solar water heating, solar power, wind power, wood burning central heating, renewable energy


	Solar water heating Solar water heating is a real option for many thousands of consumers and offers an attractive return on investment combined with high CO2 savings, particularly for consumers who use a lot of hot water and currently rely on oil, electricity or liquefied petroleum gas (LPG). Over time, and if gas prices continue to soar, solar water heating will also hold its own against mains gas boilers for water heating. The technology is highly reliable as there is virtually nothing to go wrong – the pump is the only moving part and rarely causes any problems. It is likely to be a permitted development under local planning guidance. Solar water heating systems are normally fitted to the roof and work in conjunction with a boiler, providing 50 to 70% of domestic hot water requirements over the course of a year. A new cylinder is required and the overall installed system cost is typically between £3,000 and £5,000. Windgenerators Although domestic scale wind turbines are relatively inexpensive there are difficulties associated with this technology. First of all only about 10% of UK postcodes have average wind speeds above the 5.5 metres per second that we believe is necessary for a reasonable performance. Secondly, turbulent air conditions in urban areas may reduce efficiency still further. Finally, with more information about performance becoming available all the time, the actual energy output of the units may turn out to be lower than suppliers’ claims. Wind generators can be roof- or wall-mounted, but we would recommend a pole-mounted system for consumers with big enough gardens. We are aware of a West Midlands housing association that has had problems with wall mounting the generators to older lime-mortared properties. Wind generators are also likely to require planning permission. Small scale wind turbines generate electricity that can be used directly in the home, exported to the national grid or used to charge batteries. The overall installed system cost is typically between £1,500 and £3,000, although introducing batteries into the equation will have an impact on both installation and maintenance costs. Larger turbines, if located Electricity generated by wind turbines attract subsidy under the Feed-in Tariffs. Solar electricity PV cells use semiconductor technology to convert the sun’s energy into electricity. Roof mounted PV is likely to be a permitted development under local planning guidance. A system with the potential to generate 13% of an average household’s electricity over a year would have an installed cost of between £8,000 and £12,000. Solar PV represents an attractive investment at the moment, following the introduction of the feed-in tariffs. 8% to 10% annaul return on investment can be achieved following a PV installation. Micro hydro Not many of us are lucky enough to have a stream running across our property! However many householders with access to flowing water have gained a great sense of personal satisfaction from the installation of micro hydro electric schemes. Micro hydro systems use the flow of water through a small turbine to generate electricity that can be used directly in the home, exported to the national grid or used to charge batteries. The quantity of electricity that can be generated is determined by a combination of the flow rate of the stream and the vertical distance that it falls. So the best sites for installations are often in upland areas or river valleys. The cost of an installed system will vary considerably depending on scale and is likely to be between £10,000 and £25,000. There may also be various regulatory hurdles to overcome! Micro hydro systems are now much more financially viable than ever following the introduction of Feed-in tariffs. Heat pumps As well as being used in fridges, freezers and air conditioning units for chilling, heat pumps are a very effective method of space heating and water heating. Ground source and air source heat pumps both operate on the same scientific principles. Ground source heat pumps concentrate heat from the surrounding ground using buried heat exchange pipes. Air source heat pumps concentrate heat extracted from air surrounding the air source unit, which is attached to the property wall. Another option that may be worth considering in the right situation is the water source heat pump, which concentrates heat from a river, stream or spring welling up at a constant temperature. Heat pumps convert electricity into heat but their ‘magic’ is that they produce several times more heat energy than the electrical energy needed to power them! Ground source units are more efficient and are capable of producing substantially more useful heat than air source units, however potentially disruptive ground works are required making them considerably more expensive in comparison. One housing association we know has been installing ground source heat pumps since 2001. They report that overall costs can be lower than gas, due to the greater reliability of heat pump units compared to condensing gas boilers. The system is described as being ultra reliable with no annual maintenance costs. We believe that ground source heat pumps have a great future in well insulated homes across the UK. We also expect improvements in ground installation technology to drive the market in future years. Although an integral part of air condition systems, air source heat pumps are a relatively new technology for domestic heating in this country. Air source heat pumps have a typical overall installed system cost of between £3,500 and £4,500, and ground source heat pumps of between £10,000 and £13,000. There should not be any planning issues involved with either type. Wood pellet boilers Wood pellet or chip boilers are a great idea! The boiler technology has come on in leaps and bounds, the best models now feature temperature and timer controls, automatic ignition and efficiencies of up to 90%. Wood pellets can be used to provide space and water heating either in a central heating boiler or in a room-heating stove with a back boiler. As they are compact and uniform in shape the pellets have benefits over logs, as with less volume to transport and store fewer deliveries are required. In fact using wood pellets to heat a home can be almost as convenient as using oil. Pellets store well and as they ‘flow’ they can be used in automatic machinery to feed a boiler. The pellets are either gravity fed or screw fed into the appliance as required. Their small size means that they burn well, producing little smoke so that many pellet fuelled heating systems can be operated in smokeless zones. Unfortunately, good quality wood pellets can be expensive: prices need to fall significantly and a good supply chain be developed for these boilers to become a seriously mainstream option in all areas. However, the CO2 savings are truly amazing and in the short to medium term we do expect to see a fall in fuel prices as well as an improvement in availability. A typical installed system costs between £4,500 and £6,000.