Solar Thermal Systems ? Some respite for Hard times

Hard times are on Ireland. Cash is hard to come by. Social welfare benefits and minimum wages will be reduced in an attempt to cut down the 2011 budget by Euro 6 bn, it is said. Only way for you to come out of the quagmire is to cut down your own wastages and improve the efficiency to optimize the usage of your earnings. The winter too is on you and imported fuel is going to take it’s toll. It’s time to think of going for indigenous sources of fuel sources and how to harness it with minimum expenditure.

Greener Homes Grant Scheme for awarding energy efficiency upgrading grants prescribes Solar Thermal type solar energy converters for home heating and domestic hot water applications. As you know, for such a system you are entitled for grant of up to Euro 1,500 and Euro 1,800 for Flat Plate type thermal collectors and Evacuated Tube type thermal collectors respectively, (based on Euro 250/m2 and Euro 300/m2 respectively for up to a maximum of 6m2 panel surface area).

Now, it becomes evident to you that there are two different technologies available in hot water systems to select .Which is the best suited for your requirements? What if your choice is the wrong one? We give below an insight into the two different solar thermal panels to enable you be aware of where you stand.

Types of Solar Thermal panels
The two basic types of solar thermal panels as mentioned before are:

Flat Panel Type
Vacuum tube type
Ultrasonic welded, selective surface coated copper plate Panel
Low iron, tempered glass with 91% transmission certified to EN 572-5, EN 12150-1 or their equivalents.
UV durable EPDM and silicone enclosure sealing against water
One piece, channel type glazing gaskets with moulded corners against water penetration
Electro statically black coated all Aluminium collector cases
CE certified high density Rockwool Insulation
Flexible connections for ease of installation
Back sealing provided by clamps and silicone
Air vent holes to prevent internal condensation
Back plate of embossed aluminium sheet.
Special black coloured (for better absorption of solar heat) glass wool wall insulation

Evacuated Type Solar Thermal Panels
In contrast these panels are more complex but are more efficient, durable, longer lasting and more reliable. Interestingly evacuated type solar thermal panels can provide heat energy during all seasons and cold, wet and windy conditions. (This is achieved by the low thermal losses provided by the vacuum of 10 -6 in the collector tubes).

This eliminates two of the three ways heat energy is lost, namely conduction, convection and radiation. The elimination of the conduction and convection makes it possible for the tubes to make use of low levels of diffused radiation. Evacuated type Solar Thermal Panel is also highly efficient. They can also therefore be adopted for domestic central heating systems.

The evacuated tubes are made of special glass which gives it good transmissibility with low reflection losses. They are highly durable too. As a consequence they are also relatively more expensive. The high solar energy absorption of evacuated tube solar thermal panels is achieved by the use of an absorber which consists of absorber plates coated with a special high efficiency selective coating which enable maximum solar radiation absorption and minimum loss of thermal radiation.*

Whatever may be your selection for your home hot water and space heating needs, approximately 70% of the annual fuel need may be shared by a solar thermal panel installation in your home.(The balance small portion will be provided by a conventional fuel or electricity using heaters). Best part is you will receive the solar thermal energy virtually at no cost to you or the country. Additionally the Greener Homes Grant will ease your initial investment too. Keep it in mind even in the low solar intensity and snowy winter too up to 30% of home hot water needs can be shared by a solar thermal installation.