CASE STUDY: A challenging basement substation for M&S and ALDI

A former Morrisons supermarket on the Streatham High Street was being redeveloped into three commercial units. An upgraded electrical supply was needed with limited space for a substation.


The client initially approached UKPN who stated that the designated space did not meet their regulations and that the upgraded supply could not proceed.

Rock Power Connections suggested a standalone RMU and privately-owned transformer.

Guy Wyne, Site Manager said “Rock shoehorned a sub station in a very challenging space and kept us informed along the way and took care of everything for us

Colin Green, Rock's Project Manager, commented

We had a very accommodating client that worked with us extremely well, so we were able to deliver on time successfully and to the highest quality all round".


  • From the outset, the Project Manager Colin visited site and liaised between the client and UKPN to find an adjusted design that was fully compliant and practical for the client.

  • The Rock Team installed an 800kVA transformer and a standalone RMU both internally housed.

  • This was a particularly difficult install due to the location next to the tube station, the site restrictions and practical engineering on the site.


Rock Power Connections are on the customer’s side. With our experience and engineering knowledge, we successfully manage various ICP projects of varying size and scale across the UK. Our reputation for being a trusted an electrical connection partner is known across our industry and its why we work with so many returning customers.

By trusting Rock Power Connections with your new or upgraded electrical connection, you can rely on us to deliver your engineering solution on time and on budget. All our customers work closely with their dedicated Rock Power Connections Project Manager to develop a programme of works that fits with their engineering requirements and is flexible to their needs.

We’d be delighted to offer you a free, no obligation, competitive quote for your electrical connection project. Please email Emma on or call 01905 456384.

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