When it comes to forecasting energy usage, power suppliers turn to tried and tested data, looking back at historical figures to predict future demand. For a global pandemic such as the one we’re currently navigating, there is no formula, no data and no way of accurately predicting how much power will be needed. When there are fluctuations in demand, the likelihood of blackouts increases. Paul Brickman, Sales and Marketing Director at Crestchic Loadbanks, explores the role of load banks in keeping the UK’s electricity supply working at optimal levels.
Electricity under lockdown
Life under lockdown has led to a shift in the daily routines of millions of people. Offices with banks of computers and power-hungry air conditioning are closed, factories are operating on a skeleton staff or are temporarily shut, shops and commercial centres are on lockdown. The electrical demands of commercial and industrial settings have lessened significantly. At the same time, the lockdown has shifted the demands of consumers. Data suggests we’re getting up and staying up later, shifting our patterns of energy consumption along with our body clocks, while the massive increase in subscriptions to the likes of Netflix and Disney Plus is also evidence of the trend towards increased power consumption during the evening.
This pattern is being borne out by electricity networks across the globe. In New York, power consumption during the morning rush hour has fallen by as much as 18%, while Japan has recorded a 5% drop in power use during weekdays. In the UK, the National Grid has warned that record low demand for electricity during the coronavirus lockdown could see supply outstrip demand which, in turn, could lead to blackouts.
Why is fluctuating demand an issue?
It stands to reason that blackouts are likely to occur when the demand for electricity exceeds supply. Conversely, too much electricity can also be a problem, causing the frequency on the grid to rise and potentially causing damage to infrastructure as well as problems on local energy grids. The combination of high levels of power generation and low demand can also reduce the energy system’s resilience to sudden changes in frequency, which can lead to temporary blackouts.
In April 2020, just as the UK government announced the extension of lockdown plans, National Grid published a statement which suggested that demand for electricity could fall 20% below normal levels, potentially leading to an oversupply of electricity and subsequent issues with continuity of power. Put simply, the UK may experience blackouts.
Balancing supply and demand
Historically, power in the UK has been supplied by a small number of large power stations, such as coal or nuclear. These huge power generation plants are inflexible, taking hours to shut down safely, reducing their ability to make any fast changes to supply. As supply evolves and the world switches towards greener and more sustainable sources of power, there is even more variability in supply – bringing with it further fluctuations along with an ability to be more responsive to change.
Flexible windfarms can power down quickly, switching off at short notice to avoid overwhelming the grid. Hydropower also offers a solution, harnessing excess energy to pump water into lakes into order to effectively stem the flow of power to the grid. While battery storage is seeing increased investment, further work is needed before it provides a viable solution to storing sufficient energy to balance grid fluctuations. Yet, despite these measures and their ability to be more responsive to changing demand, there’s no denying that the increased prevalence of smaller, intermittent sources can themselves result in varying power outputs and instability in supply. The high frequencies caused by high supply coupled with low demand can be very damaging to the transmission and distribution infrastructure, making HV cables bulge and putting transformers and switchgear under greater strain, as power becomes greater than original directional flow design. This was already an issue in areas of major solar generation, such as the South West.
In ‘normal’ circumstances, the grid’s frequency control demand management programme would help to mitigate these fluctuations. Major commercial and industrial consumers are incentivised to scale back or rapidly ramp-up their consumption of power to balance peaks and troughs. While pre-agreeing this pattern is a plausible option, using it as a way to mitigate risk in times of crisis isn’t something that can easily be achieved. Very few businesses have processes that they can turn up quickly to increase demand to the grid and, with many of the UK’s high-intensity power consumers currently inactive due to shutdown, there’s a declining pool of candidates willing and able to do so.
The role of load banks
A load bank offers the perfect power consumption solution to the issue of oversupply, providing a fast-acting, safe, major energy user that can be easily “plugged” into the grid. In simple terms, they can be used to manage and shed power overloads in order to prevent damage. Excess energy can be diverted from the energy network and power lines into load banks, which can then be safely dissipated as hot air.
Load banks are designed to replicate, prove and verify the real-life demands on critical power systems. As such, they are most often used to test back-up power generators and back up power systems. With modern life absolutely reliant on electricity to power everything from our personal lives to our transport, our businesses to our hospitals, load banks have a critical role to play in ensuring continuity of supply. Their role in shedding and dissipating overloads is lesser-known. Yet, in testing times, none the less valid in terms of ensuring the UK has the power it needs – especially with critical infrastructure such as hospitals reliant on uninterrupted supplies.
Whilst load banks have only recently played a small part for balancing the grid, load bank rental offers a viable, immediate and temporary solution to the issue of oversupply. With stability of supply reliant on the grid keeping the frequency at 50hz, load banks can act as a pressure relief valve, making a discernible, safe and immediate difference in an emergency situation, mitigating the risks caused by oversupply and reducing the likelihood of the UK being left without power.
