Solar power can be safely split into two main components. Solar PV or photovoltaic panels and Solar Thermal or hot water using the power of the sun.

At the moment we are looking to get a 4 kwh system installed on our house roof before the FITs are cut back by this government. Currently the government will pay you 43.3p per kw of energy that you generate and also 3.1p per kw that you export to the grid.

In essence the export fee is next to nowt and can realistically be used as a bonus of abut £50 a year. The real money in PV is the generation fee part of the FITs. FITs are the Feed In Tariffs that you can get.

A 4 kw solar Photovoltaic system will cost around £9000 - £15000 depending on company used and the work needed on your property.

A bracket is fixed to your roof and the solar panels whether PV or Thermal are fixed to that. There is no major work needed on your current roof to install solar unless of course your roof is of poor quality to begin with. *

Once the panels are in place on the brackets they are all connected together. Once connected they are linked to an inverter which changes the power from DC to AC. If you have solar on two roofs then make sure you have the correct inverter installed as the inverter will generally only work to the lowest level of power so if one roof has 1 panel on and gives out say 10kwh and the rest of your panels give out 100kwh then the inverter will only put through 10 kwh per day. A split inverter or two separate inverters will give the maximum power that you generate. Worth asking your sales advisor about this.

From this point forward the wires are connected to the mains system with either an export meter or direct into the meter. The second version just stops your meter wheel turning during the day time and you use the electric produced in your home. This version enables the electric company you use give you 50% of the electric as "free" electric. This is where the rather wooly idea of 50% being exported to the grid comes in and the average of £50 per year. If you are out all day and don't use any electricity during daylight hours then you are exporting 100% but the way the system is set up you only get credited for 50%. If this is something you wish to look at further then you will have to contact your electric supplier and ask them to install a smart meter.

All houses are supposed to have smart meters installed by 2015 but at present the industry cannot decide on a standard model for all the industry so there are several which may become obsolete when the government and industry make their minds up.

The export meter will tell exactly how much you have exported to the grid and thus how much you will gain in the export tariff of 3.1 pence per kwh. Some electric companies are charging a fee of £50 per install and are giving this back after 2 years of continuous supply. If you move supplier then you lose this £50. On the upside, if you use no electricity during daylight hours then you could make around £99.00 per year from the export tariff. It becomes academic thereafter as you need to work out if you use say £25 of free electric per year then you will have saved £50 over 2 years....

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As a side note be aware that there may be some companies out there who are unscrupulous and say you need a new roof whilst giving you your solar quote. If it was me, I would then thank them for their time and show them the door immediately. You can then get advice and quotes from at least 3 reputable roofers and if they say you need a new roof so be it.