11.8.3 Photovoltaic Solar Electricity

closeddate_range22 Dec, 2020, 9:00am - 12 Mar, 2021, 5:00pm
​​​​​​11.8.3 Photovoltaic Solar Electricity

The production of solar electricity relies heavily on active solar technology. The most commonly encountered system for solar electricity production is solar photovoltaic. Solar photovoltaics (commonly referred to as "PV") is the term given to the conversion of light energy (irradiance) to electricity and also describes the active solar technology (Solar photovoltaic systems) which produces electricity from solar radiation using solar cells joined together in panels called PV modules.

Photovoltaic Solar Electricity can be generated at various scales, ranging from domestic to utility scale solar PV (USSPV). Such utility Scale Solar Photovoltaic arrays are connected to the National Grid and are generally referred to as “solar farms”.

Although there is considerable variation in appearance, many solar modules are dark in colour and have low reflective properties. They are generally placed on the ground in arrays facing the sun, which allows for grazing underneath, or are fitted to buildings and in particular on south facing roofs. With improvements in technology, solar panels are becoming increasingly efficient and cost effective.  

On average, 1 sq. m of silicon solar panels will generate 200W of power on a clear sunny day[1]. That’s enough to power a laptop computer. A home solar PV system sized at 20 sq. m (3kW) and well located would generate around 2,600kWh of electricity a year. That is over 40% of the average annual electricity demand of an Irish home. Solar PV systems will still function on overcast days in Ireland although not at their maximum rated capacity.

Due to high levels of irradiance, according to SolarGIS, County Kilkenny has the potential to generate between 950 to 1000kWh/m2, which, together with Counties Wexford and Waterford, makes Kilkenny a very attractive location for utility scale solar farms.  Standalone polar PV needs to be stored and for this purpose storage batteries are generally used in domestic and commercial scale solar installations to store the energy to match the domestic or network demand.

Solar Thermal (STE) power plants use solar radiation to heat a fluid to high temperatures. The technology is applied in domestic settings (i.e. to heat water) and at a utility scale, where heated fluid can transfer to water in order to create steam to drive turbines.


[1] According to the SEAI website.