Northstar Energy: Solar Water Heating performance

We estimate that the Northstar Solar panels will produce around 60-70% of your hot water over the year. They will produce more in summer when the days are long and obviously less in winter.

The chart shows the amount of energy required for your hot water and how much is produced by your boiler and solar system. In this example the solar system is providing over 60% of your total yearly hot water requirements based upon having 2 south facing genersys 1000-10 panels and a 200 litre hot water cylinder.*

The chart is based upon a 2/3 bed house. 2 Genersys 1000/10 panels and a 200 litre hot water cylinder.

Solar Water Heating performance and payback

The chart below shows a 4 to 5 bed house with three Genersys 1000/10 Panels and 300 litre cylinder*

Solar Water Heating performance and paybackIn the summer, when the days are longer they will produce up to 100% of your hot water, all free and all produced in an environmentally friendly way, however In December, when the days are short, they will obviously make a smaller (but still significant) contribution to your hot water needs.

At times when there is insufficient light to power the system (for example at night or on a rainy or foggy day), the water is heated in the normal way by your gas boiler or electric immersion heater. These will be the only times that you will be burning fossil fuel when heating your domestic hot water.

Solar payback People ask “What is the payback?” for solar thermal systems

"Well, first and foremost it does have a pay back. If you buy coal, oil or electricity or gas the supplier does not offer you any payback at all. No matter how much gas, oil or coal you buy and no matter how long you buy it for, you never get your money back. You have to service, maintain and renew you fuel burning equipment. Similarly the electricity company never offers you a payback.

Various government bodies sometimes define payback as the annual fuel bill savings divided by the capital cost. This is simply inaccurate misleading and wrong. If you take a proper view of payback, you must factor in future energy increases, take account of inflation, look at the savings in boiler servicing and the ability to make a boiler last longer and add in the parasitic losses that a solar thermal system suffers. Doing the sums properly most thermal systems offer a pay back of between 6 and 15 years, depending on the fossil fuel displaced, the future fuel inflation factor you use and the amount of hot water you use.

If a solar system is built into a home in the course of construction the payback period declines rapidly. Although payback is one way of looking at the cost it is perhaps more accurate to look at the return on your investment that solar thermal offers. Typically the financial savings of a good solar thermal system will be equivalent to a tax free return on investment of between 8% and 12%."

By Robert Kyriakides, Director of Genersys Plc.

For advice, information or to book a free home visit to discuss your personal requirements please call us on 08456 800 881 or use our online form.

( *data for performance figure were carried out by T*SOL Pro - the Simulation Programme for Solar Thermal Heating Systems. The results are determined by a mathematical model calculation with variable time steps of up to 6 minutes. Actual yields can deviate from these values due to fluctuations in the weather, consumption and other factors. Full results available on request.)

Recent Installations

Guildford, Surrey

3 Genersys 100/10 panels used for hot water

System: 2 Genersys 1000/10 panels

Location: Guildford, Surrey

See our latest installations

Northstar Energy

313 Church Lane

West Sussex
BN17 7QJ
Telephone: 0845 6800 881