The race to net zero is gathering pace across the UK transport sector. Infrastructure owners are under increasing pressure to decarbonise their operations. For one major UK train depot, this challenge became an opportunity to demonstrate leadership in both sustainability and community engagement.
Working with our community energy partner, Carbon3 delivered a significant rooftop solar PV project designed to reduce emissions, and generate long-term community benefit. The project represents a milestone in solar deployment within the rail sector and also highlights the power of community-led investment models in accelerating the clean energy transition.
The challenge
The depot had set ambitious targets around carbon reduction and operational sustainability. However, like many large industrial or transport sites, they faced significant funding issues. Despite a large roof space and high energy demand, the site lacked the funding to invest in a large-scale renewable energy system outright.
At the same time, rising electricity costs and pressure to decarbonise fleet maintenance and operations meant the depot needed a fast, cost-effective way to generate clean, on-site power, without compromising its day-to-day activities.
The solution
To overcome these barriers, the depot partnered with Carbon3 to deliver a 380kWp solar PV system. The installation comprised 950 high-efficiency solar panels, generating an estimated 328,764 kilowatt-hours of renewable electricity per year. This output will offset approximately 90.32 tonnes of carbon dioxide annually, which is the equivalent of taking dozens of cars off the road each year.
The system was fully funded through Energy Garden’s community share offer. This allowed local residents and ethical investors to purchase shares in the project. Investors earn a modest return on their investment, while further profits are reinvested in local education, environmental and youth programmes to create social value far beyond the depot walls.
Carbon3 handled the full design and delivery of the system, including grid coordination and a five-year operations and maintenance agreement. This ensures long-term performance and gives the depot peace of mind, knowing the system will be monitored and maintained by expert engineers for years to come.
A scalable model for commercial solar
The scale and complexity of the depot made this an ambitious project. But, it’s also a clear demonstration of what’s possible when technical delivery and innovative funding align. With 950 panels installed on existing roof infrastructure, this project represents one of the largest solar PV installations delivered under a community energy PPA within the transport sector.
Importantly, the system is directly connected to the depot’s power infrastructure, enabling it to consume the electricity on-site and reduce reliance on increasingly expensive grid energy. The depot now benefits from a long-term, stable supply of clean power without any upfront capital expenditure.
What is a community energy PPA?
Power Purchase Agreements (PPAs) are a tried-and-tested method of financing renewable energy. Under a traditional PPA, a third-party funder owns the solar installation and sells the electricity generated to the host site at a lower rate than the grid. This arrangement helps businesses avoid the upfront cost of installation, while still benefiting from clean energy and cost savings.
What makes the community energy approach different is the source of that funding. Instead of relying on private equity or institutional investors, these projects are financed through community share offers. Local residents, climate-conscious citizens, and ethical investors pool their money to fund solar projects to receive a return, while generating lasting benefit for local people.
In the case of the train depot, this meant the client could take advantage of clean energy, reduce emissions, and avoid capital cost while knowing the savings and profits were being directed back into the communities it serves.
The results
Since installation, the 380kWp system has delivered consistent performance, generating enough electricity to power the equivalent of around 90 homes annually. The carbon savings are substantial and immediate, with over 90 tonnes of CO₂ avoided each year.
Operationally, the depot has seen no disruption. The solar installation was delivered with careful planning around schedules and access, and now runs quietly and autonomously, supported by Carbon3’s remote monitoring systems.
The five-year O&M contract ensures all servicing, inspections, and reporting are handled professionally, with no burden on the depot’s facilities team.
Why it matters
This project offers a model that balances climate action with financial and social responsibility. It shows that commercial sites, even those with limited budgets, can install large-scale solar PV systems with no upfront cost. They can still benefit from long-term savings and decarbonisation.
Just as importantly, it demonstrates how sustainability strategies can go beyond compliance. By opting for a community-funded PPA, this depot became part of a bigger story. They are supporting education, employment and environmental justice in the communities where they operate.
A blueprint for future transport decarbonisation
This installation is now part of our community energy partner’s growing portfolio of community energy projects across London and the South East. As more transport and infrastructure operators look for ways to hit net zero targets without overextending capital budgets, community PPAs offer a proven solution.
Looking ahead
The depot project shows the benefits of commercial solar PV when paired with flexible funding models. As energy prices rise and pressure mounts to decarbonise, we expect to see more businesses and public bodies explore PPA options that are community-backed.
If you’re managing a commercial site and want to explore solar PV without capital cost, talk to Carbon3 today. We can help connect you with funding partners, deliver a tailored solar design, and manage the process from feasibility to final installation.
