Photovoltaic panels and battery storage provide commercially viable energy for the county.
- Project: West Sussex CC energy programme
- Objectives: Deliver the council energy strategy
- Timescale: 2013 to present
- Cost to authority: Roughly £23m to date
- Staff working on project: Five
- Outcomes: Projects that generate secure, affordable and environmentally sustainable energy for the county. Tangmere brought in £636,000 in net income in the past year, and Westhampnett is expected to bring in £230,000 in net income per year on average throughout its life.
- Officer contact details: Siobhan Walker
When we switched on Westhampnett solar farm – the UK’s first publicly owned, subsidy free solar farm – at the end of 2018, some were surprised that a small public sector body was making bold strides into the renewable energy sector ahead of more established developers.
The farm joins the council’s growing portfolio of solar generation assets with a combined 20MW generation capacity, including two solar farms and solar panels installed on our buildings and schools. West Sussex CC is gradually delivering its long-term energy strategy and developing new ways of generating environmentally sustainable, secure and affordable local energy.
The council already runs its own not-for-profit local energy supplier, providing competitively priced gas and renewable electricity for residents. It has just under 4,000 customers, achieved through low and no-cost marketing. Customer growth remains steady.
It is also leading Businesspark Integrated Sustainable Energy Packages, a long-term, EU-funded project to help businesses on one of the south east’s biggest business districts to generate, share and use more renewable energy and heat.
Westhampnett is our second solar farm after the 5MW Tangmere site opened in 2015. The 26,000 solar panels at Westhampnett generate enough green energy to power 2,400 homes and provide vital income from a council-owned site unsuitable for other development due to the presence of methane gas from the landfill site which closed in the 1990s. The council uses some of the energy generated from its solar farms to power its own buildings and reduce exposure to energy price volatility.
In terms of scale and challenge, Westhampnett was a step change in West Sussex’s renewable energy ambitions. Feed-in tariffs which helped the council develop Tangmere solar farm were being withdrawn for new projects, prompting it to come up with a new financial model to make future large solar generation projects stack up and pass the council’s strict internal criteria governing financial rate of return and project payback.
Early on, West Sussex explored and ruled out the prospect of a ‘private wire’ arrangement. Under this, electricity generated at Westhampnett would have been supplied directly through a commercial agreement to a large local electricity consumer, without being fed into the local electricity grid.
Feasibility work to explore potential energy storage led to installing large, containerised, grid-scale batteries alongside the solar farm as the most reliable way to maximise the site’s generation capacity and deliver the financial returns needed to compensate the loss of the feed-in tariff.
The 4MW battery capacity at Westhampnett allows the council to absorb the surplus electricity generated during the day, store it and release it to the grid when the demand peaks and the value of the electricity is highest.
Given the growing amount of renewable energy generation from wind and solar nationally, large energy storage of this kind is becoming increasingly important to smoothing out the inherent peaks and troughs in generation across the grid. The batteries are part of the solution.
The authority earns income for providing these ‘grid services’ and helping to balance supply and demand. With the batteries commissioned and fully operational since the end of 2018, West Sussex has already taken advantage of a number of ‘triad’ periods when electricity is in particularly high demand on the local electricity grid.
Although the council expects to develop further solar farms in the medium term, the immediate focus is on developing a number of standalone battery sites. These will be similar to the battery installation at Westhampnett and make use of pockets of land the council already owns.
These new battery sites will be larger than Westhampnett and draw electricity from the grid rather than a nearby solar farm. But the principle will be the same. Electricity will be released to the grid when it is in demand, earning the council income.
Feasibility work is being carried out at three sites. A planning application and successful grid application has been submitted for one of them. If planning consent is granted, a derelict former waste site at Sompting, near Worthing, will become home to more than 40MW of clean and quiet lithium-ion batteries that will provide grid services from summer 2020.
Alongside our large battery and solar programme, we are also exploring how smaller battery installations can be installed at council buildings and schools. We are carrying out a pilot across several sites this year and will develop business cases for the most viable ones.
We are particularly interested in batteries as a complement to the council’s schools solar photovoltaic programme which will have delivered more than 70 installations, some as large as 200kW, by the end of this financial year.
As we work to complete all the school installations before the government withdraws the feed-in tariff at the end of the financial year, we are looking to battery storage as a way of maximising the potential of these systems and, potentially, helping more schools to reduce their energy bills by extending the solar PV programme beyond April 2019.
Siobhan Walker, project manager, West Sussex CC