Net Zero energy generation by 2035 is ambitious but achievable


As the Conservative Party Conference drew to a close last week, the UK Prime Minister has pledged that all of Britain’s electricity will come from renewable sources by 2035.

Against a backdrop of surging gas and electricity prices leading to several energy suppliers going bust, Boris Johnson’s ambitious announcement not only makes environmental sense, it’s also important for the UK’s economic and growth prospects.

But how can we get there? Wärtsilä’s latest power system modelling illustrates how the UK can feasibly reach its net zero target, at the lowest cost.

Go where the wind blows

Our Front-loading net zero report outlines the immediate priority for the UK - building out the abundant potential for offshore wind energy. While the UK has led the way in offshore wind installation per capita, the current roll out rate is still insufficient for targets to realistically be met. Our modelling shows that - with just 14 years left to meet the net zero electricity target proposed - the UK must triple the speed of deployment from around 2 GW to 6 GW every year, to reach 112 GW by 2035. This far exceeds the new 60 GW target announced in Manchester.

COP26 represents an ideal opportunity for the government and business to redouble their efforts and spur an era of sustainable growth, creating high skilled jobs and new industries in areas with a proud industrial heritage.

Supporting the renewable revolution

Offshore wind can and must become the UK’s dominant energy source. However, only when coupled with 52 GW of flexibility technologies, including battery energy storage and thermal balancing power plants, can the UK achieve 100% renewable energy in the fastest possible time.

A combination of flexibility assets provides the most cost-effective bridge to 100% renewable energy future.

Battery energy storage can respond in milliseconds to meet multiple challenges, from frequency control to short term energy shifting. Our modelling shows that 18 GW of battery energy storage will be required to reach a net zero energy system. Wärtsilä is already facilitating greater renewable penetration on the UK grid by installing 200 MW of energy storage systems as part of Pivot Power’s Energy Superhub model, including projects in Oxford, Kent and the Midlands.

While batteries are vital for the UK’s energy transition, flexible thermal balancing power plants will be of equal importance for a reliable grid to support the electrification of transport, heating and industry. These power plants can ramp up to full load in just two minutes, providing a bridge for baseload during longer term fluctuations in renewable power, for example during extreme weather conditions or periods of peak demand.

Our modelling shows that to build a resilient future-proof power system to support renewables, the UK will need 34 GW of thermal balancing power plants by 2035. The synthetic fuel used is produced from excess renewable power in 35 GW of power-to-gas converters. By working in tandem, our modeling suggests these two technologies represent the best option to the UK’s future renewable energy mix is reliable and resilient.  

Although prominent in today’s energy mix, building new large nuclear energy plants to replace old will prove too costly and slow. Nuclear has a role to play in the future of fossil free electricity but it cannot offer the flexibility required by the grid in 2035, as the UK increasingly relies on electricity for transportation, heating and other industrial uses including green hydrogen production. The UK needs to build a flexible energy system from today, to support rapid expansion of renewable energy and doesn’t increase the price of electricity.

Reaching net zero together

The power system modelling presented in this report shows just one of many pathways that the UK can pursue to achieve net zero power generation by 2035. We believe this represents the fastest and most cost-effective pathway for the UK to achieve its targets.

What is crucial, is that all of these scenarios are discussed and considered at COP26. But even more crucially, as the host, the UK must set the blueprint and lead by example on its pathway to the new 2035 net zero power sector target with a detailed and realistic plan.

The world’s eyes will be on the UK over the next few months. Front-loading net zero should be its main priority. 

To learn more about how Wärtsilä can help you navigate the seas of energy transition please visit:


Tony Meski

Senior Market Development Analyst at Wärtsilä Energy Business

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