Renewable energy

• Why install renewable energy?
• Renewable energy technologies
• Grants

Producing your own energy at home is often referred to as On-Site Generation. This is because you are using energy at the point of use, which is in itself efficient because there are no transmission losses. To produce energy at home we use Microgeneration technologies. Renewable Energy is important because it is sustainable. Unlike fossil fuels (gas, coal, oil) there are essentially endless supplies (sun, wind).

Why would you install renewable energy technologies?

People have different reasons for switching to renewable energy. For example, in some remote rural areas of Devon there is no gas supply and perhaps not even an electricity supply. These homes will generally be dependent on expensive energy sources, often brought great distances - a diesel generator for example. This will not apply to people living in Plymouth.

In Plymouth, people have mentioned the following motives:

• They want to 'do their bit' for the environment. Most renewable energy is Clean Energy. Carbon dioxide emissions are low or zero. This makes a major contribution to a desire to reduce your Carbon or Ecological Footprint - your impact on the global ecosystem.
• Renewable energy is 'free'. Once you have purchased technology such as a solar panel or micro-wind turbine, the energy is free so long as the technology keeps working. The value of this free energy increases with time as energy prices rise. Some renewable energy technologies require the purchase of fuel - wood pellets for a stove for example.
• They won't suffer power cuts when everyone else does. This is not the case. If your microgeneration technology is linked to the grid you will suffer a power cut when everyone else does. The exception would be if you installed batteries to store energy from a solar photovoltaic or micro-wind system. However, in the case of thermal systems, such as a solar hot water system or pellet-burning stove, you will benefit from hot water and heating even if there is a failure of the power grid or gas network.
• Microgeneration technologies

There are a number of renewable technologies worthy of consideration by people living in Plymouth. For heating and/or hot water:

• solar thermal - hot water system
• biomass burners - eg wood pellet-burning stove
• ground-source heat pumps

For electricity:

• photovoltaics - solar panels that produce electricity
• micro-wind - small wall-mounted wind turbines

Grants are available towards the cost of all of these.

Note: you may see reference to a microgeneration technology called micro Combined Heat and Power (mCHP). This looks like a boiler and will produce electricity and heating in your home, but uses gas as a fuel and is not therefore renewable.

Tips:

• in a typical home, about three-quarters of energy is used for heating/hot water and one-quarter for electricity. Renewable 'thermal' systems will therefore often meet more of your energy needs.
• to maximise the benefit of your investment in renewable energy, improve your energy efficiency. Use low energy lighting and appliances and fully insulate your home.
• if you want to be 'green' without investing in renewable energy, switch to a 'green tariff' with your electricity supplier. Solar Thermal is by far the most common renewable technology in the housing sector. This is primarily because it is just about cost-effective in an economic 'payback' sense. In other words, it will eventually pay for itself in reduced energy bills. Solar thermal involves installing a panel on your roof and linking this to a hot water cylinder. The panel will meet about 60% of a typical household's hot water needs during a year - more in the summer and less in the winter.
• beware of companies operating in Plymouth who use 'hard sell' tactics and charge high prices. In a typical house you should expect to pay £2,500 to £3,500 for a complete system. Photovoltaics are very expensive. A typical household photovoltaic - or PV - system will cost from about £8,000. This would be for a system with a power rating of 2kWp - 2 kilowatts peak. The 'peak' refers to the maximum power output. Many different PV technologies are available - seek professional advice from a company that installs a variety of different types.
• if you need to replace your roof, this is a good time to consider 'solar shingles' on the southerly elevation. The cost is less if you have to replace the roof anyway!

Micro-Wind turbines are usually attached to a gable end or high up on a wall. The main systems on the market are rated from 1kWp to 2kWp. It is difficult to estimate the proportion of household electricity needs that will be met - but expect about one-fifth over a year. A complete system can be professionally installed from about £1,500.

Tip: if you want to see what a micro-wind turbine looks like, there is one on display at the B&Q Warehouse at Crownhill. They also have a solar thermal panel on display.

Biomass Stoves come in many shapes and sizes, from traditional 'Victorian' style stoves to designer modern stoves that look very space age! Stoves can provide everything from background heating to full central heating with hot water. They use a variety of fuels, such as wood pellets or wood chips or even logs. Before purchasing a biomass stove you should think about where you will obtain fuel - and where you will store it. A full-blown 20kW system to provide heating and hot water for a three-bed house would cost about £5,000. Heat pumps come in three types - ground-source, air-source and water-source. Unless you have a small lake in your back garden you can discount water-source heat pumps! Air-source heat pumps are the least efficient but the easiest to retrofit and can be used in homes that do not have gardens. Ground-source heat pumps are the most common, but you need a fairly sizeable garden to lay the pipes that extract the free heat from about 1.5 metres below the ground. A typical 8kW system will cost from about £7,000 to install.

Tip: heat pumps are a good source of 'low grade' heat. To make the best use of this, consider installing underfloor heating. This will minimise the need for a boost to the heat source, and underfloor heating is probably the most comfortable you will ever experience.

Want to know more? The best independent source of information about all of these technologies is the Energy Saving Trust website.

Grants

Government grants are available from the Low Carbon Buildings Programme (formerly 'Clear Skies'). Grants vary according to the technology you are installing. For example, the grant for a solar hot water system is £400. The grant is not means-tested - everyone is entitled to it. To find out more, visit the Low Carbon Buildings website.

Tip: if you want a grant, you have to use an approved contractor. The Low Carbon Buildings Programme website (above) provides a list of these. Try to use an installer based in the westcountry - help the local economy! Always get a quote from more than one company.

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