Digital Realty Data Centre


Digital Realty


Data centre, Chessington, UK

Customer Requirement

Standby power generation


Design, mechanical engineering, equipment supply, ancillary equipment, project management, installation, commissioning, maintenance, genuine parts supply

Power Need

Digital Realty required a back-up power installation at its new, flagship datacenter in Chessington, South West London.  


Having worked with Finning on previous projects, Digital Realty (DLR) again partnered with Finning to supply the back-up power. 

The site includes two 1,440 kW turnkey flex data halls, where Finning has supplied six Cat® 3512BHD generator sets in a pod arrangement. Each pod has three generators installed on an N+1 basis producing a combined power (N) of 3000 KWe. Each pod contains three 1875 kVA standby diesel generator sets with operator control panel, together with self-contained fuel system and remote cooling.   

Reducing noise pollution is particularly important, so Finning engineered the package with an air inlet and discharge system and exhaust gas silencers all sized to achieve levels no greater than 70 dBA within a one metre radius and with two generator sets running.   

DLR has made significant investment in the facility’s cooling infrastructure and so the Finning team ensured that all of the power equipment installed was optimised to reduce parasitic heat transfer; such as jacketing the heat exchanger located in the plant room to minimise heat losses. Each generator set also has its own remote cooler, heat exchanger and circulation pump.   

A purpose-built fuel system for each pod consists of a 25,000 litre day tank serving three, smaller 600 litre tanks acting as a dedicated fill point for each generator. The feed to each day tank is supported by a dedicated duty, standby fuel pump housed in the end enclosure of each above ground bulk tank.   


The new facility offers the latest advancements in efficient datacentre design, enabling very effective Power Utilisation Efficiency (PUE) and 99.999% uptime and above, as well as innovative cooling methods, including outside air free-cooling chillers operating at enhanced temperatures for greater part load and overall power efficiency.   

Mike Golding, European Construction Director at Digital Realty comments, “interest in our new Chessington facilityis high, with a third of the data space leased already. Ensuring that we provide the high efficiency levels required to meet this customer demand requires a highly dependable emergency power infrastructure. Having worked with Finning for more than two years and benefitted from the company’s robust Cat product, engineering expertise and its service capability, it was clear that we should work together on this project to achieve the secure power supply require”.