Return on investment solar panels

Solar panels cost and yield

On average, the efficiency of solar panels varies between 15 and 22%. At Soly, the efficiency of solar panels is at 21.27%. In practice, this means that 21.27% of all sunlight can be converted into energy by solar panels. The calculation of the efficiency is determined based on the area, peak power and slope angle of the solar panels on the roof, among other factors.

Why is solar panel efficiency important?
The efficiency of solar panels directly relates to the cost and yield of the solar system. This allows for a good prediction of the payback period of the solar panels. Yield also demonstrates the efficiency of a solar panel. The greater the efficiency of a solar panel, the less space on the roof is needed to produce a certain amount of yield. The industry’s challenge is to produce solar modules with a higher efficiency without the dimensions of the solar panel or the amount of solar cells increasing, aiming of course to maximise the amount of yield you can get out of your roof.

Highest return from solar panels

If you do not have solar panels yet, but are thinking about them? Or do you already have solar panels on the roof, and would like to enjoy the highest return? Read our tips to ensure yourself the highest return from solar panels.

✓ Type of solar panel and microinverter
There are dozens of solar panel manufacturers worldwide, and a much larger number of different types of solar panels. When choosing solar panels, pay particular attention to the relationship between the size and peak power (Watt peak) of solar panels, combined with the space on your roof. Making the right choice can increase the annual yield of solar panels by a lot.

Because the microinverter is an essential part of the system, it is recommended that you look at this carefully as well.

✓ Orientation and inclination
Generating the highest yield from solar panels sometimes depends on the details. Make the right choice for the orientation and inclination of the system. South-facing solar panels will ensure that your system generates the most solar energy, while the ideal solar panel inclination should be between 30 and 35 degrees.

✓ Shadows and dirt
Limiting factors for your solar panels are shadows falling on the panels and a layer of dirt. Therefore, make sure you have the solar system installed on a roof where there are few limiting factors such as trees or other buildings in the immediate vicinity. If you encounter a dirty layer on the panels, for example due to Sahara sand, you can choose to wipe the panels with a dry and clean cloth.

✓ Lifespan
The lifespan of solar panels is quite long. In practice, at least 25 years, without the solar system losing its original quality. Nevertheless, the efficiency of the solar system will decrease slightly over time, resulting in a slightly lower yield. This in itself is not a surprise, but it is good to keep in mind when calculating the expected efficiency of solar panels, now and in 25 years.

✓ Weather conditions
One factor we unfortunately have no influence over in the UK is the weather. In the UK, we encounter everything every year: rain, sun, clouds, wind, snow, hail, high and low temperatures. That means your solar panels are exposed to all these external factors, and the yield can never be optimal in practice, as it is in test conditions.