Wheathampstead Magazine
Solar panels: Questions to ask before you decide
Solar power harnesses the natural energy of the sun to produce electricity, and over recent years many of us have begun to realise that this could offer many benefits to the average householder. According to industry sources, at the beginning of 2014 more than 500,000+ households had solar PV panels on their roofs and clearly that number is increasing all the time. So if you feel the time is right to begin to reap the benefits, for your own piece of mind, it’s important to do it properly. LocalLife spoke to local experts Solinvictus for their advice about which six questions to ask before you decide to install solar panels.
How many panels should I have?
The best way to judge how large a PV array should be is to start with your electricity bill. For the lucky few who don't use much electricity (less than 2,000kWh a year) a large array could be counterproductive as most of the electricity will be exported to the grid. On the other hand, a small array on a property with high use (more than 5,000kWh) wouldn't make much of an impact. So the owners of a one bedroom flat with low usage might choose a 6-8 panel array (1.8-2.2kWp) whilst a large house would do better with at least twice as many. You could add the impact of electric cars here too and 'oversized' installations are becoming popular in order to produce enough electricity to power the house and charge the car.
What do PV systems cost these days?
Much depend upon the efficiency of the panels you choose, the type of roof tiles you have and how easy it is to access the roof. Nevertheless, a small system (2kWp) should cost around £4,000, a 4kW system between £5,500/£6,000 and an 'oversize' 6kWp system about £8,000 (all inclusive of VAT).
Does the Feed in Tariff still exist?
Yes, it still exists although at a much lower rate than when it was launched in 2010 (4p per kWh rather than 41p). That makes the value of using the electricity much more significant than before but it's still possible to achieve a rate of return on your investment of as much as 10%. It won't last forever, however, as the Government intend to end the scheme in 2019 - catch it whilst you still can!
Can I store the electricity to use later?
Conventional PV systems only allow you to use the electricity when they're generating it. Adding a battery storage system gets around this by storing power in the middle of the day and allowing you to use it in the evening. Calculating the benefit of energy storage is important as is matching the battery size to both the expected use patterns and the size of the array.
How long do PV panels last?
The industry view is that there is 40 years worth of life in silicone cell technology and there are examples that NASA produced in the 50s and 60s still working today. Manufacturers back up this with typical performance warranties lasting for 25 years. There is some degradation of performance but you should expect at least 80% of the original performance after 25 years.
What should I look for in an installer?
Talk to several before making your mind up and you should get a feel for the sort of company you're dealing with. Look for experience with the components they're recommending to you and ask to see some of the installations they've done. Go online too and look for sites like YouGen and Which Trusted Traders to see what their existing clients have said about them.