Typical Solar Panel Installation
A 40 square metre roof in Ireland will typically receive in excess of 37,000 kWh of solar irradiation annually. A typical family of four may use approximately 3000 kWh per year to heat their domestic hot water and perhaps an additional 18,000 kWh for space heating (assuming a building heat loss of 100W/m2). A solar thermal system has usually an economic and practical design limit of providing about 60% of the hot water in the house. Typically 5-6 square metres of flat-plate collector will be used to supply this energy and any additional system losses, with an effective output of approximately 350 kWh for each metre squared of the collector. To reach 60% percentage coverage of the domestic demand requires both a sympathetic use of the auxiliary heating by the householder and a degree of management of the hot water demand.