We are delighted to share that, during the BEAMA Annual Conference on November 27th, our collaboration with Tesla was Highly Commended in the BEAMA Net Zero Collaboration Award.
This acknowledges outstanding collaboration between companies that successfully contribute to advancing Net Zero, sustainability, and circularity within our industry or the broader market. It also recognises Wilson Power Solutions’ collaboration with Tesla, which represents a powerful synergy between energy innovation and network infrastructure manufacturers within the Battery Energy Storage System (BESS) market.

Contribution To Landmark Projects
Our collaboration with Tesla started in 2020 and is still ongoing. We focused on designing and redesigning transformers to utilise raw material and site footprint using modularity to maximise the storage capacity available to the network. We supplied Tesla landmark projects with over 330 transformers, including:
The largest BESS in Belgium, Eneco Wallonia 50MW/200MWh
The four largest BESS in the UK
Lakeside 100MW/200 MWh
Bumpers 99MW/198MWh
Clay Tye 99MW/198MWh
Pillswood 98MW/196MWh

The total battery energy storage installed and connected through our Large Distribution Transformers and Tesla batteries collaboration is now more than 1.6GWh. This suggests that with the integration of more renewables, these sites enhance grid reliability and are essentially the basis of infrastructure flexibility.
Drive Product Improvement
As the collaboration progressed over the years, both companies started to tailor designs and optimise the efficiency and productivity of the overall system. Tesla has focused on increasing their Megapack capacity without increasing its footprint. Wilson Power Solutions has optimised transformer sizes and design to connect as many as four Megapacks to one transformer.
The first projects used Wilson T2 Ecotrans Distribution Transformers with a 2.8MVA 33kV/480V rating and were filled with ONAN mineral oil. They also had single LV connections. Over the course of time and developing projects, Tesla Megapacks have now achieved greater capacity, and Wilson Power Solutions transformer has simultaneously evolved its designs to accommodate energy from these larger Megapacks. This has evolved through several iterations to optimise the transformer design based on project-level considerations, such as integrated bunds, KNAN insulating fluid, optimised LV and MV cable box design, and various other improvements.
Such design optimisation techniques have reduced the usage of raw materials, offered modularity and increased the output of the BESS sites, which is essential to both ROI & the available capacity to the grid. The new transformers are provided with a rating of 4.2MVA & 4.4MVA 33kV/480-480V allowing dual LV connections. This is one of the main improvements to include dual low-voltage windings to improve the resilience of the site without needing to install two separate transformers.
The continuous technological innovation has led to the following benefits, outlined in detail in the table below:
Energy savings from lower energy losses when comparing one 4.2MVA transformer to two 2.8MVA transformers
Reduced carbon footprint in raw materials resulting in reduced carbon emissions from transport, less use of cables and reduced foundation base.
The use of the KNAN fluid FR3 vegetable oil instead of mineral oil is biodegradable, reduces emissions and allows closer proximity of the Megapacks due to the higher flash/ignition point therefore less land is needed for the project.
Support for a circular economy – transformers can operate for decades and the materials used in the transformers are 90%+ recyclable (with biodegradable oil and fully reparable).
Cost-effectiveness by using less material and increasing the sites’ storage capacity.