20 Fenchurch Street: Sustainability in an Urban Context


Neil Pennell, Head of Engineering and Design, discusses how Land Securities has embraced the City’s need for efficient design and eco-friendly power generation.

When it comes to sustainability, urban environments pose a range of unique challenges to developers. Due to constrained development sites, the close proximity of surrounding buildings and noise and air quality concerns a central city location does not lend itself to large-scale energy generation through the use of solar photovoltaics, wind power, biomass heating or gas fuelled Combined Heat and Power Plant (CHP). However Land Securities is committed to finding sustainable solutions wherever possible.

When faced with the challenge of reducing the energy footprint at One New Change, in the City of London, we used a ground-source energy system to produce low carbon heating and cooling for the building. This site had the advantage of a large floor area but was restricted in height to meet the St Paul’s protected view requirements. When designing 20 Fenchurch Street the limited ground space dictated that a high rise building would be needed to fully realise the value of the site. It became apparent that, due to the building’s relatively small footprint, a system like the one at One New Change would not make a meaningful contribution to reducing the building’s primary energy needs.

The circumstances called for a truly innovative solution. Hence hydrogen fuel-cell technology, similar to that originally developed for the Apollo and Shuttle space missions, was installed at 20 Fenchurch Street. The 300kWe stationary fuel cell, the first installed in the City of London, is fuelled by natural gas and integrated with an absorption chiller to produce cooling for the building when the demand for heat is low. Through the production of low-carbon cooling, heating and electricity, it will help to reduce carbon emissions from the building by 6-7%. Conservatively, we estimate that the fuel cell will reduce the carbon dioxide emissions of the building by at least 270 tonnes per annum.

The fuel cell essentially produces the same outputs as a conventional CHP plant but instead of burning gas in a noisy reciprocating engine with the typical products of combustion in the flue gases to create electricity and heat, it uses a chemical reaction. The fuel cell is a highly efficient producer of electricity and you end up with a very benign exhaust of hot air and water vapour, so it's a very low pollution solution and it's also incredibly quiet, the perfect solution for a city centre building power plant.

So why doesn’t everybody install them in their buildings? The answer at the moment is the high cost when compared with more traditional solutions. However this is changing and the use of stationary fuel cells is increasing year on year with significant investments being made in the US, Japan, Korea and Germany.

The installation of this eco-friendly source of energy, combined with an energy-efficient building design, enabled 20 Fenchurch to secure a BREEAM excellent rating. The use of innovative fuel cell technology in the real estate sector is also fully supported by the Mayor of London whose policies on climate change mitigation recognise the important contribution hydrogen based technology will play in the future. For Land Securities it demonstrates our long-term commitment to sustainable development and to be an industry leader in the use of new and innovative technology.

This blog was originally published here.