Solar Energy

Solar radiation drives all natural cycles and processes on earth such as rain, wind, photosynthesis, ocean currents and several others that are important for life.

From the very beginning of life, the overall world energy need has been based on solar energy. All fossil fuels such as oil, gas and coal are a result of solar energy.

The energy yield from the sun is collosal.
If all the sun's energy acting on the earth’s surface over a 15 minute period could be captured, it would provide more than enough energy to power Mankind 24/7 for a whole year.

On a more local level , the amount of energy that can be absorbed at a given place, is measured in kilowatt hours per square metres or kWh / sqm. 

In Northern Europe, the maximum annual energy levels are 1,100 kWh / sqm, with Rosslare, Co Wexford seeing levels of 990 kWh / sqm and London seeing levels of 943 kWh / sqm. So in fact the use of solar energy in Ireland is actually pretty good, far greater than most people imagine.

In the summer, when items such as car bodies are often too hot to touch, we become aware of the sun's heat. However, even in the spring and autumn and on clear winter days we receive very usable amounts of solar energy.

The average property requires approximately 3,000 kWh per year for domestic water heating.

The map shows the total average solar radiation falling on one square metre surface inclined at 30° to the horizontal, measured in kilowatt hours.

These figures bring out the remarkable fact that the amount of solar energy falling on the total roof area of an average house is many times that required to provide all its heating and hot water.

However, there is a large difference between the radiation available in the summer and that available in winter.  Active solar heating systems will typically convert 40 to 50% of the annual solar energy falling on the solar collectors into useful heated water.

In Ireland and UK, diffused radiation makes up between 40% (May) to 80% (December) of the total solar energy available in a year.