The Mayor of London Sadiq Khan has issued a wake-up call to government, asking that more support is provided to support efforts to reduce emissions.
It comes as a new report is published by Element Energy, commissioned by the Mayor of London, which sets out four scenarios for decarbonising the capital by 2030.
Whilst all the scenarios – dubbed High Electrification, High Hydrogen, No Constraints and Accelerated Green – share aspects such as greater energy efficiency, behavioural change and greater electrification, they vary in speed and choice of technologies used.
No Constraints is the most ambitious and would see just 14% residual emissions by 2030, dropping to 10% by 2033. This is considered the maximum level of decarbonisation possible, according to the report.
This is followed by Accelerated Green with 22% residual emissions, then High Electrification with 27% and High Hydrogen with 30% residual emissions in 2030. All of these scenarios are more ambitious than the Mayor of London’s 2018 Zero Carbon London: A 1.5°C Compatible Plan, reflecting the target of net zero by 2030.
All four scenarios require significant retrofitting of homes to bring about a 37% reduction in total heat demand. Additionally, retrofitting of non-domestic buildings should reduce heat demand by 39%.
Under the No Constraints, Accelerated Green and High Electrification scenarios, bans on the replacement of boilers would be introduced in 2024, 2026 and 2035 respectively. Such a move would drive up the respective adoption of heat pumps to 3.3 million, 2.2 million and 1.8 million by 2030.
Such increases would require additional policy and funding support, building on the Warmer Homes scheme launched by the Mayor of London. In December 2021, he committed an addition £51 million for the rollout of energy efficiency technologies including insulation, ventilation and heat pumps across the capital.
PV, EVs and flexibility
Solar PV is also expected to play a role in the decarbonisation of both domestic and non-domestic buildings, with the two most ambitious scenarios setting out an installation target of 3.9GW by 2050. This would require more ambitious policies and additional funding and financing, in particular to support community energy projects.
In the High Electrification and High Hydrogen scenarios solar PV is still expected to play a significant role, with a target of 2GW by 2050.
For transport, the No Constraints scenario suggests a ban on the sale of new internal combustion engine vehicles in 2025, ahead of the national target of 2030 included in the other three scenarios. Both this and the High Electrification scenarios would lead to around 200,000 ultra-low emission vehicle (ULEV) cars and 40,000 ULEV vans sold a year year between 2024 and 2030.
It is estimated that 34-40,000 public chargers will be required to meet the demand in this would create, including 4,000-5,000 rapid (50 kW and above) public chargers by the end of the decade. This would be comparable to targets set out in TfL’s recent EV Charging Infrastructure Strategy, the report notes.
It also highlights the need for a broader shift in transport, with more journeys walked or cycled to reduce emissions. Additionally, the Mayor of London is going to look at the potential of establishing a fair road user charging scheme, although the technology required for this is a number of years away from deployment.
The shift in both heating and transport would require network upgrades to accommodate the increased electrification. This will vary between scenarios and will be impacted by the use of flexibility measures such as demand side response (DSR) and energy storage.
Without a flexibility measure, Element Energy found that between three and 50 of London’s 235 primary substations will need to be reinforced by 2030, and that this number will grow to 125 by the middle of the century.
The use of DSR in the No Constraints and High Electrification scenarios would reduce this to six to eight substations by 2030, and around 100 by 2050.
By applying analysis from Imperial College London on the impact of storage and DSR in the UK to London alone, the report estimates that the use of these technologies could save £1.3 to £1.6 billion in upgrades across the scenarios, even when taking into account the cost of implementing the flexibility measures.
Green hydrogen's role
The role hydrogen will play in reducing emissions by 2030 is relatively low across all scenarios, with the High Hydrogen the most optimistic and assuming the conversion of the existing gas grid to enable hydrogen, however this is not forecast until after 2030. This would begin in the early to mid-2030s and be completed around 2045, with total demand reaching 26TWh/year by 2050.
Hydrogen is, however, expected to play a strategic role in all scenarios for areas considered harder to decarbonise.
Since the release of the government’s Hydrogen Strategy in August 2021 activity in the sector has been picking up, with a number of large-scale projects announced around the UK. But it remains a nascent sector with much debate over exactly what role it will play in net zero.
Overall, the cumulative investment cost of the journey to net zero by 2050 for the capital varies from £294 billion for the Accelerated Green scenario to £285 billion for the High Hydrogen scenario, excluding fuel costs. No Constraints requires the most investment in the short term, and is therefore the most expensive when looking at the next decade.
A number of factors could change this however, in particular the carbon price. No Constraints is the lowest cost pathway by 2060, due to the savings created by having low-carbon systems and services in place earlier on. Depending on the level at which the carbon price is set, this could happen even faster, with a high carbon value making it the cheapest as early as 2034.
Meanwhile, all four scenarios lead to job creation that peaks in the mid-2020s due to the need for retrofitting. This could create 32,000 jobs directly, while for heat pumps and district heating deployment, up to 35,000 additional full time jobs could be created at the peak.
However, a skills gap must be breached to ensure this is maximised, with a recent report from the Energy Systems Catapult warning the skills gap is currently holding back decarbonisation.
“This new report must act as a stark wake-up call for the Government on the need to provide much greater support to reduce carbon emissions in London. It’s clear the scale of the challenge means we can’t do everything alone,” said the Mayor of London, Sadiq Khan.
“It’s clear the cost of inaction – to our economy, to livelihoods, to the environment and to the health of Londoners - would be far greater than the cost of transitioning to net-zero and reducing toxic air pollution. That’s why I’m today beginning a conversation with Londoners, local government and businesses about the best way forward to create the green, sustainable city we all want to see.”