Engineer – Commentary: Integration of battery storage with Hornsea 3

Every day, up to 50 per cent of the UK’s energy could be renewable, with the offshore wind industry providing a significant proportion of this renewable energy. Offshore wind is a UK success story, being one of the most mature markets in the world, generating enough electricity by 2023 to power 14.2 million UK homes.

But more needs to be done to address the growing impacts of climate change. Increasing renewable energy is key for the UK to meet its legally binding Net Zero target, with the UK Government committed to supporting the construction of 40GW by 2030 and 50GW by 2050.

Massive infrastructure projects like the one I manage, Ørsted’s Hornsea 3 – the world’s largest offshore wind farm – are key to achieving these goals. Hornsea 3 has a capacity of 2.9GW – enough to power over 3 million UK homes.

Intermittent: Renewables’ Biggest Challenge

To reach Net Zero by 2050, the UK really needs to step up to increase its offshore wind capacity. However, because of the mismatch between how we use electricity compared to when it is generated, we already face challenges around how it is transported through the national grid, and how and when it is consumed.

Renewable energy is clean and unlimited, but it suffers from intermittency. The UK grid was designed to accommodate controlled (or dispatchable) centralised fossil fuel generation that could respond in real time to changes in electricity demand. The growth of variable renewable generation in the system, necessary to meet Net Zero targets, is displacing these high-emission but dispatchable conventional generators. This means that the operation of the grid or ‘system’ will need to be more flexible and use new sources of dispatchable technology.

In other words, what happens when the sun isn’t shining for the solar panels or the wind isn’t blowing to turn the turbines? It’s also a problem in reverse—when there’s too much wind (often when we’re asleep) or too much sun (at midday, when we don’t need to turn on the lights). That’s why battery and other energy storage technologies are changing the game for renewables.

Strengthening energy security

The introduction of battery energy storage solutions is therefore key to solving the problem of variability in renewable energy supplies.

At Ørsted, we have just announced our investment in a battery storage system for this very reason. It will be co-located with the Hornsea 3 Onshore Converter Station – where the power is converted from HVDC (high voltage direct current) to HVAC and fed into the grid. It uses our existing grid connection and will help reduce the variability of the UK’s energy supply. It will draw power not only from our own wind farm, but also from others being developed off the coast of East Anglia. It should also make the energy systems more manageable, helping to smooth out fluctuations in supply and demand.

The battery storage system has other benefits, including support for regulating the frequency and voltage of electricity in the grid, through the ancillary services market, and services that support the restoration of the grid in the event of a major power outage. All of these services are essential to the operation of the Net Zero grid.

Unlocking the power of renewable energy

Delivering a range of projects on a project of this size is an engineering challenge on a grand scale. What I find most interesting is overcoming the complexity. But it’s the challenge of taming that technical complexity that gets engineers like me out of bed. Technology in the electrical system is changing at an incredible pace – innovation is rampant, and solutions to problems that seemed out of reach just a short while ago are now within our reach.

Hornsea 3 draws on experts from across a range of engineering disciplines, as well as new technologies and storage systems. We are also working with government, regulators and industry on how to integrate increasing levels of renewable energy into our national grid system to drive the transition from fossil fuels to clean energy.

At Ørsted, we want to see storage technologies mature and develop, including long-duration energy storage that can store energy reserves for days, weeks or even months. We believe in pursuing a variety of energy storage projects to test and innovate new technologies and contribute to the growth of energy storage at the lowest cost.

Luke Bridgman is Managing Director of Hornsea 3 Offshore Wind Farm