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SOLARSOGOOD.ORG.UK About solar PV Basically, solar panels come in two types; there are those that rely on the heat of the sun (even on a cloudy day) to warm water contained in the panels (well, they are clustered tubes actually) and then use that heat to partially or fully heat up a hot water cylinder for your general hot water usage, via a pumped solution. The other type are solar PV (photo voltaic) that generate electricity in the presence of light, or more precisely, solar energy from the sun. Again, the sun does not need to be shining as some electricity is generated even through cloud - sometimes quite thick cloud. Obviously a nice bright and clear sunny day is better than a cloudy one. Ok, how do solar PV panels actually work? Solar PV panels can be fitted on any roof
aspect but work best here in the I will concentrate on the type of panels I have fitted to my existing roof. These are often referred to as 'hybrid' panels as they are a combination of mono-crystalline cells surrounded by amorphous silicon cells which work well in both strong sunlight and cloudy conditions. (The technology is also available in the form of replacement roof tiles - i.e. a collection of mini solar PV panels that resemble roof tiles when fitted). When light falls on solar PV panels, electrons are knocked loose and flow towards the metal contacts within the panel and therefore electricity (DC - direct current 12v in my case) starts to flow. A good explanation can be found here: http://www.howstuffworks.com/solar-cell.htm Each panel is connected together and then
the resultant 12v DC (direct current) electricity is passed, via
negative and positive isolation switches, into a device called an inverter.
The job of the inverter is to convert the 12v DC electricity into that which
matches the local electricity supply from the national grid. This varies
somewhat from area to area and from minute to minute. The http://www.nationalgrid.com/uk/electricity/ So, once the electricity leaves the
inverter it's at around 230v AC 50Hz whereupon it is connected, via isolation
switches, to your consumer unit. At this point it helps to supply the demand
for electricity at your property or excess is fed back into the national
grid. In the event of a national grid power cut, all
grid-connected solar PV systems shut off their supply automatically within a
split second else local power workers might receive a shock or two from your
system whilst working on a local problem! The isolation switches after the inverter
(which can be fitted within the loft space and function fully automatically)
and before your consumer unit are also very important to switch off the
power from your system to allow work to be undertaken on your own home mains
electrics. All good solar PV installation comapnies will comply with the need
to clearly label this requirement. Hopefully this all makes sense at this
point. Another good series of examples is to be found at my installers
website here: http://www.sunpowered.co.uk/SolarElectric/solarelectric.htm Anyway, now navigate to My
Installation for further details about my setup. |
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