Renewable Energy is energy flow that occurs naturally and repeatedly in the environment, such as from the sun, wind and oceans.  Renewable energy is also available from waste products and within the earth.  As electricity is generated from sources that never run out it is a sustainable resource.  With reduced greenhouse gas emissions, renewable energy is cleaner and greener than using fossil fuels.  This technology has moved on in leaps and bounds in the last few years and there are lots of different options open to residents.  Homes can now have a mini wind turbine on their roof and heat their water via solar panels. 

 

There are many types of renewable technology.  They include;

 

Biomass is often called 'bio-energy' or 'bio fuels'. These bio fuels are produced from organic supplies, either directly from plants or indirectly from industrial, commercial, domestic or agricultural products. Bio fuels fall into two main categories:  Woody biomass ( this includes forest products, untreated wood products) and non-woody biomass (animal waste, industrial and biodegradable municipal products from food processing and high energy crops, e.g. rape, sugar cane, maize.  For home-based biomass systems, the fuel usually takes the form of wood pellets, wood chips and wood logs.

 

There are two main ways of using biomass to heat a home. Stand-alone stoves provide space heating for a room, which have an output varying from 6-12 kW.  Some of these models can be adapted to provide hot water.  The other method is through boilers connected to central heating and hot water systems- they generally have an output in excess of 15 kW.

 

Stoves are approximately 80% efficient.   People also like them because they can look attractive in a domestic home.
 

 

It's imperative to have storage space for the fuel and appropriate access to the boiler for loading and a local fuel supplier.

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The vent material must be specifically designed for wood fuel appliances and there must be adequate air movement for proper operation of the stove.

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The installation must act in accordance with all safety and building regulations.  Also, wood can only be burnt on exempted appliances, under the Clean Air Act.  Finally If the building is listed or in an area of outstanding natural beauty, it may be subject to planning  consent

 

The cost of the appliance depends on the type and size of system you choose. However, installation and commissioning costs tend to be fairly fixed. Stand alone room heaters generally cost £1500 - £3000 installed. The cost for boilers varies depending on the fuel choice; a typical 20kiloWatt (average size required for a three-bedroom semi-detached house) pellet boiler would cost around £5000 installed,

Unlike other forms of renewable energy, biomass systems require you to pay for the fuel. Fuel costs generally depend on the distance from your supplier.  The best value from these systems will be gained from those who are off the main gas supply.

 

 

Heat pumps are very familiar to us - fridges and air conditioners are two examples. Ground source heat pumps (GSHP) transfer heat from the ground into a building to provide space heating and, in some cases, to pre-heat domestic hot water- GSHP are like reverse fridges-instead of cooling the space, they heat it instead.

 

 

A typical 8kiloWatt system costs £6,400-£9,600 plus the price of connection to the distribution system. This can vary with property and location.  As it is a more expensive solution, it tends to be less popular than other renewables.  In order to be 100% renewable, you will need to power the system with electric from another renewable source, like a wind turbine or solar system.

 

In the UK we have 40% of Europe's total wind energy. But it's still largely untapped and only 0.5% of our electricity requirements are currently generated by wind power.

 

Wind speed increases with height  (less things to get in its way and dilute it) so it's best to have the turbine set as high as possible.  Small-scale turbines, which fix to the house, are now available.   As with other renewable technologies, planning issues such as visual impact, noise and conservation issues have to be considered and planning permission will be required for any domestic wind turbine.

 

Small-scale wind power is particularly suitable for remote off-grid locations where the usual methods of supply are expensive or impractical. Most small wind turbines generate direct current (DC) electricity. Off-grid systems require battery storage and an inverter to convert DC electricity to AC (alternating current - mains electricity).  You also need a controller to divert power to another useful source (e.g. space and/or water heaters) when the battery is fully charged.

Wind systems can also be installed where there is a grid connection. A special inverter and controller converts DC electricity to AC at a quality and standard acceptable to the grid. No battery storage is required. Any unused or excess electricity can be exported to the grid and sold to the local electricity supply company.

 

 

Systems up to 1kiloWatt will cost anywhere from £1500-£3000 whereas larger systems in the region of 1.5kiloWatt to 6kiloWatt would cost between £4,000 - £18,000 installed. These costs are inclusive of the turbine, mast, inverters, battery storage (if required) and installation, however it's important to remember that costs always vary depending on location and the size and type of system.  Not every house will be suitable for a turbine, factors such as local wind speed are the prime consideration.

 

 

Photovoltaic systems use solar cells to convert the sun‘s rays into electricity. The PV cell consists of one or two layers of a semi conducting material, usually silicon. When light shines on the cell it creates an electric field across the layers, causing electricity to flow.   The stronger the light, the more electricity is generated.
 
PV systems are totally green- they generate no harmful emissions and as such cut 325kilogrammes of carbon dioxide emissions per year..  PV arrays now come in a variety of sizes, shapes and colours, so you can accessorize your house with them!

 

You can use PV systems for a building with a roof or wall that faces within 90 degrees of south, as long as no other buildings or large trees overshadow it.  This is because shadows reduce its effectiveness.   Roofs should also be strong enough to take the system.  Solar PV installations should always be carried out by a trained and experienced installer.  For a list of accredited installers

 

 

For the average domestic system, costs can be around £4,000- £9,000 per kW installed, with most domestic systems usually between 1.5 and 2 kW . Solar tiles cost more than conventional panels, and panels that are integrated into a roof are more expensive than those that sit on top.  

Grid connected systems require very little maintenance, generally limited to ensuring that the panels are kept relatively clean and that shade from trees has not become a problem. The wiring and components of the system should however be checked regularly by a qualified technician.

 

Solar water heating can provide almost all of your hot water during the summer months and about 50% year round.  Before installing a system it is important that you get professional advice.  A competent professional installer should assess your situation and discuss with you the best solar water heating system to meet your needs.

 

If you would like to install a system you will need 2- 4m2 of southeast to southwest facing roof receiving direct sunlight for most of the day. You'll also need space to locate an additional water cylinder if required.

 

For domestic hot water there are three main components: solar panels, a heat transfer system, and a hot water cylinder. Solar panels - or collectors - are fitted to your roof. They collect heat from the sun's radiation. The heat transfer system uses the collected heat to heat water. A hot water cylinder stores the hot water that is heated during the day and supplies it for use later.

 

 

The typical installation cost for a domestic flat plate collector system is £2,000 - £3,000. Evacuated tube systems will cost £3,500 - £4,500.  Solar hot water systems generally come with a 10-year warranty and require very little maintenance. A yearly check by the householder and a more detailed check by a professional installer every 3-5 years should be enough although each system may vary.

 

 

Planning permission will be granted for energy generation development involving the use of renewable sources such as biomass, energy from waste, sewerage sludge, solar power and wind farm schemes providing the impact of the proposal on local land use, amenity, the landscape and sites of ecological, cultural, scientific, historical and archaeological significance is considered acceptable.

 

For more information contact the planning department

 

If you are interested in introducing a renewable energy technology into your home then the low carbon buildings programme can provide grants towards installing these technologies.  So as to make the most of the new technology, it makes sense to ensure your home is as efficient as possible.

 

For further information and to download an application form for low carbon buildings grant funding, see http://www.est.org.uk/myhome/generating/grants/  (this is an external hyperlink)

 

Grants will usually be subject to the installer being accredited by the low carbon buildings programme.  You can also visit the low carbon buildings website  (this is an external hyperlink)