Going solar at City Hall

Why going solar is good

Solar cells provide an efficient and economic way of generating energy. Photovoltaic technology is safe, proven and does not release any emissions that contribute to climate change.

The benefits of photovoltaic technology include:

• a dedicated, clean and safe power source providing free and inexhaustible energy from the sun
• no moving parts, therefore silent operation
• no CO2 emissions given off
• minimal maintenance
• no toxic emissions, saving the environment
• a positive step towards a sustainable future.

How solar power works

Photovoltaic (PV) cells work by using solar cells to convert light from the sun into electricity.

The sun produces energy in the form of both heat and light. It is the light energy, and not the heat from the sun, that creates the power source in PV systems. This means that, even in regions where the daytime sky is frequently overcast, there is still ample light for electricity production using a PV system.

A PV cell consists of two or more thin layers of semi-conducting material, most commonly silicon. When the silicon is exposed to light, electrical charges are generated and this can be conducted away by metal contacts as direct current (DC).

The electrical output from a single cell is small, so multiple cells are connected together to form a panel. The PV panel is the principal building block of a PV system and any number can be connected together to give the desired electrical output. PV systems can be used to power ordinary electrical equipment such as computers and lighting.

Funding the project

The City Hall solar power project was funded and implemented by the London Climate Change Agency. This agency was set up by the Mayor in 2006 to tackle climate change by promoting and delivering decentralised and renewable energy projects. The project has also received a grant from the Department of Trade and Industry Major Photovoltaic Demonstration Programme, which is managed by the Energy Saving Trust.