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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.

If you want to test your solar panel system to see if it’s working properly or just to see what output it’s giving, you can do this using a multimeter to measure current, or amps, and voltage.

Before you start, you’ll need to find the voltage (v) and current (A) ratings of your panel. You should be able to find them on the back of the panel. You should also make sure that it’s a nice clear, sunny day to get the best readings out of your panel. You should also check that it’s safe to be up on your roof!

To measure open circuit voltage, you’ll need to make sure that your solar panel is completely disconnected from your system’s regulator and battery (if you have one). Angle the panel towards the sun, and ensure that your multimeter is set to measure volts. Measure the voltage between the positive and negative terminals by connecting the negative contact on the voltmeter to the negative on the panel and the positive contact on the voltmeter to the positive on the panel.

Then, you can move on to the short circuit current. Follow the same steps as the open circuit voltage, but ensure that your multimeter is set at 10A to start with.

Only try to test your solar panel if it’s safe to do so. If your roof isn’t accessible without scaffolding or specialist equipment, consider speaking to an MCS-registered solar company about your concerns. They may recommend that they come to service your solar panel system.

Yes – solar panels do work in winter. Contrary to popular belief, solar panels can still work under daylight, even if it's not hot. Of course, they won’t generate as much electricity as they would during the summer months, as the days are shorter, but they will still generate electricity during those daylight hours.

Once you know how solar panels work, it’s easy to understand why solar panels work in the winter. Solar panels are made up of photovoltaic (PV) cells, which are units usually made out of silicon. These cells contain electrons that create energy when light hits them. The cell can then convert this energy into usable electric current and into your system to be used around the home.

Although it might seem strange, solar PV cells can actually work better when it’s cold. Too much heat around the cell can cause it to be inefficient, due to the difference in energy between the energy from the sunlight and the electrons in the solar cell. During cold weather, the difference between them is higher, so more

The higher the energy difference between the two sets of energy sources, the more power that the cell can produce when it’s struck by light. Of course, the downside is that there are fewer daylight hours in the winter, so you’ll still see a drop in energy production – but at least you know that your solar panels are still working efficiently. The other thing to bear in mind is that obstructions like snow and lots of cloud cover will impact the amount of electricity your solar panels will produce. Luckily the UK doesn’t get too much heavy snow, so any snow that does settle on the panels will melt quickly. As for cloud cover, even on exceptionally cloudy days your panels will still generate some electricity – just not as much as they would on a clear day.

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.

Yes – solar thermal can be used for central heating. Solar thermal panels work by collecting heat from the sun, either through evacuated tubes or flat plate collectors, and transferring that to a heat transfer liquid that heats your hot water. This can then be used to preheat your central heating.

You’ll need a hot water cylinder to store the water that your solar thermal panels heat up. It’s likely that you’ll need an immersion heater or boiler to heat the water further so you can use it for your central heating, and as a back-up during the longest winter months since the solar panels won’t be able to generate as much heat.

In our opinion, it’s best to use your solar thermal panels for hot water rather than your central heating. That’s because you use hot water all year round, whereas you probably won’t have your central heating on in the spring and summer, when the panels can generate the most heat. For central heating, air- or ground-source heat pumps are a great renewable option, and you can even power them with electricity from solar PV panels if you want to be as eco-friendly as possible.

How long your solar panels will last depends on their age and quality. Most modern solar panels have 20-30 year warranties, but this doesn’t mean that they’ll stop working at this point. Many will stay at a good efficiency level for up to 40 years, while others will start to decline earlier.

Solar PV panels work by converting sunlight into electricity. They’re made up of photovoltaic cells, which take in the sun’s rays and turn it into direct current (DC) electricity. The current is then channelled into an inverter, which converts it to alternating current (AC).

Once converted to AC, the electricity is ready to use. It’s fed through a meter and into your property’s consumer unit, and is automatically used to power appliances and heating systems. Your system will automatically switch between your solar electricity supply and the national grid, and export any solar electricity you don’t use to the national grid.

You shouldn’t need to maintain your solar panels much at all as long as there’s nothing piled up on top of the panels that could block out the sun. They are installed at an angle, so when it rains the water runs off them and gives them a clean. However, if this doesn’t quite cut it, you can spray them with a hose a few times a year.