Solar Myths Explained

Will the panels damage my roof?

The most common way of installing panels is an ‘on-roof’ system where the panels sit above the tiles on rails supported by hooks screwed into the rafters. This type of system doesn’t interfere with the weather proofing of the roof since the tiles remain in their original positions.

There are some on-roof fixings where the hooks fix onto the battens alone rather than onto the rafters. Some installers like this system because it is cheap and very fast to install, however most structural engineers have strong reservations about the robustness of this design.

Surely there isn't enough sun in the UK for solar panels?

Whilst there is obviously more sun in Spain than over here, we actually get a phenomenal amount of energy from the sun in the UK. The amount of energy we get from the sun is in fact larger than any other energy source available to us. If you install a solar energy system on your home it will typically produce over 50% of the electricity that your house consumes.

Do I only get paid for the electricity I sell back to the grid?

The Government’s Feed-in Tariff programme obliges energy companies to pay you for every unit of electricity that the panels generate, regardless of whether you use that energy or not. In domestic systems, the amount of energy fed back to the grid is currently not monitored. This means it is in your best interests to use as much solar energy as you can, as you will still be paid the full amount for what’s generated.

Will it increase the value of my home?

Solar panels represent a secure income stream that’s tax free and linked to inflation. If you own the panels then you can just add their value to the price of your home. Engensa will provide you with a valuation of your solar panel system based on its actual performance to-date taking into account the future revenues it will generate. This will allow you to get a return on your investment. Solar panels installed before April 2012 will likely have a high value in the market since the Feed-in Tariff level is expected to be reduced significantly.

If you have free solar panels under a roof rental scheme such as Engensa’s SunRoof programme, then anecdotal evidence shows this increases the value of your home since it will have reduced energy bills and a higher energy rating.

I can't believe the parts will last for 25 years?

Around the world, investors are installing solar panels in vast quantities (over 80 million were installed in 2010) which is a testament to the confidence in their reliability. All solar panels sold in the UK have gone through very rigorous testing. The IEC testing protocol involves a whole host of ‘accelerated lifetime tests’ for solar panels that try to simulate 25 years wear and tear in a short space of time (a bit like torture). These included the ‘salt-bath test’ (where panels are dunked in a bath of warm salty water with a high voltage applied), ‘thermal cycling’ (-20C to 80C for two weeks), the ‘humidity-freeze’ test (the ice shows up any cracks) and the hail stone test (firing a ball of ice at 50 metres per second). If your panels can get through these tests then they have a good chance of lasting the test of time.

What parts do I need to replace?

The panels shouldn’t need replacing but you may need to replace the inverter once. The inverter is a key component of the system that takes the power from the solar panels and turns it into mains frequency electricity that can be used in the house. You can take out an extended warranty but its generally considered better not to bother since inverter prices will fall dramatically over the next 10 years.

Do the panels need servicing?

The panels themselves shouldn’t need mending, but they are likely to require some cleaning. As solar panels become more common, many window cleaners will branch out into cleaning solar panels. Using a ladder and a soft mop (with no detergent) the panels can easily be cleaned. How often depends on the location. If there is a lot of dust or other dirt around then they may need cleaning every few months, if not they may just need an annual wipe down. Make sure the panels are installed at an angle to allow for water run-off.

What happens if the installation company goes bust?

Installers generally give installation and labour warranties of 2-5 years during which time they are responsible for any maintenance required free of charge. Its possible to buy a third party warranty in case the company goes bust during this time, but its generally better to make your own assessment of the companies credibility and track record. Use reputable sites such as YouGen.co.uk to check reviews of installers. Luckily solar PV panels require relatively little maintenance so unlike solar hot water panels, so if the company does go out of business you are unlikely to find yourself without a working system.

How do I know if my system is working as well as it can?

Gathering performance data from your PV system is very important. As standard, all systems come with a generation meter. Although this tells you how much energy your panels have generated, it doesn’t record the data meaning its very hard to see how your system is doing day-to-day. Some installers like Engensa offer remote monitoring which allows you to view the instantaneous and historical performance of your system in a web browser. This means you can quickly get a good idea of the system’s performance after it has been installed. Remote monitoring is also useful to provide your Feed-in Tariff provider with a meter reading every quarter if you happen to be away from home. Ask your installer if they can compare the performance of your system with other systems they have installed in the area, good installers will provide you with a periodic report on your systems performance.

How do I know if my roof is strong enough to hold the panels?

Its very important to make sure that your installer knows the building regulations around structural requirements. Ensuring the panels can withstand wind uplift is very important as some roofs need to be strengthened before panels can be safely fixed to them. You should be weary of any installer that doesn’t provide a structural opinion. Ideally the installer will have contacted local building control to find out their specific requirements for Part A (structural) building regulations and arrange for calculations to be done by a qualified structural engineer before your installation. Failure to comply with Part A building regulations risks a fine of up to £5,000 pounds and can cause problems when a property is sold.