Wilson t2 ecotrans distribution transformers at pillswood battery energy storage system (bess)

Projects
Pillswood BESS

98MW/196MWh Pillswood BESS

Pillswood Battery Energy Storage System (BESS) is a large-scale energy storage project located in Cottingham near Hull, East Yorkshire, UK. Developed by Harmony Energy in partnership with Tesla, it is one of Europe's largest battery storage facilities. It is key in supporting the UK's transition to renewable energy. The project became operational in November 2022, four months ahead of schedule, making it the largest BESS in Europe by megawatt hours.

Pillswood BESS has a total capacity of 98MW and can store up to 196MWh of electricity. This is enough energy to power around 300,000 homes for two hours during peak demand periods. The system utilises Tesla Megapack batteries, which are designed for grid-scale energy storage and offer high efficiency, rapid deployment, and advanced energy management capabilities. Tesla's Autobidder AI software is also used to optimise energy trading and grid balancing.

The facility is strategically located near National Grid’s Creyke Beck substation, which is a key connection point for the Dogger Bank Wind Farm, the world’s largest offshore wind farm. By storing excess electricity generated by offshore wind turbines and releasing it when demand is high, the Pillswood BESS helps to reduce reliance on fossil fuel-based power plants, enhance grid stability, and support the integration of renewable energy.

Wilson Power Solutions supplied the site with Forty 2800kVA 33kV/480V Wilson T2 Ecotrans® MV Transformers, which were specially painted to match the white Tesla Megapacks. Pillswood utilises 78 Tesla Megapacks connected to the grid using power and distribution transformers. These transformers ensure the voltage of the imported and exported energy matches the voltage level of the grid connection and batteries.

The National Grid Energy System Operator has asked wind farms to switch off in the past when there is a consumption/generation imbalance. Battery energy storage systems like Pillswood prove necessary for NG to maximise the utilisation of the energy generated by wind farms.

Sector	Battery Energy Storage System
Developer	Harmony Energy
Project	Pillswood 98MW/196MWh
Location	Cottingham, Hull
Scope of Work	Forty 2.8MVA 33kV/480V Wilson T2 Ecotrans® Distribution Transformers

Erika Wilson - Managing Director - Wilson Power Solutions

“We are delighted to work on this important green energy project with Tesla and Harmony Energy, a fellow Yorkshire company. There is an increasing demand for transformers to support the growth of renewable and BESS sites in the UK. We customise the transformers' design to cater to the technical requirements of each project. BESS sites such as Pillswood benefited from this, aspiring to find the right balance between improving reliability and addressing material efficiency.”

Erika Wilson - Managing Director

Wilson Power Solutions

Tesla Megapacks

196 MWh

of electricity

300000

homes powered

for two hours

Peter Kavanagh Harmony Energy credit Harmony Energy

“Battery energy storage systems are essential to unlocking the full potential of renewable energy in the UK, and we hope this particular one highlights Yorkshire as a leader in green energy solutions.

“I would like to thank Wilson Power Solutions, in Leeds, for their efforts, which for the first time saw them finishing the transformers in white to match the Tesla Megapacks.”

Peter Kavannah, CEO - Harmony Energy

Wilson T2 Ecotrans large distribution transformer at BESS Pillswood

T2 distribution transformers at BESS Pillswood