Power You Can Trust



As the UK enters an unprecedented energy crisis, there has been extensive coverage in the press over recent months about the potential impact of limited gas supplies during the winter. This has been reaffirmed by the National Grid’s annual risk assessment which highlighted the relatively high level of risk for black outs to business and residential areas. This article by WB Power Services’ Geoff Halliday, focuses on some grid capacity limitations and how standby power should form an integral part of building design and management.


The UK, like many other European nations, has a high level of dependence on the use of gas for industrial, commercial, and domestic use, as well as for generation of electrical power. It is the dependence on gas for the generation of electricity needs, particularly at peak times, which sets the UK apart from several its European counterparts.

With over 70% of gas sourced from within the UK and Norway, the UK is better placed than many countries to deal with the supply strain this winter. However, our vulnerability will come from various sources of imported gas throughout winter, with the actual mix of supplies on any given day determined by the market. Whilst demand is expected to fall because of higher energy costs, we expect to see an increased use of gas for power generation; this will come in response to low imports /higher exports of electricity to France & the rest of Europe. Peak demand is predicted to be weekdays between 16:00 and 20:00 hours and during any cold snaps in December, January, and February. Of course, outages are also possible on other occasions too, more so if there is a persistent period of cold, frosty weather. With this heightened risk of power outages, businesses and homeowners dependant on keeping critical infrastructure up and running should be planning now for such eventualities.


Each business will have its own “critical infrastructure” to manage, be it a call centre, a small office with a shared server network and modem connection, a large manufacturing facility with process control system or robotics, hospital or blue light services, water pumping, and treatment centres, amongst others. Infrastructure of this type is typically protected either by an Uninterruptible Power Supply (UPS), standby diesel generating set(s) or ideally, both.

A UPS system is typically designed to regulate mains voltage and frequency, to cover short mains outages (brown outs), and to bridge the gap between the loss of mains power and a diesel generator starting and coming online, or for the system to safely power down. The support time provided will depend on the size of battery purchased and the UPS load at the time of the outage. We would expect to see a typical support time of between 5 and 15 minutes at full load.

The inclusion of a standby diesel generator within the infrastructure of a building adds significantly to its resilience against prolonged loss of grid power. It’s important to understand exactly what equipment within the building is connected to the generating set. For instance, is it just IT equipment and critical cooling? Or in the case of a call centre for example, does it also cover general lighting, communications equipment and work stations? If the generator covers just some desks but not all, then it is key to focus essential aspects of the business into those areas. It is also important to understand what part of the operation is not covered by the UPS as there will be a break in power of a few seconds whilst the generator is starting, plus a short break when the mains power returns.

In the case of a diesel generator, tank storage levels and running time will vary significantly. It is important to be aware of this, so that the likely maximum running time can be understood, and provision made for keeping the tank topped up, with knowledge of where additional fuel can be accessed at short notice.

If for example critical IT infrastructure is managed off site by a third-party provider, be it a large or small data centre operator, it is well worth checking that they have also made appropriate preparations.


Undertaking regular maintenance and testing of the backup infrastructure is the only way to ensure that when business needs backup power, it works. Undertaking regular preventative maintenance on MV / LV switchgear, UPS and diesel generating set(s) is not optional, but essential.

Most manufacturers will recommend two preventative visits per annum, with regular interim testing scheduled (in the case of a standby diesel generating set this is monthly). It is important that these tests should cover a whole building or key equipment mains failure. By having an all-encompassing check, it is the only way that facilities/estates teams can be sure that everything works as it should and provide confidence to those using the facility. It is also important that those operating the infrastructure are familiar with these processes too. Maintenance should ideally be undertaken by the manufacturer or an approved dealer; this ensures those undertaking the maintenance are thoroughly trained and have rapid access to spare parts should they be needed.

Preventive maintenance visits can identify the requirement for remedial works to take place, such as the replacement of starting batteries or UPS batteries, UPS cooling fans, generator belts and hoses. It is essential that these remedial works are completed immediately as otherwise they can impair reliability and performance.

If your business has not yet installed a generator or added a UPS to your infrastructure, speak with a member of the WBPS Sales team. We will be able to advise the best way forward to protect your business from the risk of short or long term power failures.