Substantial Savings with Solar Energy

Local man’s solar collectors shine after 15 years

As a mechanical engineer, County Down man, Peter Hirsch was impressed when he first witnessed the use of solar power to heat water, in France, over 16 years ago. He was surprised by the high temperature of the hot water on a camping site where an efficient, yet unsophisticated devisce was using the rays of the sun to produce very hot water.

When he returned to Northern Ireland, tempted on by the possible economic saving and spurred by his 40 year interest in renewable resources, Peter researched solar collectors, flat plates and evacuated tubes. Peter decided on evacuated tubes as the solar collector is insulated from the elements, therefore performance would be greater.

He found also a most original invention: the heat pipe, a sealed copper tube containing water at a very low pressure, mounted with one end higher than the other. If the top end is placed in a cooling agent and the bottom end is exposed to solar radiation, the water will evaporate at the bottom, rise to the top, be cooled and run down in liquid form to be evaporated again. The cooling agent can be used to move heat to where you want it - and Peter wanted it in his hot water tank!

Peter was pleased to see that the manufacturer - Thermomax – now a part of  Kingspan Renewables - was a Northern Ireland company. with factories not only in Bangor but also in South Wales, where he also has strong links. While Thermomax exported all over the world but had sold very few installations locally, he thought it very likely that local sunshine would be sufficient to make an installation profitable. He had no south facing sloping roof and so installed, on a flat roof, an array of 20 collector tubes, facing due south and tilted at an angle corresponding to the latitude.

Almost 15 years on, the system still stands the test of time, despite exposure to gale-force winds on a regular basis and despite no maintenance or cleaning whatsoever. The 20 tube Thermomax collector is like new and still just as efficient and economical as it was when installed.

Installation was quick, simple and required no heavy lifting equipment. Peter and his step-son, a heating engineer and plumber, installed the Thermomax solar collector and a new, larger 250 litre hot water tank in just two days, causing minimal domestic disruption. To be suitable for solar collectors, hot water tanks must have a specially efficient heat exchanger coil as well as coils heated by an oil or gas fired boiler and electric immersion heaters and must be larger than normal. Kingspan also manufacture and supply solar ready hot water cylinders.

“When heat is captured by a solar collector, no carbon dioxide is released and it was obvious that, by using solar energy, there would be cost savings in terms of our annual oil bills," said Peter.

“I compared my oil bills before and after the installation of the Thermomax system - consumption fell sharply. The savings in oil costs balanced the cost of the solar tubes, the larger capacity water tank, the labour and installation costs within about four years. Our oil heating use is minimal from March to October. Except in very cold or rainy days, the oil-fired system is not used at all and the hot water is usually sufficient. We use more hot water but at a lower temperature - the reason for the larger tank. Since we installed Thermomax, hot water has become almost free all summer! With spiraling oil costs, we have saved literally thousands of pounds on heating and now, with oil ever scarcer and more expensive, will save even more!

“The Thermomax system collects heat efficiently all year round. Naturally, in the summer months, the solar collectors are at their most productive. But the system also works on overcast days, and in autumn and winter, when temperatures are not hot, the sun’s rays can still be captured and converted into hot water. One bright sunlit day in January with snow on the ground and a cutting East wind, I watched the control unit recording a collector temperature of more than 70 degrees Celsius. Even at night, if the air is warm, radiant heat is collected and added to the tank!

The Thermomax system, now owned and manufactured by Kingspan Renewables,  ensures the most effective transfer of solar energy into heat, giving better performance than flat plate collectors and still performs well in overcast days when flat plats actually radiate heat and  lose energy.

In 2005, Thermomax collectors were awarded with the prestigious International Forum Design award for excellence in product design. In addition, it was the first product to receive the European quality mark for solar collectors - the Solar Keymark.

Kingspan Renewables, based in Bangor, Country Down, incorporates the Thermomax and Solamax products.

Kingspan Renewables can be contacted on 028 9127 0411 or visit www.kingspan-renewables.com