Plans to install London Stadium’s solar membrane is an important landmark for renewables in the capital, but more needs to be done to drive adoption if we are to hit net zero targets, says Anthony Maguire, director of Longevity Power
The 2012 Olympics stadium will be wrapped in a solar membrane as part of a drive to reduce its carbon emissions, according to recent reports. The project is likely to cost £4m over the first two years and should pay for itself in around five years. The stadium’s owner, the London Legacy Development Corporation (LLDC), projects that the building could start generating energy by end of 2024.
While the inclusion of on-site renewable energy sources on any iconic London building is encouraging, it’s important we dig deeper to understand its true impact.
A contract for the project’s installation states that a key driver is to significantly reduce carbon emissions, in line with London’s 2030 net zero carbon commitment.
So, how much of an impact could such an installation have?
London Stadium’s solar membrane could produce a sizeable energy surplus
According to a statement published in early February 2023, the stadium currently consumes 12,000 kWh of electricity per year.
In addition to assessing the potential for solar energy on the stadium’s roof (24,000 m2), the LLDC is considering the opportunity to install battery storage for when surplus electricity is generated.
While this information is not provided in the statement, a back-of-the-envelope calculation indicates that the London Stadium might be able to support an installation size of around 1.5 MWp, which would generate around 1,300 kWh of clean power a year – just over 10% of the building’s annual requirements.
We can assume that, even with the presence of a battery storage system, 10%-20% of this electricity will be exported back to the grid. This might seem counterintuitive given that the solar system is generating a relatively small proportion of the stadium’s required electricity demand, but it is down to the misalignment between the building’s consumption profile and the PV system’s generation profile.
Very simply, football stadiums are likely to use most power during evening events when the floodlights are in use. The consumption of the stadium on weekdays during the summer months is unlikely to be that high, and it is during these periods when the PV system will produce a large quantity of excess power.
With the technological advancements and cost declines associated with mono and poly-crystalline solar PV panels, it is interesting that the proposed PV system at the London Stadium references a “solar membrane”. This may simply be semantics, or it may suggest that the building is unable to withstand the weight associated with conventional solar panels and that they are opting for a building-integrated PV (BIPV) system.
Unlike panels, which are installed on top of the roof, BIPV systems are integrated directly into tiles, windows or facades. Consequently, they cannot generally be retrofitted on an existing structure and instead require a more substantial redevelopment of the building fabric.
Given the large, glazed roof area, it’s possible that the installation at the London Stadium will utilise photovoltaic glass. This may explain why the initial project cost estimates are around £4m, which is approximately four times higher than the cost of a conventional rooftop PV array of a similar size.
Are renewables on the right track?
While London mayor Sadiq Khan is making the right noises when it comes to the deployment of renewables in the capital, meeting the 1.5 GW 2030 target put forward as his preferred pathway will take around a six-fold increase from today’s level. To put that into context, that would be approximately twice the rate of growth required for the UK as a whole.
Flagship projects such as the London Stadium’s solar membrane are a step in the right direction but if we are to have any of chance of hitting the mayor’s ambitious targets, we also need to dramatically boost the deployment of solar across large commercial roof spaces.
Utilising the UK’s unused warehouse roofs could support the deployment of 15 GW of solar, which would contribute to almost a third of the UK’s 2030 target. This could generate additional revenue for landlords, providing cost savings to tenants at a time of historically high electricity prices, and giving the economy a much-needed boost.
Currently, big institutional investors have the resources and the investor pressure driving them to act. SMEs often have neither, and they’re missing out as a result. More knowledge among landlords and tenants around some of the fundamental questions underpinning rooftop solar, including contract templates, advice around how rooftop PV effects building insurance, roof warrantees, and repair liabilities is crucial.
Sadiq Khan and the GLA have set bold targets, but in the absence of a clear policy at national level, asset managers should be proactive in realising the opportunities that exist.
Anthony Maguire
Director
Longevity Power
Tel: +44 (0)20 3693 9814
admin@longevity-power.com
www.longevity-power.com
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