West Midlands Police – Central Custody Suite

About the client

West Midlands Police is the second largest police force in the country, covering an area of 348 square miles and serving a population of almost 2.8 million.

The force deals with more than 2,000 emergency calls for help every day, as well as patrolling the streets and responding to incidents 24-hours-a-day, seven days a week.

Drivers for the project

The Police Authority wanted to invest in technology to reduce their Carbon Emissions and help save on energy costs.


We secured this project via a competitive tendering process and worked as the main contractor under a JCT Contract for the Design, Installation, commissioning of a solar installation onto the roof of the Central Custody Suite 249.7kWp.


As part of the initial design phase our design engineering team reviewed the clients half hourly electrical data in order to size the solar system appropriately a number of options were presented to the client based on current and future electrical consumption usage on site. Electrical schematics were produced to include the current set-up on site, which included a CHP generator capable of stand-alone operation. 

Access to plant area and roof had to be carefully worked for these sites with 24/7 public access and operational activities. Roof access also included the addition of walkways to protect the roof surface and allow easier access for any future maintenance needs.

A 249.7kWp system was designed using 908 No. 275Wp panels and 5 No. 36kW Huawei inverters. Suitable isolators, a new dedicated PV distribution board and generation meter were installed and fitted seamlessly into the sites existing electrical network.

It will produce enough electricity (196,590 kWh per annum) to power around 53 residential homes per year or power 89 electric cars. After 25 years of operation the project is predicted to have saved 365.1 tonnes of CO2e, an equivalent of 1,889,452 fossil fuelled car miles, 239 fossil fuelled cars off the roads and 1460 pine trees planted.


The site was equipped with backup generation, so the inverters had to be connected to the non-essential side of the main site distribution board. The inverters themselves had to be installed on bespoke framing with DC cable running directly down from overhead. A lack of 3G signal meant a high gain antenna was required to be installed.

Given the nature of the building which is one of the largest custody suites in the midlands a formal vetting process of all Custom Solar staff was required to meet security standards along with a building access plan which was critical to allow access without interfering with public access to this 24hr operational site

Roof access also included the addition of walkways to protect the roof surface and allow easier access for any future maintenance needs.


The initial programme was to complete the installation within two weeks and we successfully delivered a fully commissioned system following a client handover within this period despite issues with weather conditions. We also have a contract to operate and maintain the system for which to date the system is performing 10% over the predicted yield.

Project details

System size
249.7 KWP
Panel Manufacturer
BYD 275
Number of panels
Inverter Manufacturer
Estimated System Annual Performance
196,590 KWH
365.1 TONNES
Completion date
March 2019
West Midlands Police – Central Custody Suite website