The two billion tonne carbon challenge

We need to think about 2050 today

When it comes to hitting our 2050 carbon targets we simply cannot wait for the ‘perfect’ solution to present itself – the simple sum is that the earlier you start the less you emit, and we can do so much with the tools at our disposal right now.

Hydrogen is often referenced as the ‘silver bullet’, the one technology that could solve our heating and transport demands but the fact is it remains a high cost option, requiring either large volumes of very low carbon electricity or carbon capture and storage. It won’t be viable to be deployed at scale for some years to come.

Should we wait for hydrogen at a time when action is required today?

Because what we do have today is a legacy of poorly-insulated homes contributing about 2.7 tonnes of carbon per home per year (over two billion tonnes of CO2 between now and 2050 if we carry on doing what we are doing now). And that’s just using the domestic figures, never mind commercial.

Currently there is a lack of supporting governmental policies, with numerous interested stakeholders spanning several government departments. To accelerate the decarbonisation of heat we need the Government to incentivise rapid growth in energy efficiency, digitalisation of the energy system and low carbon heat sources. With the right environment we can absolutely achieve rapid decarbonisation of heat over the next decade.

So where do we start?

Energy efficiency matters. The majority (around 14 million) of properties in the UK carry an energy efficiency rating ‘D’ and consume twice the energy of an ‘A’ rated building. By 2050, 95% of homes will need to be ‘A’ rated.

New builds have an important role to play here. Each year a further 143k new houses and flats are built (which could easily rise to 300k). Establishing high efficiency, low temperature systems in these properties will pay dividends later and the Future Homes Standard announced in the spring statement is a strong step in the right direction.

Heat pumps and hydrogen

Heat pumps have the potential to be a replacement technology to existing gas boilers, are a good retrofit option and support the transition to a low carbon system. Hybrid heat pumps, which use gas to meet the occasional ‘peak’ heat demand periods offer a potential ‘no regrets’ option.

It’s however worth highlighting that installations need to have two key features. Firstly, the heating system needs to be improved to operate at lower temperatures and secondly the system needs to be ‘SMART’ to limit peak demand.

The Government’s Future Homes Standard will play a key role in supporting the deployment of heat pumps at scale in new builds, providing confidence to the supply chain to invest and innovate to meet this demand.

Low Carbon Heat Networks

In addition to energy efficiency and heat pumps, comes a further ‘no regrets option’ particularly where there is a high density of heating or cooling demand. Significant savings in energy consumption can be achieved where heating and cooling are situated in close proximity. E.ON’s ‘Ectogrid’ for example seeks to create a ‘breathing’ network where heat is used again and again as it passes through the city environment. These enable systems to tap into ‘waste’ heat such as sewage, rivers, tunnels using heat pumps with extremely high Coefficient of Performance.

Heat networks also provide a significant storage opportunity. In times of high demand, networks can store large volumes of energy as well as using ‘phase change’ storage. This can make huge progress into the challenge of smoothing the peak energy demand.

Again the Government could do more to remove barriers to growth, for example reducing business rates on networks and enabling heat pumps to be rates exempt.

What will the system look like to support the transition?

Heating is distinctly seasonal with peak demands being 5 times higher than peak electricity demand, needing c300GW of energy to be delivered at peak. For reference the electricity grid is capable of delivering around 60GWe at peak. Whether you use heat pumps or hydrogen this is a challenge to overcome… technologies such as batteries, pumped storage and smoother consumption can make a huge difference.

Clearly the electrification of heat will increase demand significantly over time – but a considerable amount can be done to meet this expectation. Through building an efficient, low temperature, digitally linked system electrification of heat is achievable.

Written by John Armstrong

John Armstrong is a Chartered Engineer and Fellow of the Institute of Mechanical Engineers, with a degree in Mechanical Engineering and a global energy MBA. He worked at E.ON for 15 years until June 2020, including roles in engineering governance, asset risk and safety, and most recently as Head of Operations for E.ON’s decentralised city energy systems.