Solar electricity panels generate power from daylight, whether the sun shines or not.
If you’ve ever used a solar powered calculator or wrist watch, you’ve already experienced the reactive power of solar energy panels when you held your gadget up to a window or close to a lighting fixture for a quick charge.
Multiply that tiny photovoltaic cell (PV) in your device a few thousandfold and you’ve got a system that could provide a substantial part of your household electricity and even earn you a bit by selling power back to the National Grid.
But not all the claims about performance and payback through energy efficient saving and government Feed-in Tariffs (the money you can make by generating and selling power back to the grid) are true in every case. And not all suppliers are qualified or reliable. A lot depends on where you live – location and orientation, how much you can spend, how much space you can devote to solar panels and how careful you are to avoid scams.
EST Buyer’s Guide
Asking the right questions before you commit is key to making the technology achieve its money saving potential. The Energy Saving Trust’s (EST) free, downloadable Buyer’s Guide to Solar Electricity is a useful source of information about:
* Site location
* Types of solar cells and how they work
* Connecting to the grid
* Local permissions
* Government Feed-in Tariffs
* Costs and savings
* Maintenance
* Warranties
* How to find a qualified and honest installer
Here are some highlights…
How does Solar PV work
Some solar panels are little more than heat collectors, designed to store the sun’s energy in pipes of hot water for home heating or hot water requirements. Photovoltaic cells (PVs) differ from these in that they actually generate electricity. Arranged in interconnected modules, called arrays, they convert light into electricity when the electrons in a semi-conducting material – usually silicon sandwiched between glass and polymer resin – become “energised” and flow through the material generating a direct current (DC). An “inverter” converts this to 240V which is connected to your home’s supply.
PV are rated by kilowatts peak or kWp – the rate of energy generation at peak performance (high noon underclear skies for example). The energy generated is measured in kilowatt hours (kWh).
In perfect conditions, a typical array could generate between 1200 and 2400kWh per year. According to the Energy Saving Trust (EST) an average home uses about 4000kWh per year on lights and appliances.
What to look for in an installer
1. Quotes:
* Detailed system specifications and costs
* Explanation of why the recommended system suits your needs
* Clear, easy to understand information and operating instructions
* Estimates of potential energy generation and what proportion of your annual use this is.
* Government incentives
* Payment options
* What is included.
2. Experience
* How many years have they been installing systems
* How long have they been in business
* Local references and installations you can check
3. Professional Credentials
* Microgeneration Certified (MCS)- required for you to be eligible for Feed-in Tariffs payments
* Proof you can check of MCS, City and Guilds or other credentials
* Membership in Office of Fair Trading or Local Trading Standards Scheme
The EST advises not to compare solar installers on cost alone but to consider technology types, independent test results carried out on installations, available options and a range of other factors.
What to avoid
Be wary of installers who:
* Stay in your home an unreasonably long time
* Offer you a high initial price followed by a discount
* Offer a discount for signing on the spot
* Withhold price information until the end of the visit
* Claim product availability is limited.
Visit the EST to downloadable a free copy of the full Buyer’s guide to solar electricity panels or telephone 0800 512 012 for independent, local advice.
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