Find a Solar Panel Installer you can trust in Melton Constable.

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.

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’re thinking about installing a solar system in your home or property, this is probably one of the things you’d like to know before making a purchase decision. Well, you’ve come to the right place! In this post, we’re going to give you a good insight into this to help you make the best informed decision possible moving forward. Let’s take a look!

First and foremost, it must be stated that providing a short and accurate answer to this question is nearly impossible as the amount of time a solar panel will last after dark is influenced by a number of factors. These factors include the size of your solar system, the battery size as well as your power usage. As you would have imagined, batteries are charged when there is excess energy that’s being produced by your solar system but it’s not being incorporated to power your home or property. More often than not, this occurs during the sunlight’s peak periods from about 10am to 2pm.

The time it’ll take for your battery to charge is influenced by the size of your solar system in Kilowatts, the size of your battery as well as the rate in which your system is being used. Your battery can be charged in a day or two, of course unless it’s an over-sized battery for your system.

When the sun sets and your solar panels can no longer directly run your appliances via electricity generation, the battery then kicks in. You will use about 1 to 2 kW’s of power if you’re watching TV, using the oven as well as lights internet etc. in other words, even a small solar panel battery will last all night. However, the same doesn’t apply if you’re having a party with running floodlights, three fridges and air conditioner as the battery will drain a lot faster.

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.

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.

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.

There are two different types: flat plate, where lots of thin tubes carry water through a flat absorber panel, and evacuated tube, where vacuum glass tubes capture the sun’s energy directly. There is little difference in performance between the two but evacuated tube panels do more obviously extrude from the roof.