sustainable
T E C H N O L O G Y LTD
Solar Water Heating Panels
The vacuum tube contains a copper heat pipe, assisted by a metal heat transfer fin. Inside the heat pipe is a heat exchange liquid with a low evaporation temperature, as it is heated it rises to the copper header where it condenses and leaves its heat in your domestic water flowing through the header. This process is continually repeated during daylight hours and the water in your tank is heated by nature, reducing the amount of gas, electricity or oil that would have been used.
Annual Energy from a typical domestic sized 20 tube Thermomax evacuated tube thermal solar system
Total power from one panel is 1132 K/Wh/year, using a rate of 10.0 pence a KW gives a saving of £113 each year and a payback of 10 to 15 years (depending on the number of units in the system, assuming energy inflation at 5%). This is equivalent to a 3KW kettle boiling constantly for over two weeks in every year! That’s a huge amount of energy and all naturally from the Sun. Other panel sizes are available to suit your needs.
A properly matched system producing around 55% of a households domestic hot water usage. Based on a family of four with average water usage.
How would I be helping the environment with this system?
This system uses some of the energy presently going to waste on your roof. As part of an energy efficient system, a solar water heater will save fuel, help to achieve reductions in CO² emissions, by making use of natures energy, our exposure and that of future generations to dangerous technologies, such as nuclear power, will be reduced.
Which direction should my roof point?
In the UK, panels should face between Southeast and Southwest, and at an angle of between 20º and 60º from the horizontal. If you keep within these limits, then your output will be within 5% of the theoretical maximum. Overshading should be considered. Any tree, building or other obstruction that casts a shadow on the panel, will reduce the output for as long as it casts that shadow.
Most panels are fixed to a southerly sloping roof, which effectively determines the orientation and slope of the panel, and prevents much overshadowing.
Price from £3450 inc Vat and installation and warranties, 5 years for the Thermomax panel, 1 year parts and workmanship defects on other parts of the system.
Phone John Pasley B.Eng. Director of Sustainable Technology Ltd (01622 842612 or 0772 504 5445(mob)) for more details and a no obligation survey, or e-mail me at Info@SustainableTechnologyLtd.
In a few hours the amount of energy hitting the surface of the Earth from the Sun is equivalent to the energy used by humans on the entire planet in a year.
The absorber of a solar tube is the black coating on the inner tube. This special selective coating is excellent at absorbing solar energy (92% efficient), while only reflecting back a small amount (8%). The sunlight and is absorbed by the inner tube, raising the temperature inside. A vacuum between the two glass tubes greatly reduces any heat losses, improving performance in cold weather.
