Since September 2020, National Grid Electricity System Operator (ESO) has issued four electricity margin notices (EMNs), warning that the buffer of electricity supply required to ensure the lights remain on was too small. Before September, no such warning notice had been issued in the UK for four years. As the UK continues the transition to renewable power generation and mass adoption of new technologies changes the profile of electricity demand, utilities must find new, reliable and resilient methods of balancing demand and supply.
Today’s dynamic power industry demands flexible, efficient electricity generation — fundamentals that have been tested as the industry adapts its infrastructure to achieve ambitious renewable energy goals. System reliability remains paramount as the environmental and economic benefits of renewable generation stimulate rapid growth of renewables in the power generation mix.
As the UK retires fossil fuel plants and increases the level of wind and solar generation, utilities must plan and implement strategies to bridge this transition and manage contingencies that balance the intermittent nature of renewables. Foresight and flexibility are key to continuing along this path to decarbonisation.
Innovation projects such as Zero2050 South Wales, funded through the Network Innovation Allowance, seeks to systematically identify, evaluate and test different possible paths to decarbonisation at a regional level and is a good example of the type of strategic thinking that needs to be applied to the challenge of decarbonisation. By highlighting the right investment choices for partners and businesses, helping national and devolved Governments make the right policy choices, and by testing methodologies for a collaborative decarbonisation model at a system level across a region, these initiatives will ensure systems meet decarbonisation goals whilst ensuring reliability.
Throughout this transition, as the UK aims to meet decarbonisation goals and sustain reliable generation no matter the conditions, the ESO will have to call on various technologies for dispatchable generation. Battery storage, reciprocating engines and gas turbines with black start capabilities can support wind and solar generation dips, especially in the face of unpredictable weather patterns and rising electricity demand as a result of new technologies such as electric vehicles.
Battery energy storage will be a long-term player in the grid of the future, albeit scaling this technology remains the biggest challenge. When coupled with wind and solar generation, large-capacity batteries can store excess energy during peak solar or wind hours, dispatching when demand is high. While battery storage technologies have become more cost-effective with significant advancement in recent years, energy storage installations have not kept pace with the closure of power plants.
Reciprocating engine generator technology is also compatible with the intermittent energy supply created by wind and solar. These reliable generators can fill the energy void quickly, often capable of black start dispatch at a low cost, with a flexible buildout, but of course don’t aid the net-zero agenda.
Modern gas turbines can address periods of peak demand or unexpected outages as well. This technology has seen dramatic advancement in the last decade, allowing turbines to ramp up to full load in a mere 10 minutes. During a severe outage, this nearly immediate dispatchable energy is essential to meeting the expected energy reliability demands of society.
Whatever the technology or approach that assists the transition from fossil fuels to increased wind and solar energy, it is essential that utilities and industry come together to plan for the integration of such solutions. Reliability cannot be sacrificed along the way. For overall resilience, the system operators should assess their critical loads and, at minimum, develop detailed plans to meet those critical loads.
The influx of EMNs serve as a warning to the UK policy makers on the implications for 100% carbon-free energy goals and the significant infrastructure shift that is required. Without close attention to the integrity and reliability of the grid, gaps like these will become increasingly more challenging to bridge.