Case Studies:




ESM CONNECT - Coltishall

Scottow Moor Solar Ltd is a company that was specifically created to develop the solar farms including this one near Norwich. They have extensive experience in renewable energy projects in the UK and overseas.

The site

Using the former RAF base of Coltishall, Norfolk County Council's vision was to use the land to its full potential, generating income, creating jobs and protecting the site's heritage assets. After deciding that a solar farm was the best use of the land, applications were approved and the first phase started in February 2015.

Our work

ESM Power Ltd were chosen as one of the main contractors to help realise the potential of generating enough clean energy to power around 12,000 homes and saving 20,000 tonnes of CO2 each year. Our first phase was completed within a very tight deadline and included:

• Designing and installing both the DNO and customer 33kV substations and switchboards

• Civil and electrical designs

• Procurement, installation and commissioning of all equipment

• Connecting 27MW of solar generation to the grid network

Phase two

After the successful first phase, we began phase two which included all of the ICP work and a 33kV DNO connection. We also added a further 20MW to the grid connection as well as four new circuit breakers and two switches. The four customer substations had three 500kVA transformers and another 200kVA transformer added.

ESM Power worked with several contractors as well as using our own resources to complete the work and saw us responsible for the LV changeover as well as all commissioning, cable installations, terminations, and excavations.

The site also presented challenges we had to overcome, including contamination from asbestos and obstructions underground from existing services.

We were delighted to work on this major clean energy project. The scheme involved an imaginative design solution to enable the connection of five separate 5MVA solar parks to the same point.



Ruskin Square is a large mixed development, located in the heart of Croydon's central business district. The project includes residential units, shops, cafes, restaurants and appealing public spaces. There will also be fast and easy access to central London as well as excellent public transport connections.

The work

We are contracted with the developer, Stanhope Plc who have over 30 years of experience and an impressive track record. Stanhope Plc chose ESM Power Ltd to provide a connection of 16.4 MVA, 11kV supply to Ruskin Square.

Work began in 2013 and will continue over the next 10 years as the site is developed in stages to include four residential buildings which are all low voltage (LV) metered and five commercial buildings which are all high voltage (HV) metered.

To date, ESM Power has provided the following:

•  A temporary building supply connection for residential number 1 development

•  Three 11kV circuits to the main site from UKPN Croydon Central Substation

•  11kV supply to the first residential development

•  A temporary building supply to building number 3

•  11kV supply to the second residential development and box park

For the initial phase of the development, we provided a temporary building supply by installing a UKPN approved ring main unit and a private customer transformer which was energised in March 2014.

The permanent supply to residential number 1 involved the connection of three 11kV feeders to the site into a UKPN approved trunk feeder unit.

A UKPN approved unit substation was also installed, consisting of a Schneider 1000kVA unit transformer utilised to provide the LV cut outs to the residential building.

Main supply and tram crossings

The point of connection for the main supply was an existing UKPN substation at Croydon Central. To provide the 16.4MVA capacity, three underground 11kV circuits were required. This involved trenching through highway, footpaths, and three tram crossings through central Croydon, using a technique called 'pipe jacking'.

For one tram crossing, we had to close an existing subway station and construct a steel piped box section through the subway.

The project has involved us working with main contractors and a wide range of professional teams including MEP consultants, architects and cost consultants. We are excited to continue with this major development and look forward to seeing Ruskin Square's vibrant new image.


ESM CONNECT - West Raynham

The site

The 225-acre site at West Raynham is a former RAF station and was chosen due to its reputation as being one of the sunniest places in the UK. The farm aims to power more than 14,000 homes for the next 25 years and ESM Power was chosen as the principal contractor, beginning the first phase of connection in September 2014.

Our work

In a six-month period from September 2014 to March 2015 we completed both the physical build of the 132kV/33kV substation and the 9km 33kV cable route to the solar farm.

ESM Power designed, procured, installed and commissioned the high voltage infrastructure to the solar farm. We managed the 132kV point of connection (POC) interface on behalf of the client with UK Power Networks. As the ICP, we also undertook the contestable element of the 132kV works to UKPN standards.

The site features around 200,000 solar panels producing 49.9MW.


ESM CONNECT - Stainforth

The site

151 plot housing development on Briars Lane in Stainforth, Doncaster. Work commenced in July 2017 and will be an ongoing project.

The Client

Owner and developer, RoadGaz Group will be constructing new build properties in Stainforth, Doncaster and have awarded GS Energy Connections the job to complete the electrical, water and gas connections to the properties. As specialists in water and gas, GS Energy Connections have assigned ESM Power the electrical part of the project due to our expansive knowledge in the area.

Our Works

ESM Power's work on the project consists of installing a new substation to supply the site with the required load for the properties. The substation will be connected to the local network by high voltage cables and these will then go on to be adopted by the local distribution network operator, Northern Power Grid.

Within the brick built substation enclosure we installed a 315kVA package substation which included a ring main unit, 315kVA transformer that will step down the voltage from 11,000V to 433V and a low voltage cabinet which allows the low voltage cables to run out through the site. These will then be separated further to allow each property to be connected individually with its own electrical supply - the same applies for the water and gas.

We will be staging design and construction throughout the phasing of this ongoing project. The first phase consisted of 43 plots, including 4 initial show homes, which the developer requested to be connected first in order for potential buyers to see how each property was laid out. ESM Power will continue to work with the client to deliver connections to different properties including flats and houses.


Troughton Solar Farm

The site

Covering around 100 acres, this flat site powers over 7,500 homes and saves 10,750 tonnes of CO2 emissions every year.

Our work

ESM Power Ltd was chosen for the design, procurement and construction of a new 132kV sub-station to accommodate the 25MW export to the point of connection on Western Power Distribution (WPD) network. Design commenced in February 2015 with construction starting in August 2015 and completed in March 2016. The wet weather in late winter was a particular challenge but we overcame all obstacles to get the project completed on time. Among a range of works, we carried out the following design, build, commission and handover to the DNO:

•   A detailed civil and electrical design to WPD's specifications for the 132kV metered substation and private substation

•   Earth resistivity testing and earthing design

•   Supply and construction of the support structure for the surge arresters and three disconnectors 

•   Supply and installation of a 132kV metered circuit breaker, a 132kV to 33kV 25/30 MVA distribution transformer complete with a 33kV three-panel switchboard 

•   Supply and installation of a 50/100kVA auxiliary transformer 

•   Directional drill under the M5 motorway as part of the cable route 

•   Full commissioning including G59

This connection is ESM Power's second 132kV site and has added 25MW of solar connection to our portfolio.


For more information on any of our services, quotations or general enquiries, contact ESM Power.