Solar Panels/Photovoltaics

What are Solar Panels?

The term ‘solar panel’ is often used for both panels that:

·     Produce Hot water (Thermal Collectors)

·     Produce Electricity (Photo Voltaics)

Solar Thermal Collectors

Solar panels that produce hot water are known as solar thermal collectors or solar hot water collectors.

Photo Voltaics

Solar panels that produce electricity are known as solar photovoltaic (PV) modules. These panels generate DC electricity when exposed to light.

There are two groups of technologies which generate electricity from light which are as follows:

• Solar photovoltaics (solar PV): This is the most common solar technologiy worldwide and the most suited to Ireland. They are also the fastest growing in terms of installed capacity.
• Concentrated Solar Power (CSP): This technology produces electricity by focussing sunlight to produce heat and drive an engine connected to an electrical generator. These are more common in countries with year long sunshine.

How do Photovoltaics (PV) work?

Semiconductor technologies which can generate electricity when exposed to visible light these are called Photovoltaic (PV) materials.

Solar PV technologies use a wide number a of semiconductor materials with silicon being the most common but other semiconductor technologies are advancing. 

Applications of PV technology?

Solar PV products have a number of different uses these include:

• Solar panels or modules which are the best known solar PV products. These would be commonly seen on rooftops and in ‘solar farms’ . These have been mass manufactured for over 25 years to produce electricity.
• Building Integrated Photovoltaics (BIPV). A number of building products have been produced using these materials such as roof tiles, glass or cladding with solar PV materials embedded within them which generate electricity.
• Consumer electronics. A number of consumer products have been developed with Solar PV materials integrated into them so that they can produce their own power.

How much Energy does PV produce?

A home solar PV system sized at 20 sq. m (~3kW) and well located (south facing) would generate around 2,600kWh of electricity a year. That is generally 40% of the average annual electricity demand of an Irish home.

Do Solar PV work on cloudy/overcast days?

Solar PV systems will still function on overcast days in Ireland although not at their maximum rated capacity. The main factors that affect the efficiency of the Solar PVs are as follows:

• The type of system chosen
• The size of the system- larger the better generally
• The geographical location of the dwelling
• The direction in which the panels are installed (ideally South Facing)

Should I invest in a Solar PV System?

If you are going to invest in Solar PV, there are a number of critical things to ensure you are installing the right system for your home, community or business which include:

• Finding the right installer. We suggest getting a number of quotes. Note that there are currently no formal qualifications that installers must have.
• The connection of the solar system must be carried out by a Registered Electrical Contractor (see a local list of RECI contractors). SEAI have provided a list installers who have received accredited training.Renewable Installers Register 
• Choose the right equipment. This is a long term investment so we would advise dependent on budget to get the best products on the market with the best efficiency.

The equipment generally includes:

• Solar modules
• An inverter, which converts electricity from direct current (DC) to alternating current (AC)
• A mounting system for the roof or ground
• There are also battery systems or 'diverter switches' for storing excess energy

The SEAI have a register the Triple E Register for solar PV products that meet a minimum performance criteria, including energy efficiency.

Do I need Planning for erecting PVs?

You are not required to obtain planning if you meet the following criteria:

• Solar PV systems installed on a dwelling that are under 12 sq. m (and represent less than 50% of the total roof area) are exempt from planning.
• Solar PV systems installed on an industrial building or commercial building that are under 50 sqm (and represent less than 50% of the total roof area) are exempt from planning. 

In general larger solar PV systems in homes and businesses will require planning permission. We recommend you speak with your local planning authority to understand the requirements.