Solar Electricity (Supply-only) in London

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.

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.

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.