Produce your own electricity

Solar cells provide you with electricity
Solar cells are a simple way of producing renewable energy, and they do not require much maintenance. The main purpose of solar cells is to reduce CO2 emissions, but they can also reduce your electricity bill.

How much does it cost?
Based on the current price of electricity and the cost of the solar cells, the repayment term on a solar cell array is 12-15 years depending on the size of the system. So this requires an investment with a long payback time.

However, the payback time is decreasing for several reasons. Systems are becoming cheaper, solar cells are getting better, and energy prices are rising, so savings will be greater by having a system. The benefits of having solar cells are improving all the time.

How much can you save?
The power generated by solar cells can help reduce your electricity bill, but the amount saved depends on the output of the system, and the price of electricity.

A typical solar cell array of 10-15 m2 can shrink your electricity bill by about EUR 260 a year, reducing your carbon footprint by 0.6 tons

The CO2 savings achieved by solar cells come with no strings attached. However, you should factor the cost of the system into the financial savings.

How long does a system last?
A solar cell system can produce electricity over a number of years with virtually no maintenance. The lifetime of solar cells varies and their output falls the older they get. So check the guarantee supplied by the producer.

Some producers sell their solar cell modules with the output guaranteed for 25 years. Most manufacturers guarantee that after 12 years and 6 months a solar cell module will still deliver 90% of the output guaranteed at the time of delivery, and at least 80% after 25 years. So the output will fall by a maximum of 20% after 25 years.

Solar cells are sold in modules
Solar cells for homes are sold in modules which are easy to install and use. The modules are made up of groups of solar cells connected together. Depending on the type and quality, commercially available solar cells currently utilise only about 8-21% of the sun's energy, but their efficiency is improving all the time.

Location and size
Solar cells are typically mounted on the roof, but it is also possible to integrate solar cells into roofs, building facades, or into window panes. It makes sense to integrate them if you are in the process of refurbishing or adding to an existing building anyway.

You will get the most benefit from solar cells if they are not in shadow during the daytime, and face south at an angle of 45 degrees. The size of a solar cell system depends on 2 things:

1. What proportion of a home's electricity consumption needs to be covered.
2. What size of system you are able to install – financially and practically.

Domestic solar cell systems are typically 10-15 m2.

How solar cells work
Solar cells convert sunlight into electricity which can be used for lighting and electric appliances in your home. The technology is maintenance free with no mechanical components that can break.

Solar cells convert the power of the sun into electricity using the so-called photovoltaic effect. Most solar cells use the semiconductor silicon as the basis of the process. Solar cells produce DC current as opposed to AC, so it needs to be transformed by passing the current through an inverter before it can be used to power lights and domestic appliances in your home.

> News and information on solar energy from the Danish Energy Agency (external link only in Danish)

> Read more about solar cells from the Danish Technological Institute (external only in Danish)