Renewables is certainly a current buzzword.  Alternative energy is a phrase much used, too.  In the eighteenth century demand for wood for the burgeoning metal casting and steam industries was such that coal was an "alternative energy" source!

We now appreciate the consequences of burning fossil fuel and have developed a number of different ways to reduce our dependence on them.

Often this is a partial solution, and Heat Pumps (air or ground source) are a good example of the way in which home heating and hot water can be provided with a substantial reduction in power consumption - in this case electricity.  This isn't the forum for showing how the appliances work; there is a wealth of knowledge out there already.  HWA members will always assist on recommending ways of heating water using Heat Pumps, and it is important that conventional indirect cylinders are not suitable for this duty.

Generally, larger coils, plate heat exchangers or tank in tank designs are needed to get the best from these low out put devices.

Solar thermal is another way to significantly reduce reliance on fossil fuels, usually utilising two coils stacked in one tank with the solar input below the conventional fossil fuel input.  In summer this can provide most of a home's hot water needs and will certainly contribute at other times of the year.

Solid fuel is also coming into its own as a renewable resource in so far as it can be grown as a crop and is considered to be carbon neutral.

Putting a mix of useful energy into a hot water storage unit, whether for hot water only or in conjunction with space heating is a preferred option for many people and it can reap benefits all year long.  However, a word of caution is necessary.  Always consult with appliance manufacturers and hot water cylinder provider to ensure compatibility and design.  Control is a key issue and must be robust to ensure the best efficiencies in multi fuel systems

In addition to the above, new Government initiatives are often aimed to encourage use of such systems and a good place to view them is http://www.gov.org/

Also, more wind farms and other green electricity generating schemes are coming on stream which will help to reduce our collective dependency on fossil fuel.

It is also quite practical to generate electricity on a small scale with PV panels on your roof, a wind generator or a CHP unit where a modified gas boiler will drive a small turbine to generate electricity. The government is prepared to pay householders for the electricity generated and it is proving to be a generous scheme.

There is one thing that cannot be overstated in this introduction.  Storage of some sort is mandatory to harvest these energy types, and hot water storage is the only practical solution to turning the energy into something useful and banking it for when it needs to be used.  As ever, HWA members will be pleased to advise on best practice.