Blackfriars Bridge, a Victorian rail bridge in the heart of London, is now well on its way to becoming the biggest solar array in the city and the world's largest solar bridge. When the installation is complete, the roof of the new Blackfriars railway station will be home to over 6,000 square meters (64,583 sq.ft.) of solar panels, satisfying half of the station's power needs.

We recently featured a two mile stretch of rail tunnel with 16,000 solar panels on the roof, providing power to signaling, lighting, and heating of railway stations, and also to some of the trains using the Belgian rail network.

Now, Blackfriars Bridge has started to have over 4,400 high-efficiency Sanyo HIT photovoltaic panels installed on its newly-built roof by London-based Solarcentury and engineers from Jacobs. Blackfriars spans the River Thames, and was originally built during the age of steam in 1886.

The new Blackfriars Station is currently being redeveloped as part of a Network Rail Thameslink program upgrade (with funding from the Department for Transport's safety and environment fund), which aims to have longer trains - meaning more seats for commuters - running from Bedford to Brighton via London. The solar installation will generate a claimed 900,000kWh of electricity every year, and will be joined by other energy-saving measures such as rain harvesting systems and sun pipes for natural lighting.