Introduction

Direct solar radiation can be used in two main ways: solar heating; photovoltaics. Solar heating is typically employed by heating a working fluid (water) in a closed system and then utilising this heat in a domestic or commercial property.

Issues surrounding both solar techniques lie with the poor efficiencies giving rise to a large area requirement to locate the devices to develop any useful levels of power. Lifetime and service issues (such as ensuring a clean outer surface) remain.

Photovoltaic Panels

Photovoltaic (PV) panels turn sunlight into Direct Current (DC) electricity, and can be used to provide electricity.

Feasibility questions to ask before installing PV panels:

• Is there good direct sunlight exposure?
• Is there sufficient roof space available?
• Is the sunlight restricted at any point for a long period of time?

Reasons for installing PV panels:

• Maintenance is minimal
• Can be building-integrated which can minimise aesthetics effects, reducing costs

Additional information:

• Costs – Solar PV systems typically cost between £8,000 and £18,000
• Funding – Sizeable grants are available from the Energy Saving Trust which can reduce the cost by up to 50%.

Solar Thermal

Solar hot water systems use the sun’s solar radiation to pre-heat water on its way to a water heater, minimising the amount of heating that this appliance needs to do.

A performance calculator for grid- connected PV Systems is available from the following link: http://rredc.nrel.gov/solar