Ask an Expert: What Do I Need to Know About Solar Panels?
Interested in fitting ecofriendly solar panels to your home? Read this expert advice on the benefits and considerations first
In addition, you improve your carbon footprint by not relying on electricity produced by burning fossil fuels. So if the summer sun is turning your mind to solar power as well as sunbathing, read on to learn a little more.
Professional advice from:
Chris Seymour-Smith of Seymour-Smith Architects
Alan Budden of Eco Design Consultants
Andy Dedman of Luxco Energy
As well as reducing your reliance on electricity produced by burning fossil fuels, you can also benefit financially from installing solar panels. For architect Chris Seymour-Smith, installing them on your home is a no-brainer. ‘As an investment, you should put solar on your roof,’ he says. ‘It pays a far better return than having your money sitting in the bank, with no risk. I think it should be a legal requirement for all new houses to have solar and thermal installed.’
Alan Budden advises you consider insulation first, though. ‘Reducing energy consumption should always be the first option prior to adding solar panels,’ he says. ‘The cost of energy reduction measures, such as increased insulation, are usually less than solar panels, so their payback times are therefore often shorter and their lifespan longer. If it’s an either-or situation, go for a reduction in energy usage through insulation, then, when it’s paid for itself, buy the solar panels.’
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The government introduced the Feed-in Tariff scheme (FIT) in April 2010 to encourage take-up of renewable energy systems. This means you are paid for every unit of electricity you produce, regardless of whether you use it or not. The rate is currently guaranteed and rises each year, providing a tax-free income for your home for 20 years.
In addition to the FIT payments, any electricity you don’t use is exported back into the National Grid and your electricity supplier pays you an export tariff for this. ‘The house takes what it needs and the rest is pushed back into the grid,’ says Andy Dedman.
Systems also exist that allow you to store the surplus electricity you produce, but they are expensive, so homes instead typically use electricity from a standard supplier as well to cover night-time usage and cloudy days.
Be aware that adding value to your home shouldn’t be the driver for installing solar panels. While they will give you a return on your investment while you’re in the house, they don’t always add value: some potential buyers are looking for eco features, but many are more interested in square footage.
The south of England gets more sun than the north, so homes in the south tend to produce more electricity, but solar panels work anywhere and still make economic sense in more overcast corners of the UK. ‘There are almost 20 times more solar panels in the northeast compared to London and the southeast,’ says Andy. ‘They work fine in the north, but you are just playing a slightly longer game in terms of returns.’
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‘South-facing roofs are ideal,’ says Andy, ‘but we have been monitoring output from east/west-facing homes with panels on each side and found the payback is pretty similar.’ Of course, you don’t need to mount panels on the roof. ‘If you have land, you can set them up in your garden,’ says Andy.
‘Not all homes are ideally located to achieve sufficient solar gain, due to shading,’ warns Alan. ‘There are locations where other renewable options would be more appropriate, but saying that, most buildings are suitable.’ He agrees that east/west-facing roofs are as good as south-facing ones. ‘They have a greater overall area and peak in the morning and evening when we have the greatest demand for energy,’ he says.
When it comes to deciding how many panels to install, the more the better seems to be the rule. ‘We don’t recommend less than eight panels for a viable system that supplies a typical house,’ says Andy. But, he adds, the more panels you can install, the faster you will see a return. ‘The economies of scale get better the more you install,’ he says. ‘We charge the same to put up eight panels as we do to put up 16. All the registration costs, scaffolding and labour are set fees.’
Installing eight panels will set you back around £4,000, but official statistics anticipate you will have paid this off and therefore be earning from your electricity exports within 10 years. ‘Actually, with eight panels we think it’s more like seven years and with 16 panels and a 4kWp system, you can be receiving payback in five or six years.’
‘You need to factor the cost of a new inverter into your financial projections, too,’ says Chris. ‘This converts the panels’ electricity into a format the National Grid can cope with. It generally only survives for about 10 to 12 years, unlike the panels, which will go on for 20 to 25 years. Go for a good-quality inverter, such as an SMA Sunny Boy.’
There are numerous solar panels on the market, but they tend to be fairly similar in terms of efficiency. ‘All standard 250w monocrystalline modules generate the same efficiency, and they will all be under warranty for 10 years for workmanship and 25 years for performance,’ says Andy. ‘There is nothing much that can go wrong with a panel. It has no moving parts and is quite a simple design.’
With this in mind, Andy recommends basing your choice on colour. ‘All-black panels tend to blend in best on roofs, so we recommend going for the cheapest available panels that are black,’ he says. If you want any kind of upgrade, look to splashing out on a good inverter (see above).
Ideally, factor in solar panels from the start of a home build or during building work. ‘If you’re going to add them, plan this in from the beginning if possible to ensure the best aesthetic, environmental and cost-effective solutions are achieved,’ says Alan.
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If you live in a conservation area or own a listed building, check with your local planning authority before you install solar panels on your property. ‘Listed buildings have been listed for a reason and bolting panels onto them in my view feels wrong,’ says Chris. ‘You would need to get listed building consent, and if you are in a conservation area, you will need planning permission.’
Alternatively, consider other locations for panels. ‘Everyone thinks of solar panels as being on the roof, but you can have ground-mounted panels at the end of the garden or install them over your carport, garden shed or greenhouse,’ says Chris.
‘If you have an existing pitched roof, you don’t need permission to install panels,’ says Andy. Be aware, though, that installing solar panels on flat roofs is subject to some restrictions. Frames are allowed to be a certain height, and if they go above this you must apply for planning permission before installing them.
Some people argue they are at work when their solar panels are generating most of the power, so they don’t get the maximum benefit. There are ways around this, though. ‘Washing machines and dishwashers with timers deal with this issue to some extent,’ says Chris. ‘You could also fit an ImmerSUN unit, which directs unused electricity into your hot-water tank via an immersion heater, so you have lots of hot water and rely less on oil or gas.’
Chris advises the best way to get the most from your solar panels is to be mindful of reducing your power usage in general. ‘Buy a Wattson unit, which is an energy monitor that tells you exactly how much power you’re using, how much it’s costing and, when you have panels, how much you’re earning,’ he says. ‘I love it when mine glows green – it means I’m generating more energy than I’m using!’
More importantly, it spurs you into turning off lights and any appliances that aren’t in use. ‘You start to see the numbers on the dial falling instantly,’ he says.
Do you have solar panels on your home? Share any tips about them in the Comments below.