City Hall

Organisation:

London Climate Change Agency

Size:

Large

Location:

City Hall, Southwark

Aim:

To demonstrate through ‘showing by doing’ how an iconic building in a landmark location can be retrofitted to incorporate a decentralised energy system using low carbon technologies.

Savings:

Generation of 50,000kWh of electricity per year and saving 28,000 kg of CO2 emissions per year.

How the London Climate Change Agency (LCCA) made a difference

The impressive City Hall building stands on the bank of the Thames and is home to the Mayor and the Greater London Authority (GLA). It is a London landmark and in use throughout the year.

To reduce carbon emissions, the LCCA installed an electrical energy system for the Greater London Authority (GLA) made up of 617 monocrystalline photovoltaic panels and 46 bespoke glass-glass laminate panels, without disrupting day-to-day activities.

Southwark Borough Council and Foster & Partners, the planners and the architects of the building respectively, requested that any new technology preserve the aesthetic of the building and surroundings.

This created an exciting design challenge for installers Solar Technology and PV panel producers Romag and required the development of new and innovative approaches in photovoltaic panel manufacturing.

The photovoltaic panels were arranged into concentric circles around the unique domed roof. Normal photovoltaic panels are rectangular and come in an aluminium frame. However, to cover the domed roof while still retaining the existing mosaic effect, the panels were made-to-measure trapezoidal and bare unframed glass. In total nine different shaped/sized panels were designed to suit the roof.

To ensure that the panels blended into the building’s design and surroundings, Romag developed a process of using black coloured film to line the back of the panels.

They also constructed unique, multi-sized glass-glass laminated panels for the shadowing device on the top floor of City Hall. This included a 1.9m x 3m panel, the largest currently installed in the UK.

The hard work and close collaboration between all involved parties paid off.

The new system has a total installed capacity of 67kWp from an active cell area of 417m2. It can generate 50,000kWh electricity per year, offsetting 28 tonnes CO2 emissions in the same period .

And by involving all stake-holders in an early stage, the existing insurance liabilities of the building were preserved.

The project stands as an excellent example of how an organisation can implement renewable energy technologies for occupiers or building owners.

“The completion of the installation of Photovoltaic cells on the roof of City Hall finishes the building as originally designed. This would not have been possible without the direct help and support that we have enjoyed from the Mayor and the GLA, planners at Southwark, the LCCA and our clients at More London. The installation is the most apparent and physical manifestation of the building’s sustainable design agenda. We totally support the Mayor in his goals and we hope that City Hall will act as an inspiration to others designing sustainable buildings in our capital.” – Grant Brooker, Executive Director, Foster + Partners

Live system performance is available on the web, check: www.sunnyportal.com or www.lcca.co.uk