Solar Electricity (Supply-only) in Wales

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.

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.