Photovoltaics (P.V): Photovoltaic cells are made up of semiconductors, when light hits the cell some of this is absorbed through the semiconductor. This energy knocks loose electrons causing a current which can be drawn off and stored in a battery for later use.
Solar Water Heating: Solar Water heating operates in a slightly different manner, instead of collecting sunlight for electricity; it uses the heat from the sun to heat a fluid. This fluid is then piped through a coil in the hot water tank where it transfers the heat to the water.
Photovoltaics (P.V)
The main part of a Photovoltaic system is the panel itself. This is generally mounted to your roof, with all of the connections run through your attic space. Should you want to use the electricity generated yourself, battery storage is required. It is also possible to connect the system to the power grid and sell the power you generate, this is a popular option, although there have been reports of the connection fee being high. A general estimate is about £150 to £200 off your electricity bill per year.
Solar Hot Water
Once again, the main part of this system is the panel itself. These panels tend to be heavier than their photovoltaic counterparts since they also need to support the weight of the heating fluid in their pipes so when considering this option, you should always seek advice from your engineer. A compatible hot water tank is also required; this can either be a dedicated tank or a combination tank that also has an immersion heater built in. If you decide not to opt for the latter option, you will still need an immersion heater to provide a backup system for when your solar panel can't meet the demand.
Combing Green Technologies
At the core of a heat pump is a compression unit. This would normally be run from the mains power. The main problem with mains power is that you can't guarantee its source, the power supplied may be obtained from a coal fired power station. With the aid of a Photovoltaic system, the need for mains power is removed and you have a truly renewable system with no need to pay for the running cost of the heat pump.
Benefits
- Solar panel systems are a proven technology, with widespread use throughout the world, and even in space
- The panels use a previously wasted space, your roof.
- Very little maintenance is required
Drawbacks
- The location and angle of a solar panel can affect its performance. If your roof doesn't catch the sun or is overshadowed, then you won't see the reduction in heating or power costs.
- Your panel only work during the day. Your solar panel will work best in direct sunlight. On a cloudy day, you will still generate energy, but at a reduced efficiency, however when the sun is down you stop generating any energy. This should be taken into consideration when comparing to non weather dependant technologies such as ground source heat pumps.
- In most areas, you should always seek planning permission. This process can take up to a couple of months, and although councils are encouraged to allow solar panels, there are areas which will not allow any at all.
Solar panels can be a great asset to your new build if careful planning has gone into their positioning. The large variation in available panel systems makes this one of the most versatile green technologies on the market. As with other green technologies, grants area available to help with the cost. For further information, take a look at the Energy Saving Trust website.
