Are BESS systems a ‘green alternative’ to diesel?

The UK’s Department for Business, Energy & Industrial Strategy (BEIS) has developed an Electricity Supply Emergency Code (ESEC) which outlines the actions to be taken, and the timeframes, for electrical power stability recovery during an electrical power crisis. In the event of a substantial emergency, ESEC enables equal distribution of electricity supply to customers as far as reasonably practicable, while ensuring that pre-designated ‘protected sites’ maintain supplies for as long as possible.1 While the assumption is that the majority of healthcare sites would be considered ‘protected’, official recognition from their respective Distribution Network Operators (DNO) would confirm this.

Power restoration

The assumptions above are set out in more detail within the Northern Powergrid (NPG) document, Understanding emergency power cuts. Frequently Asked Questions, which states that healthcare sites classified as ‘protected sites’ are those which are ‘major hospital facilities with accident and emergency departments’.2 NPG, in its letter dated December 2022 sent to its priority customers, clarifies that no power restoration priority over other electrical power consumers is guaranteed to be provided by the service-provider, regardless of the healthcare site’s priority class. As regards power restoration to hospitals in general, the initial ‘FAQ document’ states that ‘Most hospitals have back-up generators to ensure that they can continue to operate in the event of power disruption’. A recommendation is made to review any potential risks to the site, and to have strategies in place should power cuts last longer than three hours.