Technology’s evolution continues to inspire, but there are also cautionary tales that justifiably make a solid case for methodical checks and balances. The world’s ever-evolving power grids are a good example. A recent half-day outage in Spain and Portugal affecting more than 50 million customers clearly demonstrates how our evolving grids can be impacted by new challenges. Preliminary findings suggest that the incident was the first known blackout to be caused by overvoltage, which occurs when there is too much electrical voltage in a network. Furthermore, according to the report, automatic defence plans were activated, but could not prevent the power system from shutting down.
Balancing supply and demand in real time
In the context of today’s grid infrastructure, flexibility refers to changing consumption profiles and the ability to align them effectively with available generation capacity and supply. Historically, this has been relatively straightforward. South Africa, for example, had in the past relied predominantly on coal-fired baseload power stations. These conventional plants delivered stable, predictable output, making system planning and balancing relatively simple. From a grid management perspective, variability was limited and interruptions were easier to control.
However, the introduction of renewable energy sources has fundamentally changed this certainty. Renewable sources, like wind and solar, are variable and intermittent, fluctuating according to weather conditions and time of day. The transition to a grid that comprises renewables is a positive and necessary move. However, it exposes the grid to far greater variability than it was originally designed to handle. The result is the need for a flexible grid capable of balancing supply and demand with near real-time capability.
Maintaining stability
Resilience describes how the grid responds when something goes wrong. Disturbances can arise from extreme weather events, storms, flooding, earthquakes or unexpected equipment failures such as transmission line outages. The question is how effectively the grid can absorb disruptions.
Here the grid needs a absorber of sorts, like a shock absorber on a bicycle or car, and when a bump is encountered, it dampens the impact to ensure a stable ride. Similarly, a resilient power system must absorb disturbances without triggering widespread outages or system collapse. From a technical perspective, resilience depends on the availability of the right infrastructure and control mechanisms. These include reactive power compensation, capacitor banks for voltage control and frequency stabilisation systems.
DERMS is the logical tie-in
Distributed Energy Resource Management systems, or DERMS, form an important part of establishing a grid that is both flexible and resilient. They can provide utilities and grid operators with the intelligence required to manage Distributed Energy Resources, or DERs, including solar, wind, batteries and diesel generators, in a coordinated and seamless manner.
DERMS allow for real-time balancing of load and generation and help prevent over-generation during periods of low demand while reducing reliance on conventional generation when renewable output is high.
Grid challenges are not limited to power shortages. During periods of mild weather, demand may be low while solar and wind generation are high. Over-generation can overload networks and cause outages just as readily as insufficient supply. Again, DERMS address this by providing the capability to curtail generation when necessary, shift or manage demand, and balance renewable and conventional power sources dynamically. In doing so, DERMS can transform distributed energy from a grid risk into a grid asset, delivering both the flexibility and resilience that modern grids urgently require.
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