend 1m or more above the height of your roof, or your home is in a Conservation Area or World Heritage Site and you plan to install a flue on the principal elevation visible from a road.
What are the costs and savings?
- Costs for a standalone stove are around £3,000 including installation. A typical automatically fed boiler for an average home costs around £9,000 including installation and installing a suitable flue. Manually fed log systems are slightly cheaper.
- Savings in CO2 emissions are significant - up to 9.6 tonnes per year when a wood boiler replaces a solid (coal) fired system.
Fuel savings are less significant, and if you replace a gas heating system with a wood burning system you may end up paying more for your fuel. But if you replace solid or electricity you could save between £170 and £410 per year.
Wood costs often depend on the distance from your home to a wood supplier and whether you can buy and store wood in large quantities. If you have your own supply of wood fuel then this can significantly reduce your costs. Typically, heating and hot water costs for a year will be around £1,000 in a detached property.
AIR SOURCE HEAT PUMPS
What are ASHPs?
Air source heat pumps absorb heat from the outside air. This heat can then be used to warm water for radiators or underfloor heating systems, or to warm the air in your home.
How do air source heat pumps work?
An air source heat pump extracts heat from the outside air in the same way that a fridge extracts heat from its inside. It can extract heat from the air even when the outside temperature is as low as minus 15° C.
There are two main types:
An air-to-water system uses the heat to warm water. Heat pumps heat water to a lower temperature than a standard boiler system would, so they are more suitable for underfloor heating systems than radiator systems.
An air-to-air system produces warm air which is circulated by fans to heat your home.
The efficiency of air source heat pump systems is measured by a coefficient of performance (CoP) - the amount of heat they produce compared to the amount of electricity needed to run them. A typical CoP for an air source heat pump is around 2.5.
What are the benefits of air source heat pumps?
- Reduce your fuel bills: air source heat pumps run on electricity, so there's no need to pay for gas, oil or solid fuels to heat your home.
- Cut down on wasted electricity: heating your home with an air source heat pump is much more efficient than using electric radiators.
- Save space: an air source heat pump system is compact, and requires no storage space for fuel.
Is an air source heat pump suitable for my home?
To tell if an air source heat pump is right for you, there are a few key questions to consider:
- Do you have somewhere to put it? You'll need a place outside your house where a unit can be fitted to a wall or placed on the ground. It will need plenty of space around it to get a good flow of air.
- Is your home well insulated? Since air source heat pumps produce less heat than traditional boilers, it's essential that your home is insulated and draught proofed well for the heating system to be effective.
- What fuel will you be replacing? The system will pay for itself much more quickly if it's replacing an electricity, Liquid Petroleum Gas (LPG) or coal heating system than a gas or oil one.
- What type of heating system do you want? Air source heat pumps are much better at powering underfloor heating systems or warm air heating than radiator-based systems.
- Is the system intended for a new development? Combining the installation with other building work can reduce the cost of installing the system.
Read more about planning permission for renewable energy technologies
What are the costs and savings?
Costs for installing a typical system suitable for a detached home range from about £5,000 to £9,000 including installation. Running costs for space heating and hot water for washing are likely to be around £790 per year. This will vary depending on a number of factors - including the size of your home and how well insulated it is.
Savings can be considerable - up to 5 tonnes of CO2 and £700 per year for a system that replaces an electric heating system.
| Fuel Displaced | £ Saving per year | CO2 saving per year |
| Gas | £50 | No saving |
| Electricity | £700 | 5 tonnes |
| Oil | £20 | No saving |
| Solid | £460 | 4.6 tonnes |
All savings are approximate and are based on an air source heat pump providing 100% of space heating and up to 50% of hot water, with the additional 50% provided by electric heater, in a detached property.
To reduce your home's CO2 emissions further, consider installing solar electricity or some other form of renewable electricity generating system to power the compressor and pump.
