All Renewable Energy Ltd

Hot Water From the Sun!

Sunlight remains an inexhaustible energy source. Sustaining the environment, it is available to all and very importantly, it costs nothing. Solar radiation means heat and is one of the best known forms of renewable energy - free, plentiful in supply and available throughout the year. This kind of energy can be effectively harvested by the installation of solar thermal technology.

How Does it Work?

Solar Thermal technology is a clean, safe and highly effective means of utilising renewable energy from the sun to warm domestic hot water. The basic principle is very simple:
If you unroll a garden hose on the ground and leave it exposed to the radiant heat of the sun, in a short time the water in the hose will become warm. Solar thermal collectors work in very much the same way but much more efficiently.
Usually, but not exclusively, roof-mounted solar collectors will be connected to one of the coils of a twin-coil cylinder, using a sealed circuit containing a special antifreeze mix - typically a glycol/water solution. This fluid not only withstands the high temperatures of a summer day, but also will not freeze in temperatures down to -25^oC. The fluid in the collectors is exposed to and heated by the sun's energy, then this hot fluid is pumped through the system to the hot water tank. Most conventional boilers, combi-boilers and hot water cylinder systems are compatible with solar water heating, so there's no problem.

Choosing the Right Solar Thermal Collector

There are two types of collectors used for solar water heating applications: Flat Plate Collectors and Evacuated Tube Collectors.

Flat Plate Collectors can be described most simply as plates of heat-absorbent material to be mounted in a sunny spot. The collector absorbs heat from the sun and then transfers that heat into the fluid circulating around the system.

Evacuated Tube Collectors are panels combining individual tubes with fluid circulating through them, absorbing the sun's heat.
For increased efficiency, Evacuated Tube Collectors feature a highly reflective, weather-proof CPC (Compound Parabolic Concentrator) reflector, fitted behind each evacuated tube. The special, geometric design of the reflector ensures that both direct and diffused sunlight falls onto the absorber even when the angle of the sun is sometimes not ideal. (See image above)

This considerably improves the energy yield.

All Renewable Energy Ltd. recommend Evacuated Tube Collectors.

This type of solar collector is, in our opinion more efficient than the conventional Flat Plate Collector. They are also out-performing others consistently in the colder, cloudy and windy conditions typical in the UK.

In our experience, Evacuated Tube Solar Collectors are, on average 30% more efficient than Flat Plate Collectors!

Is Solar Thermal Suitable for My Home?

There is a common misconception that solar energy systems can work only in conditions of bright sunshine with high temperatures and are therefore unsuited to the British climate. Many believe that solar panels work only in the summer months. However, this type of free energy is available throughout the year. Our recommended solar thermal systems function in any sort of light conditions. They will perform best on cloudless, bright, sunny days, but will also achieve near optimal standards in diffuse or overcast conditions.

Each system uses a heat collector, mounted on the roof in a south-facing direction so that the heat-transfer fluid is heated by the sun. During the summer it can raise the temperature of water to boiling point and so has temperature-limiting features built in to prevent this. During the winter the system naturally performs to a lesser degree due to the reduced available sunlight. Nevertheless, the contribution from solar thermal can still be substantial, ensuring significant savings on your winter fuel bills. Remember, the energy required to raise a body of water from 1ºC to 2 ºC is the same as raising it from 99 ºC to 100 ºC.

The Benefits of Solar Thermal Water Heating

• Enjoy 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 Carbon Footprint: Solar thermal is a green, renewable heating system and can reduce your CO₂(carbon dioxide) emissions.

• Receive Money, (normally tax-exempt for domestic owner-occupiers), From the RHPP (Renewable Heat Premium Payment) & RHI (Renewable Heat Incentive) Schemes With MCS Certified System: See below.

• Cut Your Bills: Sunlight is free, so once you've paid for the initial installation your hot water costs will be significantly reduced thereafter.

• Reduce Your Dependence on Fossil Fuels: A solar thermal system can provide up to 70% of a property's domestic hot water requirements throughout a full year, though it's more efficient in the summer months.

• Future-Proof Your Energy Costs: Not only will you experience a reduction in your current bills but solar thermal can also minimise the impact of inevitable energy price rises over the coming years.

• Improve Your Home: An approved, energy-saving feature can add value and market appeal to your property.

• Be Assured of Performance & Reliability: Average system lifespan of over 25 years with minimum maintenance required; warranty between 10-25 years.

Useful Information About Financial Help

Government has indicated that a financial incentive, the Renewable Heat Incentive (RHI) scheme should become available to home owners from mid-2013 to promote the use of technologies that generate heating from renewable sources, such as solar thermal and heat pumps. As with the existing Feed-In-Tariff scheme (FITs) for solar PV, the home owner will receive money in return for the use of approved technologies. Indicative tariff rate for solar thermal technologies (17.3p/kWh) that are MCS (Microgeneration Certification Scheme) certified and meet relevant required standards, would be paid to the home owner over seven years for each kWh of heat produced for the expected lifetime of the renewable technology, based on deemed heat usage and subject to energy efficiency minimum requirements for the property. (Green Deal assessment)

RHI is being introduced in two phases, Phase One (Oct 2011) is for non-domestic sectors and Phase Two (mid-2013) will see it expanded to include more technologies as well as support for households.
Government has also confirmed that systems installed under RHPP 1 or RHPP 2 (see below) will be eligible for RHI provided full RHI scheme eligibility criteria are met.

For domestic installations in the meantime, Government has already introduced the Renewable Heat Premium Payment (RHPP) scheme. RHPP entitles a home owner installing a renewable heat technology to apply for a cash voucher - £300 in the case of solar thermal. RHPP 2 is available now and until 31st March 2013, subject to available funding and can be applied for through the Energy Saving Trust website, where there are further details including important eligibilty criteria -

www.rhincentive.co.uk