Find a Solar Panel Installer you can trust in Sherborne.

It may be hard to believe with the summers we have in the UK, but there is more than enough sunlight to power solar panels. Solar PV (photovoltaic) panels operate in daylight, rather than needing direct rays from the sun so they’ll work throughout the year.

If you’re considering getting a solar thermal system, one of the first things that comes to mind is the possibility of the system functioning properly during the cold months. The short and simple answer to this question is yes, a solar thermal system works in the winter. However, the downside here is that it’ll be a lot less efficient when compared to how it operates during the warmer months or summer. As a result of this fact, you’ll likely need to rely more on your boiler, immersion heater or any other backup heating system during this period as your solar thermal system will fail to contribute as much as it does during the warmer months. So what exactly is the reason why solar thermal is less effective and less efficient in the winter period? Let’s have a look!

As you know, solar thermal system banks on the sun’s energy to heat the water for your home’s use. During the cold months or winter, the sunlight becomes a lot less available when compared to the warmer months, as a result, there’s less sunlight that’s available to be used for its solar energy. And even more so at the periods when the days are shorter or skies are clearly overcast.

Also having a great impact on a solar thermal system’s output is heavy snow. Flat plate collectors normally have the capacity to cope better during snowy conditions as the light that’s able to travel through the snow will heat up the absorber plate - thereby making the snow slide off more quickly. However, the case is contrary with evacuated tube collectors which possesses a form of vacuum insulation that’s crafted to minimize the loss of heat, meaning they can’t generate heat to melt and cause the snow to slide off in a similar way.

Most domestic solar thermal panels do not need planning permission and are covered by permitted development rights. There are restrictions on the size and location of these systems. If you live in a conservation area or listed building, or want to install a very large solar thermal system, check with your local authority to see if you will need planning permission.

To have your solar panels working at full strength at all times is crucial as this can go a long way to help you reduce your energy bill. In order to achieve this, you simply can’t afford to ignore having them regularly cleaned and free from all sorts of dirt, dust, debris, pollen, bird droppings and the likes. Now it’s quite reasonable to think rain or wind should be able to get the job done, but unfortunately this is not so. What solar panels need is a proper clean which you can decide to do by yourself or call in a qualified professional – the latter which is strongly recommended.

Cleaning of solar panels has to do with working at heights which can be very dangerous especially if you don’t have enough confidence to pull it off. And even if you have zero phobia for heights, solar panel cleaning requires experience as well as some specialized skills and tools possessed by the professionals. However, the question here is, how often should solar panels be cleaned to keep them operating at optimal efficiency?

Well, according to the manufacturers, solar panels should be cleaned twice a year. However, if this is something that you feel is not achievable by you, then you should at least give then an annual clean. The best or most advisable time to do this during the year is at the end of the summer months. This will ensure that you have a fully functioning solar array which is ready and prepared to withstand whatever the cold period throws at you. At the end of the day, you’d have them looking spotless clean while also working at full strength and reducing your energy bills.

It’s vital to purchase a solar panel system that suits your property. If you’re investing in a solar panel system, it makes the most financial sense to get the biggest one possible. However, whether you can do this or not depends on budget and space.

Here’s an idea of how much roof or ground space you’ll need to install a few different sizes of commercial solar panel system.

Solar panel system size, No. of solar panels, Approximate area required

11kW, 44, 64m²

20kW, 80, 116m²

30kW, 120, 173m²

40kW, 160, 231m²

50kW, 200, 288m²

In theory, you can fit solar panels yourself. In practice, it’s worth leaving it up to the professionals.

If you get DIY solar panels and install them on your roof yourself, you won’t be able to apply for the government-backed Smart Export Guarantee (SEG). The SEG pays you for every unit of electricity you generate and send back to the grid, so it’s a scheme well worth signing up for. However, you must have your solar panels installed by a Microgeneration Certification Scheme (MCS)-registered engineer or company, so you’ll miss out if you install the solar panels by yourself.

The other thing to consider about installing solar panels yourself is that you’re dealing with electricity. Electricity is extremely dangerous if handled incorrectly, so if you don’t have any qualifications in working with electricity you could be putting yourself and your family at risk. Connecting DIY solar panels yourself and doing it incorrectly could mean that you give yourself an electric shock or cause a fire. If your home is damaged due to a fire caused by solar panels you’ve installed yourself, it’s unlikely that your home insurance company would pay out.

Before having a go at installing your own solar panels, do some quick sums to see how much money it could really save you. A 3.5kW DIY solar panel kit will cost around £4,000-5,000. According to the Energy Saving Trust, a home in the South East of England where most occupants are out all day until 6pm would save around £100 a year on their electricity bills. That means that you wouldn’t break even until 40 years, but solar panels last around 25 years on average. However, if you have your solar panels installed by an MCS-registered installer and they cost £4,500, you could save £220 a year including your SEG payments. That brings the payback time to around 20 years.

So although the initial outlay is slightly less when you install solar panels yourself, it’s much better to have them installed by an MCS-registered engineer so you can take advantage of the SEG payments.

How much energy a solar panel produces depends on its manufacturer and exposure to the sun. A good-quality solar panel typically has a power output of about 300 watts per hour, but this can vary from about 240 to 360 watts. How much energy your solar panel will produce per day depends on how many hours of unshaded daylight it’s exposed to.

Here’s an idea of how much energy you could expect a large commercial solar panel installation to produce in a year.

Solar panel system size, No. of solar panels, Annual electricity output

11kW, 44, 9,350kW

20kW, 80, 17,000kW

30kW, 120, 25,500kW

40kW, 160, 34,000kW

50kW, 200, 42,500kW

If you want to connect solar panels to a battery, it’s likely that it’s because you want to make sure that you don’t waste any electricity when your solar panels are generating energy but you’re not around to use it. Batteries are particularly useful for homeowners that have solar panels but are out during daylight hours; with a solar battery system, your solar panels will feed the electricity they generate into the battery for you to use when you get home.

If you want to connect your solar panels to a battery, the best thing to do is to get in touch with an MCS-registered company who can talk you through your options. There are different size batteries and the size that’s suitable for you will depend on how much electricity you plan to store and how large your solar panel system is. Some of the top brands of battery storage system include Tesla, SunPower and SolarEdge. If you want to be able to take advantage of selling electricity back to the grid through the Smart Export Guarantee (SEG), it’s worth getting an MCS-registered company to install your battery for you, as you may not be eligible for payments if you connect your solar panels to a battery yourself.

You should also consider whether your solar panel system is a ‘storage ready’ solar system. Today, most systems will be, since battery storage is becoming much more common. This means that your solar panel system will have an inverter that can easily integrate a battery. If this is the case, you should be able to purchase the battery you want and follow the manufacturer’s instructions to install it.

However, it’s worth bearing in mind that electricity is extremely dangerous when handled incorrectly. If something goes wrong, you could electrocute yourself or cause a fire. If your solar panels and battery cause a fire, it’s unlikely that your home insurance company would pay out if you connect the battery yourself. That's why it’s best to ask a reputable installer with all the correct qualifications to connect your solar panels to a battery for you.