General FAQs

1. What are solar panels?

The term ‘solar panel’ can refer to a wide range of solar technologies. It is often used interchangeably between the panels that generate electricity and those that generate heat. Solar panels which produce electricity are referred to in the industry as ‘solar photovoltaic (PV) modules.’ These are panels made from materials which generate DC electricity when exposed to light. When considering purchasing solar panels it is important to consider whether you would like a system which generates electricity (solar PV panels) or a system which heats water (solar thermal panels). The questions in this document are all in relation to the electricity generating panels.

2. What different types of solar PV panels exist?

There are a variety of different solar PV technologies and products. The performance and cost of different products varies greatly.

The most common solar PV technologies are:

Mono-crystalline silicon panels: typically the most efficient commercial solar panels at converting light into electricity
Multi-crystalline silicon panels: typically slightly less efficient than mono-crystalline panels but often less expensive
Thin film panels: this encompasses a range of technologies (including those made from cadmium telluride (CdTe), copper indium gallium diselenide (CIGS) and amorphous silicon (aSi)). These technologies are not as widely deployed but are often favoured because of their appealing appearance.
Silicon-based solar panels are by far the most commonly deployed, accounting for over 90% of the global market.

When considering installing solar PV panels on your roof you will typically be limited to the products which individual installers offer. Be sure to ask to see the technical specification for the solar panels they are offering.

3. How much electricity will solar panels generate?

The amount of electricity generated annually will depend on a range of factors including the hardware chosen, size of system, the geographical location and the direction in which the panels are installed. With the most common silicon solar panels typically 1 sq. m of panels will generate ~150W of power on a clear sunny day (that’s enough to power a laptop computer). A home solar PV system sized at 20 sq. m (~3kW) would generate around 2,600kWh of electricity a year if well-located, over 40% of the typical annual electricity demand of an Irish home.

4. Do solar panels work in Ireland?

Yes, solar PV systems will still generate electricity when there is daylight, so they will still function on overcast days in Ireland. In these conditions they will not be able to produce power at their maximum rated capacity (the figure in kilowatts (kW)), rather at some fraction of this figure. Solar panels will perform at their best in direct sunlight and therefore solar PV systems in Ireland will typically produce less than other, sunnier countries such as Spain. As mentioned above, a home solar PV system sized at 20 sq. m (~3kW) would generate around 2,600kWh of electricity a year if welllocated, over 40% of the typical annual electricity demand of an Irish home.

5. How much do solar panels cost?

The cost of purchasing and installing solar panels has come down considerably over the last 10 years. The cost of a solar PV system depends on a range of factors including the hardware chosen, size of system, accessibility of the roof or site, and the installer used. Broadly speaking home PV systems should range from around €1,500 – €2,000 per kW installed (ex-VAT), but prices will vary depending on the factors mentioned above.

6. Where are solar panels manufactured?

Most solar panels are manufactured in Asia (primarily in China and Taiwan) but there are also some European and North American manufacturers. The components for solar panels and other hardware used in the installation come from all around the world.