As published in Bisnow on 23 April 2025.
The shape of the roof, the potential energy generated, the cost, surrounding buildings — there is a lot for a commercial property owner to consider when deciding whether to install a photovoltaic system.
However, modelling technology can radically speed up this assessment, said Simone Pagani, board director and chief services officer at GIA, which provides daylight, sunlight, rights of light, wind, building surveying and related technology services. By analysing a digital model of the roof using a whole wealth of data, developers and landlords can make far more informed decisions.
“We can scenario model any eventuality, taking into account factors from the physical space to energy volatility and the potential to generate income by monetising excess power,” he said. “We can look at one property or a whole portfolio. Overall, today it is possible to accurately understand PV as part of a wider decarbonisation and monetisation strategy.”
The potential for installing PV systems on the roofs and spare land of the UK’s commercial buildings is significant. Looking at industrial properties alone, the UK has 350M SM of warehouse roof space available in theory to use in power production.
No matter the asset class, installing solar brings a real benefit from a decarbonisation and energy performance certificate-rating perspective, said Justin McHenry, environment, social and governance and PV consultant at GIA.
“The other perspective is finance,” he said. “We have a client looking to demonstrate what they are doing about ESG, particularly the E, in order to access better rates when borrowing. Installation costs can also be used to reduce profits, so there is a tax incentive.”
Data centres in particular could benefit from installing solar, though placement is often complicated due to chillers being located on the roof. The UK government is hoping to accelerate the growth of AI, which is predicted to lead to a sixfold increase in the amount of power data centres use across the country.
Despite the benefits of solar, there are still barriers to adoption that are holding the industry back from realising the full potential of solar, McHenry said. The first hurdle is the limitations of the national grid.
“At the moment, the UK’s infrastructure isn’t able to easily absorb excess energy produced by private renewable sources,” he said. “While the goal is for self-consumption of the energy produced, they may produce more than they need at peak times. This limits the return on investment potential for a developer.”
Other barriers to adoption include the cost of installation versus the length of time it takes to see a return on investment, as well as questions surrounding who would maintain the system: the landlord or the tenant.
To help property owners overcome these barriers, GIA has developed an advanced desktop prediction tool that reduces the need for site visits, particularly at scoping stage. By creating precise digital models of roofscapes and analysing surrounding data, the team gives a much more accurate assessment of likely ROI and the potential energy generated, Pagani said.
To start, GIA creates a digital twin of the assets. Because many commercial buildings are in urban areas with complex surrounding roof structures, it’s not always straightforward where solar can be installed.
“We Our modeling is accurate to 15cm, which means we’re able to spot things that wouold be an impediment to solar, which other assessments might miss, such as where a nearby chimbey stack or lift overrun causes a shadow,” he said. “We can see the net usable area a roof has, which makes a huge difference to the quality of assessment.”
The team then overlays this model with information such as how much energy the building requires to operate, the cost of installing a system and even future developments nearby that could increase overshadowing. It includes an assessment of battery storage capacity and how this could help with self-consumption, such as storing cheap energy to use at peak times.
In the future, GIA could include urban wind energy in the solution as well as solar, a renewable source that Pagani said is currently being looked at in pilot government research.
One of the biggest benefits to GIA’s system is that it can be used portfolio wide, Pagani said. The solution can assess multiple assets, bringing data into one place to create a masterplan of PV potential.
“From here, you can filter out assets where it’s not worth installing a system because the payback is too small,” he said. “This is particularly useful for local authorities, which have hundreds of assets and are under pressure to decarbonise.”
GIA’s solution was born out of work with the Department for the Economy in Northern Ireland and Belfast City Council. The team used its expertise in 3D modeling, daylight analysis, energy forecasting and financial modelling to assess the potential for solar across Belfast.
GIA is now looking at incorporating data about the type of asset, such as how much energy educational institutions could produce, for instance.
“Delivering this information to government bodies would allow them to decide which areas to prioritise in terms of incentives, as they can see the real payback,” McHenry said. “Because the solution is scalable, we can really see the impact an incentive could have on a geographical area.”
Already, GIA is in conversation with a number of local authorities and commercial property developers about applications. Recently, the team mapped out the potential of having the biggest city solar farm on top of St Pancras station in London.
“Wouldn’t that be fantastic: to have solar installed on such a huge area with little overshadowing, just metres above the railway which is a huge consumer of energy,” Pagani said. “From a technical point of view, this would be an immediate contribution to the city’s decarbonisation.”