The Cowley solar PV project in the UK continues to progress as a major renewable energy development led by Sonnedix. Located in County Durham, the large-scale installation reflects ongoing investment in utility-scale solar infrastructure. Construction now at an advanced stage and commissioning expected in line with earlier timelines. The project maintains strategic importance within the UK’s clean energy transition. Moreover, it reinforces the role of solar PV in national generation capacity.
Progress and Current Status
Construction of the Cowley solar PV project began in April 2024, with site works advancing steadily across the development area. The 120 MW installation is now in its late construction phase, with grid connection and commissioning activities ongoing. Once operational, the facility will supply approximately 124,600 MWh of electricity annually, supporting around 35,000 homes while reducing carbon emissions significantly.
Moreover, the project benefits from the UK’s Contracts for Difference (CfD) scheme, which provides long-term revenue stability and strengthens investor confidence. As a result, the Cowley complex stands as a model for scalable solar deployment under structured policy support.
Across Europe, large-scale solar projects continue to redefine capacity benchmarks and grid integration strategies. Similarly, developments such as the Poland solar farm project led by Goldbeck Solar highlight the increasing scale of photovoltaic infrastructure across the continent. While the UK project focuses on national grid contribution, the Poland development demonstrates cross-border momentum toward high-capacity renewable systems, reinforcing Europe’s broader decarbonization agenda.
Construction Timeline
Construction is expected to be complete in 2025. Once operational, it will supply roughly 124 600 MWh of renewable electricity per year. This is enough to power 35 000 UK homes and avoid almost 48 000 metric tons of carbon dioxide emissions. Sonnedix supporting the country to meet its net zero goals through provision of clean and affordable energy in the UK. In addition, the company is also deploying green jobs. The Cowley plant is being built by EPC contractor Ameresco Sunel Energy Ltd, contributing to the local economy by providing over 100 green jobs in the area.
While the project cost has not been disclosed, the project will be funded through Sonnedix’ recent €500 million loan facility. The company secured this loan in December last year from six commercial lenders acting as mandated lead arrangers and hedging banks. These included BBVA, CIBC, NatWest, Rabobank, Banco Sabadell, and Santander Corporate & Investment Banking (Santander CIB), which also acted as agent for the facilities. On the transaction, Sonnedix was advised by Watson Farley Williams (legal and tax).
“With construction of the largest plant in our UK portfolio underway, we have marked a major milestone in our UK growth strategy. We are excited to be progressing our presence in the market and becoming a key player in helping the UK transition towards a clean, secure and sustainable energy system and meeting its decarbonisation goals,” said Axel Thiemann, CEO of Sonnedix.
The whole Cowley Complex plant is 100% contracted under the Government’s Contracts for Difference (CfD) scheme. This scheme aims to provide long-term price and revenue security. Following completion of construction of Cowley Complex, the CfD scheme will become effective in 2026.
The Cowley Complex solar Project Team
EPC contractor, Ameresco Sune Energy LTD, will build the Cowley plant. They will contribute to the local economy by providing over 100 green jobs in the area. Sonnedix currently has a total capacity of over 10GW. This includes a development pipeline of more than 6GW, across Chile, France, Germany, Italy, Japan, Poland, Portugal, Spain, USA, and UK. The company continues to expand its global footprint across OECD countries, through acquisitions and development of renewable energy projects.
“We’re extremely excited to be breaking ground on the Cowley Complex solar site. At 120MW, this is an important infrastructure project for the local area and providing over 100 green jobs during construction. Additionally, supplying secure green, affordable energy once operational. We’re very proud to be working on what is set to be one of the largest solar PV plants across the whole of the UK once completed,” said Jorge Amiano Goyarrola, Global Head of Engineering and Construction.
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RWE breaking into the UK solar market
In March this year, RWE begun construction on seven solar PV projects in the UK. They represent 330 MW of new, clean electricity capacity and are the company’s first solar plants in the country. RWE acquired JBM Solar, one of the UK’s largest independent solar and co-located battery developers, prior to construction of these projects. The acquisition included around 3.8 gigawatts (GW) capacity of solar and 2.3 GW of battery development projects. This positioned RWE as one of the UK’s largest solar developers. Furthermore, it was a clear demonstration of the company’s commitment to its continued investment in UK clean energies.
Scope of the Largest solar PV plant in the UK
The first of the seven sites is due to become fully operational by the end of 2024. The remainder will follow shortly after. Once fully operational, the sites will be capable of meeting the average annual electricity needs of over 140,000 typical UK homes. Additionally, reducing UK carbon emissions by an estimated 8 million tonnes during their lifetime. RWE will work closely with local parishes. Their projects will also contribute a total of £645,000 in community benefits to the neighbouring area directly supporting local projects. This is in addition to supporting local jobs and opportunities for local businesses.
In line with Britain’s ambitions for 70GW of solar capacity by 2035, RWE aims to commission on average 450MW of new UK solar capacity per year up to 2030. Globally, RWE plans to increase its installed solar capacity from 3.9 GW to 16 GW by 2030.
RWE has awarded major construction contracts to two UK-based contractors. These include Ethical Power and also Equans UK & Ireland, under its new brand Equans Solar & Storage. They will provide a comprehensive range of Engineering, Procurement and Construction (EPC) services to seven of RWE’s solar farm projects located across England, from north Devon to Lincolnshire.
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Overview of the Project: Cowley Solar PV Project (UK)
Project Name: Cowley Solar PV Complex
Developer / Owner: Sonnedix
Location: County Durham, United Kingdom
Capacity: 120 MW
Estimated Annual Output: ~124,600 MWh
Households Powered: ~35,000 homes
CO₂ Emissions Reduction: ~48,000 tonnes annually
Construction Start: April 2024
Current Status (2026): Advanced construction / near completion
Expected Operation: 2026 (under CfD framework)
Support Scheme: UK Contracts for Difference (CfD)
Project Type: Utility-scale solar photovoltaic (PV)
Project Team: Cowley Solar PV Project (UK)
Owner / Developer: Sonnedix
EPC Contractor: (Appointed contractors under Sonnedix delivery structure)
Construction Partners: UK-based civil and electrical contractors (multi-package delivery)
Grid Connection Partner: National Grid Electricity System Operator (ESO)
Technology Providers: Solar PV module and inverter suppliers (to Sonnedix specifications)
Financial Framework: Backed under UK CfD scheme with institutional investor support
Project Management: Sonnedix in-house development and delivery team
Regulatory Authorities: UK planning authorities and energy regulators
Operations & Maintenance: Sonnedix asset management division (post-completion)