Sites evolve and grow in size and scale, often without the necessary electrical upgrades to match. And all too often, the on-site maintenance team is expected to maintain not only all mechanical and electrical elements within their site, such as process machinery, drives and conveyors for example, but in addition the electrical infrastructure network is now part of a maintenance team’s responsibility. Operational process equipment breakdowns take priority, which means that a seemingly functioning electrical network is neglected and often falls to the bottom of the list. Added to this, with so much focus on operational process uptime, many teams may not have access to the latest system knowledge or training to enable them to accurately diagnose an infrastructure issue, should it arise.
Failing to proactively update, inspect and service electrical infrastructure equipment could cost an organisation dearly, both financially and reputationally, so understanding the risks at play is vital. Here are four steps organisations can take to improve their energy resilience:
Understand your energy usage
Take a top-to-bottom approach to understand power usage across your operations, and to assess whether your electrical infrastructure is still fit for purpose. Your electrical power requirements may have changed since the infrastructure was first built. It’s important to understand how much of the power available is actually used and to identify any unused capacity or power losses. Consider substations and switchboards. How many circuit breakers are used and what is their load current? Are they working at or in excess of their rated levels due to operational expansion, or is there scope for network rationalisation due to a reduction in operations?
Running at or near the full load current limit accelerates the ageing of equipment. Overheating and full load operation leads to excessive wear and tear, so carry out a full network study of load current flow and evaluate ‘new’ fault levels. Include HV/MV switchgear, LV distribution switchboards, primary power cables, transformers as well as control and protection equipment. Also take into consideration any new loads that the electrical infrastructure now feeds and carry out a protection study to ensure its correct operation in the event of an electrical fault.
Evaluate your risks
Just how big is your risk from electrical faults? Calculate the impact of blackouts and brownouts on your business operations in terms of costs, delays, production losses, health and safety aspects and more. If you include contractual penalties from non-delivery and invalidated company insurance policies, downtime can quite literally cost tens or hundreds of thousands of pounds per day or hour. A risk profile map of the entire site provides an overview of key energy assets that could fail and can help highlight possible risks.
For example, a power failure affecting loading bays could lead to severe delays. Raw materials that can’t be unloaded and processed mean possible wastage and reduced production capacity, while delays in loading outbound goods might result in an inability to meet customer production and delivery targets.
Elsewhere, supply chain and production bottlenecks could lead to higher reliance on completed products stored in the warehouse, followed by an inability to correctly catalogue stock levels. If the outage affects the communication network, there is no visibility into incoming our outgoing goods, the factory environment and site security – and it could be necessary to evacuate non-essential personnel, delaying operations even further.
Identify the weak spots in your energy infrastructure
Once you have a good understanding of your energy risk, look at the equipment that forms part of your electrical infrastructure and identify any network single points of failure as well as potential issues that require servicing, upgrading, uprating or monitoring. What can be measured can be improved: Conduct a comprehensive audit using thermal image cameras and test asset insulation mediums checking for oil (DGA) and SF6 (Humidity/Dew Point/SO2 Sulphur Dioxide) quality. Include other diagnostic electrical tests such as switchgear operating times and primary contact resistance. Check for unusual smells, leaks, asset corrosion and debris; pay attention to busbar and cable connections, pipework and insulating materials; look for overheating or loose wires. Remember that small issues can lead to big risks and can be an early indication of potentially catastrophic faults.
With the right service, maintenance and refurbishment, switchgear can last up to 50 years, but leaks can cause flashover leading to injury, a breach of HSE regulations and damage to the environment with oil entering any localised drainage or a potent greenhouse gas being released in the case of SF6. This is why it is vital to detect any issues early.
Don’t overlook the smaller electrical infrastructure subcomponents either. If not inspected, serviced updated or replaced often enough, they can have a big impact on the reliability and resilience of your power supply. These can include MV/LV circuit breaker sub-assemblies, MV/LV switchgear cubicles, battery/UPS systems, high-voltage bushings, insulators, and protection relays.
If possible, a full energy infrastructure audit should be conducted either by the original equipment manufacturer (OEM) or by an organisation able to independently assess the performance of your assets.
Have a long-term risk mitigation strategy
Any infrastructure issues identified by the audit will need prioritising and rectifying. Again, the OEM should be your first port of call as they have quicker access to technical experts and replacement parts and know how to optimise equipment performance. In addition, they may be able to offer a more tailored remediation solution.
Ripping out and replacing isn’t always necessary and should be a last resort. Often, equipment can be serviced on site instead, taken for a factory repair or be refurbished with new parts. Retrofitting or upgrading legacy equipment with new technology to extend its lifecycle can also be an option provided by the OEM. A skilled OEM will offer this flexibility of approach to limit downtime and costs to site.
Once immediate issues have been addressed, implement a long-term energy resilience strategy to mitigate future risks to your electrical infrastructure through regular maintenance and development of a closer relationship with your OEM. This should include annual maintenance on site, up-to-date training for staff and service level agreements to guarantee site emergency response support and a spares and repairs club. Remote monitoring solutions can also be implemented to track the performance of key electrical assets, alerting onsite teams when conditions change.
Finally, keep your wider business targets in sight and make sure that your electrical infrastructure can continue to support changing needs. Whether that’s site growth, just-in-time manufacturing, increased automation or a goal to decarbonise – securing the resilience of your infrastructure will ultimately be the springboard to all of this.
The latest white paper published by Siemens offers insight on building an electrical infrastructure resilience strategy. See link below to download it.