Solar Energy

The production of hot water for various processes is a big energy consumer for many businesses. Solar water heating is an efficient and reliable technology that converts the suns thermal radiation into a useable heat source. In Waterford a horizontal surface of 1m² receives an average of between 1,000-1,200kWh of solar thermal radiation per year, which is equivalent to 120 litres of oil. As this system utilises the thermal radiation of the sun is does not require direct sun light to work, in Ireland the ratio is roughly 40% direct sunlight, 60% indirect. While a solar water heating system alone cannot provide for all a buildings heat requirements all year round, a properly sized installation can significantly reduce yearly hot water costs.

Suitability

Solar thermal technology is very straight forward and is suitable to almost any building with a flat roof, or a roof with a southerly aspect. The roof area is used to attach the solar collectors, of which there are two main types;

• Flat plate collectors, suited for hot water and low temperature heating. Efficiency of 40%.
• Evacuated tube collectors are more efficient with higher water temperature and provide solar water heating when solar radiation is less intense. Typical efficiency of 60%.

Heat generated by a solar panel is transferred to a large storage cylinder (or calorifier), where the hot water is stored until usage. During the winter period a conventional heating system, such as a boiler, will provide an alternative source of heat to the cylinder to meet hot water requirements. Typically solar water heating can be used to complement any form of heating technology and is ideally suited to businesses that have a large hot water demand.

Solar Photo Voltaic (PV)

The photovoltaic (PV) process converts sunlight directly into electricity. The equipment required for this process has no moving parts, and results in no emissions or noise. PV solar panels (or cells) have a lifespan of 25-30 years and require very little maintenance which in some cases makes their longer payback period more acceptable. Like the wind turbines, solar PV systems are almost always a “grid tied” installation, requiring an AC rectifier and smart metre.

Suitability

Best suited to buildings with unused and exposed roof space, either flat roofs, or roofs with a southerly aspect. Solar PV panels are relatively simple to retro fit, as once the panel are installed on the roof the rest of the installation is wiring from the panels to the electrical distribution panel and smart metre.