Solar

Generation of DC voltage using sunlight is now a very cost effective way of generating your own electricity for your home. Obviously generation can only happen during daylight but even on an overcast rainy day you will generate some power. The biggest issue is that energy is only present when the sun shines so you either dont consume it in the house or you can now export the excess electricity back out to the grid if permitted. With the addition of battery storage it is possible to store that excess electricity in the battery that was generated by the solar PV for use at a time when the sun is not shining. You can find out more about battery storage here.

Solar PV does have a degradation in efficiency over its operating life which is guaranteed by panel manufacturer usually over 25 years. It is now over 10 years since the government sponsored schemes encouraged home owners to purchase solar PV panels for their home using incentives such as feed in tariff. Technology has moved on since 10 years ago and panels have become slightly more efficient in that time (maybe 3-4%) but still not significant, but what has changed significantly is the cost of panels.

The systems are relatively maintenance free compared to a solar thermal system and require no specialised regular maintenance unlike a solar thermal system.

Another advantage that solar PV has is that electric energy can be converted into heat with near 100% conversion efficiency. This is ideal when your electricity export with your supplier is not very high or if you were an original Feed In Tariff (FIT) customer where there is a deemed export. There are a number of devices on the market that can do this called solar diverters.

There are a couple of different domestic types of solar thermal systems namely evacuated tubes and flat plate. Flat plate are the most common and also have the most longevity. They both have a heat transfer fluid running though them that is usually pumped and heat is transfered into a heat store or a hot water cylinder. A pump controller is required to ensure the transfer solution is only transfered when the temperature on the solar panel is higher that the store or hot water cylinder.

Relative to a solar PV system there is much more that can go wrong with a solar thermal system compared to a solar PV system due to high temperatures and moving parts and safety components in the system. If there is no more heat able to be taken up by the heat store or the hot water cylinder that heat needs to be rejected and if not very high (+100 Deg C) can be reached resulting in breakdown of the transfer fluid. It is advised to regularly have maintenance check on a solar thermal system to ensure it is operating optimally and safety devices and frost protection is adequate.