For years, the University of Manchester has been searching for a long-term supply of low-carbon energy.

To set the scene, Julian Skyrme, Executive Director of Social Responsibility, looked back into history at Medebridge’s official launch ceremony on 10 October. Manchester was the world’s first industrial city, powered through coal; the city still has some of the worst rates of asthma in the country. But in 2019, Manchester was the first UK city to set a science-based target toward zero emissions, with a net zero target of 2038, 12 years before the rest of the country.

Why invest in solar power, he asked rhetorically. His answer was that it’s a strategic commitment. The University of Manchester was the first university to place social responsibility as a core goal, an action dating from 2011. The University is top in Britain in achieving against UN Sustainable Development Goals. And among the metrics in the new Manchester 2035 strategy is zero carbon Scope 1 and 2 (direct and indirect) emissions by 2038. ‘This investment [in the Medebridge solar farm] increases our confidence of achieving that,’ Skyrme said.

In 2018, the University had a brown energy contract, with an input of perhaps 8–10% renewables, which was nothing to be proud of, recalled Finance & Administration Manager Lee Barlow. The first step towards greener energy procurement was switching to sourcing energy with Renewable Energy Guarantees of Origin (REGO) certificates, which it did in January 2020, only a few months before COVID hit. The University received Board approval to invest in solar in 2021, and then the Ukraine war and the energy crisis hit. Meanwhile, the number of suitable solar projects to provide the power shrank, from 18, to three, to two, and then it went to public-sector tender.

What resulted in the end was a 10-year corporate power purchase agreement (CPPA) for 80% of Medebridge’s power to meet 65% of the University’s electricity requirements. Managing the tender was just part of the scope of work carried out by energy consultancy Inspired, which also manages natural gas contracts for the University. The University spends £25mn/y on energy.

Hal Chapman-Daws, Account Manager at Inspired, said: ‘This is the culmination of years of meticulous contract negotiations and support our technical experts have provided. Integrating the CPPA into the University of Manchester’s wider strategy ensures lasting value, sustainable growth and benefits that extend across all services.’ 

He explained that the agreement involves three parties: the University of Manchester, solar farm developer Enviromena and electricity utility EDF, which is the offtaker at Medebridge and is the electricity supplier to the University that is located on the other side of the country from the solar farm. Although the CPPA covers most of the solar farm’s output, actual production varies depending on the weather and across seasons. For that reason, and to simplify the transactions, the electricity is traded in blocks.

Tom Abbott, PPA Director, EDF, said: ‘By bringing power from Medebridge solar farm through this tailored CPPA, we’re showing how smart partnerships can unlock big wins for decarbonisation. Our balancing, shaping and sleeving services mean the University gets dependable clean power – and a clear path towards its net zero goals.’

The site 
The origins of the solar farm can also be traced through the history of the site in South Ockenden, Essex. There’s the developer Enviromena, an independent power producer which came to the UK in 2018 after being founded in the Middle East a decade before. Now a subsidiary of Arjun Infrastructure Partners, Enviromena is headquartered in the UK but has a European scope. It is managing 170 MW of capacity in construction, including a project in South Wales, 400 MW in operation and 3 GW of projects in planning, including three other solar farm sites across the country that it bought this past summer.

In April 2024, Enviromena bought the Medebridge site from NTR, operator of the neighbouring 59 MWp Ockendon solar farm. The Ockendon solar farm is located on a repurposed landfill site and was originally developed by landfill operator Veolia and REG Power Management. Both sites were sold on to NTR in 2022.

Enviromena developed, built and now manages the Medebridge solar farm, which was energised in late summer. Despite going from empty field to power in 16 months, the developer had to overcome a number of site challenges. Although the site came with planning permission and a grid connection, one of the outstanding items to resolve was the Lower Thames Crossing, an eight-lane motorway planned to run in between the solar farm’s three fields. To avoid interfering with the laying of the motorway roadbed, the solar farm's power cables needed to be buried 2.7 metres below ground; digging to that depth required excavating a terraced, 60 metre-wide trench. Another complexity was the grid connection. Originally designed for a single input from a single operator, it was split between NTR and Enviromena, who share ownership of the 132 kV transformer at the substation 50:50. Despite its tiny scope of operations, this consortium is effectively an independent network operator, with all of the governance bureaucracy that comes with it, including board meetings.

Over 175 acres, Enviromena installed 102,508 Trina Solar bifacial panels mounted on 1,063 tonnes of supporting steel with 600,000 nuts and bolts. Each 690 Watt-capacity panel weighs 36 kg and required a team of eight to install. That process took just five weeks, although full construction of the solar farm took a year, mainly because of all of the wiring.

The panels, daisy-chained into groups of about 20, feed 102 field Huawei 300 KTL inverters that transform the electricity from 800 Volts DC to AC. They in turn feed 17 field transformers which raise the voltage to 33 kV AC. The principal purpose of the field transformers is to reduce the amount of site cabling. Other aspects of the installation are optimised to ease maintenance. Panel strings feeding inverters are labelled. The inverters are mounted at chest height for ease of access. Cables are protected with PVC ducting to protect them from the equipment used to trim the weeds. Pyrometers measure the amount of solar incidence. Nearby are thermometers measuring ambient air and panel temperatures; maximum panel temperature is 40°C.

SCADA systems pinpoint a lack of power to help engineers troubleshoot issues, in addition to fault code alarms at Enviromena’s control centre, which monitors the site in real time and provides information for day-ahead forecasting. Its heat maps are so precise that they can detect the drop in incidence from a cloud passing through the sky.

CEO Chris Marsh concludes: ‘The collaboration with the University of Manchester, EDF and Inspired has been exemplary and it shows what’s possible when ambitious organisations come together with a shared purpose. Medebridge represents the future of corporate sustainability.’

• Further reading: ‘European manufacturing cost premiums raise solar LCOE 15% above that of Chinese-made panels’. Producing a solar module in Europe with EU-made solar cells costs around 18% more than producing the same module in China, according to a new report from SolarPower Europe and the Fraunhofer Institute for Solar Energy Systems (ISE).
• By 2029 solar PV is on course to be the largest source of renewable generation worldwide. But that does not mean all solar panels are as effective in generating power as others. Claire Cortis, Digital Knowledge and Information Manager at the Energy Institute, compares solar capacity factors of the top 20 solar PV generating countries and looks at the technologies being developed that could improve them.