Find a Solar Panel Installer you can trust in Isleworth.

The more you’re at home during the day, the more you can save on your electricity bill, since solar panels generate electricity during the day. The Feed-in Tariff scheme (FITs) ended in March 2019, but the new Smart Export Guarantee (SEG) pays you, via your energy supplier, for the electricity you export back to the grid. With the savings involved in generating your own electricity and SEG payments, you can expect to save up to £390 per year on your electricity bill.

If you’re looking to install a solar thermal system in your home, this is usually one of the first concerns several homeowners have. Being fully aware that solar water heating systems are usually more expensive than their counterparts - the conventional water heating systems, the question arises whether or not you’ll be able to save some money from your solar water heating system in the long run. In this article, we aim provide an answer to this important question. Let’s take a closer look!

When it comes to solar thermal systems, the money you’ll be able to save in the long run depends on a wide range of factors. These factor includes:

✓ Your system’s performance.

✓ Your geographical location and solar resource

✓ Your household’s hot water demand

✓ Financing and incentive options that are available.

✓ The cost of fuel that’s being used for your alternative or backup water heating system, if you own one.

✓ The cost of conventional fuels such as oil, electricity or natural gas.

There are several benefits, however, that comes with the installation of a solar water heating system. Since the sun is absolutely free, future fuel shortages and price hikes will have little impact on you. Also, on the average if you decide to fit a solar thermal system your water heating bills is expected to drop about 50 percent to 80 percent. What’s more? The economics are even a lot more attractive when you’re just about to build a new home or refinancing. When you include the price of a solar water system in a 30 year mortgage, it’ll normally amount to very low price per month. Therefore, on a monthly basis you’ll be saving more and paying less.

If you’re thinking about installing a solar thermal system in your house, it’s always important to put into consideration numerous factors before you proceed. While some solar thermal systems are suitable for use at home, there are also some that are suitable for businesses or organizations which normally requires a big amount of hot water like hotels, restaurants, schools, hospitals and many more. You’ll also find some types available in the market that are suitable for communities to satisfy communal hot water demands.

It should, however, be noted that solar thermal systems do not have the capacity to produce all the hot water demand of a house. In the UK, an average household will need an annual water heating of between 3000kWh to 5000kWh. Whereas, a solar thermal system is only able to meet about 40 percent to 60 percent of this demand.

With that in mind, it’s also worth noting that during the summer months when the solar radiation is at its peak and hot water demand is relatively lower when compared to other seasons, a solar thermal system may be able to provide all of your household’s hot water needs. This implies that during this period you may not find the need to operate your boiler at all. However, during winter or colder months, when you have a higher hot water demands in contrary to a lower solar radiation, a solar thermal system will only be able to take care of about 20 percent of your household’s hot water needs. And that ultimately implies that during this period, you’ll need to rely more on a alternative or backup source of heat like gas, coal, electricity, oil or LPG.

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.

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.

There are a few trusted companies in the UK that make solar panels. While there are other solar thermal panels out there that are made by Chinese and American companies, we’ll focus on the brands with a longstanding presence in the UK since these are the panels MCS-registered solar companies are likely to recommend to you.

Viessmann, Worcester Bosch, Solar UK and Dimplex make some of the best solar thermal panels in the UK. Dimplex and Viessmann offer both flat plate and evacuated tube solar panels, while Solar UK only offers evacuated tubes. Worcester Bosch’s Greenskies range are all flat plate collectors. Viessmann’s panels come with a 5-year warranty, while Worcester Bosch and Dimplex offer extensive 10-year warranties. However, Solar UK offer a comprehensive 25-year warranty and guarantee that the panels will deliver the same level of performance for 25 years!

We’d recommend choosing evacuated tube solar thermal panels because they are the most efficient. While there won’t be much difference between evacuated tubes and flat plates in the summer, in the winter evacuated tubes are much better at taking heat from the sun than flat plates. Since our winters are long and cold with few daylight hours, we think it makes sense to go with evacuated tubes. However, if your priority is looks over maximising efficiency, you might want to choose flat plate collectors since they sit flat on the roof and look more like solar PV panels, whereas the evacuated tubes will stick 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.