Find a Solar Panel Installer you can trust in Swanage.

It’s important to get the right size solar panel system for your commercial property. Solar panels are usually installed on pitched roofs, although they can be fitted on stands on the ground if you have some unused outdoor space. The more panels you install, the more power you’ll generate, but there’s no point buying more panels than you have space for.

Solar panel system sizes are measured in kW. 4-10kW solar panel systems are usually too big for domestic properties but are ideal for smaller commercial properties. Here’s an idea of how many panels and space you’ll need for a few different system sizes:

System size, Number of panels, Area required (approximate)

4kW, 16, 23m²

6kW, 24, 35m²

8kW, 32, 46m²

10kw, 40, 58m²

Bear in mind that solar panels can’t be less than 30cm away from a roof edge, so you’ll need more space than the area that the panels take up.

If you’re thinking about getting a solar thermal system for your home, it’s normal to consider the possibility of using the system for central heating. So is this viable? In this article, you’ll learn how solar thermal panels can be incorporated for heating. Let’s have a closer look!

Heating and hot water systems, on the average, takes up a sizeable part ( up to 70 percent) of our energy bills. Now take a moment to imagine how cool it’ll be to generate your own hot water for free without having to depend on any supplier which in turn significantly reduces your energy bills. Well, this is exactly the work of central heating systems that are powered by solar. That’s super cool, right? Well, let’s have a look at how this works.

While solar panels generates electricity, solar thermal panels produces heat for hot water production. However, what’s important is the fact that they both make use of the sun’s natural energy to provide us with a free and renewable energy we can use in our homes. Here’s how it works.

Solar thermal panels directed at central heating incorporates the sun’s natural energy to heat water in a storage cylinder which is then available for use at home. These solar thermal panels are exposed to the sunlight by fitting them on the roof of the home. Generally, they’ll include tubes that contains liquid whose job is to collect the heat and then transfer it to a hot water cylinder that’s solar compatible in your home. The heat is generated for free and is also renewable. This is help you save lots of money on oil, gas and even electricity which you purchase to power the cylinder.

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

Solar cells , also referred to as photovoltaic cells (PV), absorbs energy from the sun and converts it to generate electricity. This, however, should not be confused with photovoltaic thermal cells or PVT which operates to generate heat for water in homes. Solar cells are linked electrically and also carefully organized into a large frame which is popularly called solar panels. Generally, solar cells are produced or made of silicon semi conductors which works to absorb sunlight and then turn it into electricity for use at a home. A solar panel comprises of either 60 or 72 solar cells which are electrically interconnected in series and parallel and also positioned in between glass and plastic which is then framed.

At present, solar panels incorporated for residential or domestic purposes only possesses the capacity to make use of only about 20 percent of the sunlight they’re able to absorb and convert it to electricity - also called solar efficiency. Available in the market are also a wide range of solar cell available for both industrial and commercial purposes. This type of solar panels have an efficiency rating of about 40 percent which will also automatically make them more costly than the domestic types.

One great thing about the solar industry is the fact that it keeps improving in such a way that raises both its efficiency as well as overall quality. And with further research and development, this is expected to even increase as the years go by. What’s more? As these aspects keep rising, it’s also expected that the solar panels price should be on a decrease. That way, they’ll become available to a wider range of individuals who’ll also like to save money on electricity bills and go greener.

Whether solar panel batteries are worth it depends on how much you’re at home and how big your solar panel system is. If you’re at home most of the day and your solar panels only generate enough electricity for you to use while for that day, then a battery probably isn’t worth investing in. However, if you have a large system that generates more than you can use or you’re out most of the day, then solar panel batteries are definitely worth it.

A solar battery storage system works by storing the electricity that your solar panels generated until you need to use it. That’s why they’re great for people that are out all day – your solar panels generate electricity all day whilst the sun’s out, but no one’s home so you’re using minimal energy except for things like your fridge and any appliances on standby. Most of the electricity charges your solar panel battery. Then, when you get home, your battery will discharge, and you’ll use all the solar electricity that your panels generated during the day.

Solar batteries are also excellent for people with large solar panel systems that generate more than they use in the day. Any electricity that you don’t use during the day will charge the battery, so in the evening when the sun goes down, you’ll just use the excess electricity that’s stored in the battery.

To work out whether solar panel batteries are worth it for you, you’ll need to work out how much of your solar electricity you’re using already. If you’re at home and you’re able to run your appliances all while your solar panels are generating electricity, a battery might not be worth it. Also, if you’re receiving export payments from the Feed-in Tariff Scheme (FITs) or the Smart Export Guarantee (SEG), you might want to look at the rate you’re getting paid. If it’s a good rate, it might be more cost-effective to continue exporting unused electricity to the grid. Speak to an MCS-registered installer that will be able to help you work this out.

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.

• The power of your solar panel system – there's no point buying a higher capacity battery if your system will never generate enough electricity to charge it
• How often you think you will need to charge your battery
• Your budget
• Whether you care about having the latest technology and a recognisable brand name