This is how carbon emissions from the UK’s electricity network could become negative by 2033

By 2050, Britons and their electric cars could be key players in the UK’s low-carbon energy system. This is according to a series of scenarios published by the UK’s energy distributor, the National Grid. It suggests that reaching net-zero emissions by 2050 is achievable, and that UK carbon emissions from the electricity grid could become negative by 2033.

Achieving this will depend on immediate action around a series of determinators. These include increasing the share of renewable energy, building industrial-scale carbon capture and storage (CCS) facilities; and scaling hydrogen production and usage.

The National Grid also emphasises that the energy system alone cannot deliver decarbonisation. Behavioural changes from end-consumers – at home and in industry – is vital to making the shift.

Renewable energy eats away at fossil fuels

Renewable energy has been a success story in the UK and Europe. So much so that in the third quarter of 2019 it overtook fossil fuels like coal, oil and gas for the first time, and generated more than 40% of the UK’s energy. Half of this came from wind power, which is not surprising given that the UK has the largest installed base of offshore wind.

However, at least 3GW of wind and 1.4GW of solar farms need to be built every year until 2050 to raise this level up further, with a view to renewable – or “zero marginal cost” – generation delivering up to 71% of energy output by 2030, and 80% in 2050.

A key challenge for the switch to renewables – in the UK and elsewhere – is intermittency: depending on the weather, renewables may either not produce enough energy to satisfy demand, or too much for the grid to absorb.

Storage of this excess capacity is a challenge for the energy transition.

Utility-scale and home-size batteries are options, but the installed capacity is still low. However, one area where battery volumes are growing rapidly is electric vehicles (EVs). The number of EVs on the road around the world is predicted to increase by 36% over the next decade, opening the doors for so-called “vehicle-to-grid’ (V2G) charging.

Managing energy demand flexibly

EVs could flexibly store excess renewable energy while plugged in, allowing the local network to draw on this stored energy at times of peak demand.

The National Grid sees around 45% of households actively providing V2G services by 2050. Up to 80% will use smart charging for their vehicles, so their EVs can automatically charge at times of low demand (for example during the night), thereby maximising network capacity.

EVs will be part of a much more flexible and decentralised energy system that will replace the monolithic, centralised power generation of old.

In the centralised model, more power must be generated when demand peaks. In a decentralised system, energy users – businesses and consumers – are linked together and their demand is managed proactively to balance out peaks and troughs (“demand response”).

Rocket fuel to the rescue

Another lifeline for renewable storage is hydrogen.

Using a process of electrolysis from water, the first element in the periodic table can be generated without emissions, providing renewable energy is used in the process (“green” hydrogen).

The National Grid sees hydrogen meeting between 21% and 59% of 2050 energy needs, depending on the chosen scenario.

Heating currently accounts for half of global energy consumption and 40% of CO2 emissions. Trials of feeding hydrogen into existing gas infrastructure to replace natural gas, either partially or entirely, are underway, including in Turkey and the UK. Proposals for a pan-European “hydrogen backbone” were announced in July 2020.

The gas also has a wide variety of applications in industry. As a replacement fuel for coal or natural gas, it can be deployed in sectors such as steel and cement, whose processes rely heavily on fossil fuels and can’t be easily electrified. Similarly, hydrogen could be one way forward for long-haul shipping and aviation, for which electrification is not a viable option at the moment.

The catch with hydrogen is that, to date, most of the gas is still produced by methods that do emit carbon (“grey” hydrogen).

Analyst IHS Markit predicts that green hydrogen will become cost competitive with these by 2030. But getting there will require significant policy support. The US, Germany and the European Union have recently launched schemes to develop the green hydrogen market to scale.

Carbon for good

Although green hydrogen is the long-term goal, building scale will require investment in traditionally made hydrogen to meet the demand generated by regulatory incentives until electrolytic production picks up. In its report, the National Grid states that a minimum of 80TWh of hydrogen is required for shipping and heavy road transport alone.

To keep emissions at bay, the European Commission is investing in carbon-capture technology to sequester and store the CO2 generated by traditional hydrogen production (“blue” hydrogen).

Carbon capture, utilization and storage (CCUS) is not only a godsend for hydrogen production but can also help decarbonize existing power plants and heavy industry which can’t easily transition to electricity or hydrogen. The captured CO2 can be compacted and stored, or used in industrial processes.

There are now more than 50 projects underway worldwide, mostly in the US, which has recently launched a new CCUS scheme. Alongside, the UK is investing $1 billion in a CCS infrastructure fund that aims to set up two CCS clusters in the industry-heavy north of the country over the next decade.

Behavioural change is vital

Against this backdrop, the National Grid stresses that energy consumers and their behaviour will be a decisive factor in terms of homing in on net zero.

This means: energy-efficiency measures across the board, switching to decarbonised technologies in industry; the proactive electrification of transport; low-carbon heating systems and smart energy management in residential and business settings.

While government incentives and disincentives may help with some of these, they will also depend on end users investing in their own future and that of the planet.