Solar power is probably the cleanest, most viable form of renewable energy available. The simplest use is as solar thermal hot water but the really clever stuff is to generate electricity. This uses the same principle to power your garden solar lights or solar garden water features. So their availability and wide use in gardens shows exactly how versatile it is as a source of energy. And as you can see from the selection of garden stuff the technology and the systems are becoming more compact all the time.
Photovoltaic (PV) cells or tiles work by converting some of the energy in sunlight into electricity that can be used in your home but how does it work? Contrary to popular opinion it doesn't need bright sunlight just light, which is very solar calculators work indoors under normal lights. The cell consists of a positive and a negative slice of silicon placed under a thin slice of glass. As the light photons beat down on the PV cell they knock electrons off the silicon. These electrons are attracted back to the silicon but are trapped by the magnetic field that is formed from the opposing fields. Small wires on the silicon catch them and create a circuit just like a battery. This reaction, again like a battery, creates direct current (DC) electricity so to convert it to alternating current (AC) electricity you use in the home it must be passed through an inverter. Some of the power is lost in this part of the process as the inverter is only around 95% efficient but this is a very good in comparison the amount of electricity that the Grid loses to get power to your home from a Power Station (sometimes as much 60%).
Now all of that probably sounds very complicated but all you need to know is that you buy something that looks like a roof tile which clips together to make a solar array (roof to you and me) then you attach the wires to the inverter and you’re away. There are no moving parts so there is little or no maintenance required and means installation can easily last 30 years.
The design details are bit more tricky as you need to make decisions like do you generate all your electrical demand, just some of it or more than enough to ‘sell’ your surplus (called a Grid tied system). Broadly speaking the amount you generate is directly related to the area of your array so the bigger the better! A Grid tied system means during those times when you create an excess of electricity you can sell it back to the Grid. The simplest way is through a reversible electricity meter but the best way is to have import and export meters as you should get paid more for exporting than importing (we should all be lobbying for a FEED tariff like Germany). The Grid connection also means that if you not generating your own electricity (like at night) it just flows the opposite way from the Grid. True ‘Off the Grid’ systems have no grid connections, as the name implies, and need more thought because you will require storage systems like batteries (for night use) and ‘heat sinks’ (normally an immersion heater in a hot water tank) to get rid of your excess during peak power at midday. Themselves and even use the DC electric directly with special lighting circuits so saving the cost of the inverter can use really simple systems to power Outbuildings. This is how car battery driven caravan systems work, and indeed you can get solar panels to do exactly that job for your caravan.
An efficiently solar powered home will be able to reasonably create between 75 and 100% of their own power and because of the grid tie system this means you may not have to pay for electricity ever again. For help to design your system just give us a call.