There have been numerous ideas and schemes for lighting the Thames over the years, but none on a scale as ambitious as Illuminated River. From Albert Bridge in the west to Tower Bridge in the east, Illuminated River aims to light the bridges of central London, enhancing their architectural qualities while creating a unique opportunity to think about how light is used in the public realm around the River Thames.

With the backing of the Mayor of London and City of London Corporation, the Illuminated River International Design Competition was launched in June 2016. More than 100 multi-disciplinary teams entered the open competition, nearly half of them from overseas. In September, a shortlist of six was invited to submit a concept design for lighting four individual bridges (Chelsea, London, Waterloo and Westminster) along with an overarching masterplan for the main road, rail and pedestrian bridges between Albert and Tower bridges. The winners, American light artist Leo Villareal and British architects Lifschutz Davidson Sandilands, were announced in early December.

Light as a medium for public art fascinates artists and audiences across the world. And now that new lighting technology can dramatically reduce energy consumption, London has the opportunity to reclaim the river after dark. The Illuminated River is more than a lighting project for some of London’s key bridges: it is an opportunity to improve the wider public realm around the bridges, enhancing their links with the surrounding streets to create a pleasant, safe and walkable environment, to change the interaction between the city and the river for the long term. The project offers the rarest of opportunities: to influence the look, identity and experience of one of the world’s greatest cities.

Illuminated River also allows us to address issues of increasing lighting pollution and energy consumption in the city. The lighting of many of the bridges needs updating: they have accumulated a variety of lighting elements over the years, some of which create glare and light spillage. With more subtle lamps and the removal of excessive fittings, we can strip back the bridges to reveal their architectural beauty.

By replacing out-of-date and inefficient metal halide and fluorescent lamps with the latest LED technology, we should be able to reduce energy consumption per bridge by as much as 50–70%, resulting in significant cost reductions for the local authorities that own many of the bridges. Newer, longer-lasting lamps won’t need replacing for many years, reducing long-term maintenance costs. The project also lends itself to exploration of the use of renewable energy, partly generated by the river, or from other sources. The hope is to encourage greater understanding of the potential of new, greener energy.

This is an ideal moment to be refocusing attention on the river and improving its relationship with Londoners and the rest of the city. For a long time, London turned its back on the Thames: it was hard for the public to access it or walk along its banks. Over the last decade, London has emphasised the potential of the river for cultural activity and leisure, with the resurgence of the South Bank, and with major new infrastructure projects, such as Thames Tideway, designed to create new public spaces on the foreshore. The Illuminated River project will work with other initiatives to put the Thames back at the heart of the city.

The Illuminated River seeks to celebrate light – but that doesn’t mean not appreciating darkness. The winning concept will need to be flexible enough to be adapted or turned off in the early hours, or at specific times of year in sections of the river where residents may be affected; or to respect the migratory, feeding or breeding habits of the fauna of the river; or to celebrate darkness itself. And Illuminated River will complement and work with other celebrations of key moments and events in the city.

The winning scheme will be developed into a final detailed design after extensive consultation and discussion with all the stakeholders and communities along the river and beyond. We are acutely aware that the river is a unique natural as well as a built environment and that excessive night-time lighting can adversely affect the balance of the delicate ecosystems around and within it. We will be working hard to ensure that we do not affect the habitats of bats, fish, birds and other fauna and flora – and, indeed, we will be taking every opportunity to find ways to improve them.

This is the start of an exciting and stimulating dialogue about the future of the Thames, our public realm and the role of public lighting in London. There is much to learn in order to create a project that not only addresses environmental issues but also provides a positive contribution to the night-time economy, demonstrating that London is open for visitors and Londoners alike.