Low carbon heating biggest household challenge for ‘net zero’

Published: 2 May 2019

Millions more households will have to switch to low carbon heating before 2030 if the UK is to achieve a ‘net zero’ future, underlining the need for new consumer-friendly technologies.

Analysis by Energy Systems Catapult for the Committee on Climate Change (CCC) found meeting a net zero future would require more lifestyle changes for the average UK household in transport, diet and air travel – compared to current (80% reduction on 1990 levels) ambitions.

But perhaps the most significant change would relate to how people heat their homes.

Energy Systems Catapult, chief executive, Philip New, said: “Achieving a net zero emissions target by 2050 would require households to engage more profoundly in the low carbon transition around heat, transport, aviation and diet.

“This compares to current (80%) ambitions – where targets could conceivably be met with hybrid petrol cars and some natural gas boilers still in the mix, and with current levels of meat and dairy consumption, and a near doubling of air travel demand.

“With the average gas boiler lasting up to 15 years, most households will have two opportunities to switch to low carbon between now and 2050. With a tighter target, more homes will have to opt for low carbon solutions sooner rather than later – so we need to make those options attractive to consumers.

“The full decarbonisation of heat requires natural gas to be replaced by greener gases, such as hydrogen, or else electric heat pumps and district heat networks, as well as the greater use of hybrid systems.”

The Catapult explored possible actions for decarbonisation in UK households, using pathways set out by the CCC, showing emissions reduction that can be achieved under three scenarios: Core 80%, Further Ambition over 90% and Net Zero 100% emission reduction levels.

“To meet current emissions targets, most scenarios require rapid cuts to carbon from electricity and waste anyway,” added Philip New.

“Increased ambition in transport, aviation and diet would be a challenge but also an opportunity – since many of the steps involved would bring a number of co-benefits such as reduced congestion, improved air quality, expansion of green spaces and improved physical and mental health.

“The greatest challenge is developing low carbon heating options which are as good, if not better, than current heating technologies.

“That means helping companies develop offers that will give people better control over how they heat their homes, including how efficient their homes are, as well as developing the potential of low carbon gases.

“Choosing the right options and rolling these out at scale will also require a much deeper understanding of different local areas’ energy systems – the state of their housing stock, the capacity of their power and gas grids etc – to ensure a joined-up approach and to keep costs down.”

“Care also needs to be taken when setting policy to ensure the least well off are not disproportionately affected, particularly in the case of low carbon heating.”

The UK Government asked the CCC to assess the impact of a target to reach net zero emissions as the UK contribution to keeping global warming to 1.5C. Energy Systems Catapult has considered the implications of this increased ambition for the average UK household across six activities: heating, transport, electricity, aviation, diet and waste.

Key findings under a net zero future for households include:

  • Heat – comprehensive improvements to building efficiency and adoption of low carbon heating systems in place of natural gas, (e.g. heat pumps, district heating and hydrogen boilers); smart control systems improve consumer experience; greater use of hybrid systems to balance between heat and power systems; and local area energy planning essential to ensure a joined-up approach and avoid unnecessary cost.
  • Transport – all new car sales from 2035 will likely have to be electric (or potentially hydrogen), allowing a 15-year period for any remaining fossil fuel vehicles to retire. Reducing overall distances travelled (e.g. through flexible working) and shifting to more sustainable transport like buses, trains, cycling and walking, are also needed.
  • Electricity – national solutions like large-scale renewables, nuclear, or gas with carbon capture and storage (CCS); significant opportunities for households to provide flexibility to the grid, (e.g. micro-generation and energy storage technologies, or smart appliances that offer demand-side response as part of a future smart grid).
  • Aviation – with around 15% of people responsible for 70% of all flights, there is an uneven distribution for average household emissions. Net zero doesn’t mean an end to flying, but rather preventing aviation demand from growing as fast as it has done historically and requiring offsets elsewhere in the economy. This most ambitious scenario for emissions reduction would see 2050 demand at comparable levels to today, with measures to curb aviation demand by incorporating the cost of carbon into ticket prices. The development of alternative fuels is an innovation priority.
  • Diet/Agriculture – in addition to ‘upstream’ changes to improve farming practices, shifting diets more in line with guidance for healthy eating would see meat and dairy consumption fall by at least 20%, with a significant impact on emissions due to the high global warming effect of methane; while increased moves to non-meat protein alternatives, even possibly laboratory-grown meat.
  • Waste – given the significant cuts already needed in waste emissions to reach 80%, net zero would require only small further reductions, including food waste, to help avoid most emissions arising from landfill.

As the CCC’s analysis shows, even net zero scenarios include some remaining household emissions, e.g. in diet and aviation. Negative emissions (removing carbon from the atmosphere) would therefore be required. But methods for achieving this have their limits, so the more that emissions are curbed directly, the less we will have to rely on these.

To view the full report, click here.

Figure 1: Infographic of UK average household emissions (with historical shares)

Table 1: UK average household emissions across the six activities. Based on ESC analysis.
kgCO2 e 1990 2017 Core Scenario (80% cut) Further Ambition

(90% cut)

Net-zero (demand-led)

(100% cut)

Heating 4,535 2,745 692 138 138
Transport 2,952 2,376 371
Electricity 2,358 755 59 25 25
Aviation 533 1,027 911 724 537
Diet / Agriculture 2,324 1,591 1,343 686 371
Waste 2,050 305 100 87 87
TOTAL 14,752 8,798 3,475 1,661 1,160