Energy Efficiency

Energy efficiency is critical in minimizing energy demand growth. Efficiency measures can be quickly implemented and scaled up, and play a pivotal role in curbing energy demand and emissions. In the building sector, efficiency measures include large-scale retrofit programs and adoption of minimum energy performance standards for appliances. In the transport sector, there is a rapid shift towards more efficient electric vehicles (EVs), and efficiency in shipping and aviation improves with more efficient planes and ships. In the industry sector, energy management systems, best-in-class industrial equipment, and waste heat recovery options are exploited for maximum energy efficiency.

Behavioural Change

A wholescale transformation of the energy sector cannot be achieved without active and willing participation from citizens. Behavioural change refers to changes in ongoing or repeated consumer behaviour which impacts energy service demand or the energy intensity of an activity. Key behavioural changes in the NZE (Net Zero Emissions) include reducing excessive or wasteful energy use, transport mode switching, and gains in materials efficiency through recycling and improved design. These changes require active involvement of citizens, clear policy support, high-quality urban planning, technical innovation, and increased recycling in society at large.

About 75% of emissions reductions in the Net Zero Emissions (NZE) scenario come from government-led changes and infrastructure development, such as shifting to rail travel, supported by high-speed railways. The rest stem from voluntary energy-saving habits, primarily in homes, with public awareness campaigns playing a crucial role. These behavioural changes are expected to reduce energy-related activity by 10-15% on average by 2050, lowering global energy demand by over 37 EJ in 2050. Around 1.7 Gt CO2 emissions are predicted to be avoided in 2030, with 45% coming from transport. In 2050, most emissions reductions are expected in industries, especially those where tackling emissions is challenging.Regional Differences in 

The adoption of the NZE scenario varies widely across regions, influenced by factors such as infrastructure, geography, climate, urbanization, social norms, and cultural values. Wealthier regions typically have higher levels of per capita energy-related activity, and behavioural changes play an essential role in reducing excessive or wasteful energy consumption in these regions.

Electrification and Emission Reductions

In the NZE, using low-emissions electricity in place of fossil fuels drives about 20% of total emissions reductions by 2050. Global electricity demand more than doubles between 2020 and 2050, with the most significant increase in the industry sector. In transport, the share of electricity jumps from less than 2% in 2020 to around 45% in 2050, with electric vehicles (EVs) making up more than 60% of total passenger car sales globally by 2030. Electrification of shipping and aviation is limited but progresses after major improvements in battery energy density. In buildings, efficiency improvements moderate electricity demand, yet with increased activity and widespread use of heat pumps for heating, demand still rises.

Use of Electricity in Hydrogen Production and Future Demand

Alongside the direct use of electricity, its use for hydrogen production also increases dramatically in the NZE scenario. Merchant hydrogen produced using electrolysis requires about 12,000 TWh in 2050. The surge in electricity demand also necessitates significant investments in electricity sectors and efforts to ensure supply stability and flexibility.

Renawables

Renewable energy technologies are crucial in reducing emissions from electricity supply on a global level. The share of renewables in global electricity generation is projected to increase from 29% in 2020 to over 60% in 2030, and nearly 90% in 2050, primarily driven by the expansion of wind and solar energy. Other key contributors in 2050 include hydropower (12%), bioenergy (5%), concentrated solar power (2%), and geothermal (1%). Renewables are also vital in reducing emissions in the buildings, industry, and transport sectors, either directly or indirectly through electricity or district heating produced by renewables. In the transport sector, renewables contribute both through electricity for electric vehicles and through the use of liquid biofuels and biomethane. In buildings, renewables usage increases from about 10% of heating demand in 2020 to 40% in 2050, primarily through solar thermal and geothermal energy. In the industry sector, bioenergy, solar thermal, and geothermal will account for about 40% of the heat demand by 2050.

Hydrogen and hydrogen-based fuels

Hydrogen use in the Net-Zero Emissions scenario (NZE) initially focuses on converting existing uses of fossil energy to low-carbon hydrogen. Global hydrogen use is set to rise from less than 90 Mt in 2020 to over 200 Mt in 2030, with 70% of that being low-carbon hydrogen. This rapid expansion will lead to significant cost reductions for electrolysis and hydrogen storage, enabling hydrogen to balance fluctuations in electricity demand and supply. By 2030, there will be more than 15 million hydrogen fuel cell vehicles on the road.

Bioenergy

Global primary demand for bioenergy, predominantly solid biomass, was nearly 65 EJ in 2020. However, a significant portion was used unsustainably. This is set to change by 2030, with an increase in modern bioenergy to about 100 EJ by 2050, all from sustainable sources. Modern solid bioenergy use is projected to increase by about 3% each year to 2050. By 2050, bioenergy will account for 5% of total electricity generation, 50% of district heat production, and significant portions of the heat for paper and cement production. Bioenergy will also be increasingly used for heating in advanced economies.

Biogas, Biomethane, and Bioenergy

In the NZE, the usage of biogas as a source of renewable energy in rural households is expected to rise significantly by 2030, reaching around 500 million households. This is expected to reduce emissions from inefficient combustion and waste decomposition, and provide employment and income for rural communities. Biomethane demand is predicted to grow to 8.5 EJ, replacing natural gas as a source of process heat in industries, due to blending mandates for gas networks. In addition, liquid biofuel consumption, primarily used in road transport, is set to increase, with bio-kerosene constituting about 45% of total fuel use in aircraft by 2050. Bioenergy can leverage existing infrastructure and is critical in offsetting emissions in sectors where full elimination of emissions is challenging.

Carbon Capture, Utilisation and Storage (CCUS)

CCUS plays a vital role in transitioning to net-zero CO2 emissions by addressing emissions from challenging sectors, scaling up low-carbon hydrogen production, and enabling CO2 removal from the atmosphere through BECCS and DACCS. Policies support measures to establish markets for CCUS investment and encourage shared CO2 transport and storage infrastructure. In 2050, about 10% of total bioenergy is used in facilities equipped with CCUS, capturing around 1.3 Gt CO2. In the NZE, around 7.6 Gt CO2 is captured globally by 2050, with 95% stored in permanent geological storage and 5% used for synthetic fuels.

Role of CCUS in Different Sectors

In the NZE scenario, energy-related and process CO2 emissions in industries account for almost 40% of the CO2 captured in 2050. CCUS is particularly critical for cement manufacturing, which has high process emissions. The electricity sector accounts for nearly 20% of the captured CO2 in 2050. Retrofits in coal-fired power plants and gas-fired plants equipped with CCUS play important roles in emerging and advanced economies respectively. By 2050, about 50% of the CO2 captured comes from fuel transformation processes like hydrogen and biofuel production. The rest comes from Direct Air Capture (DAC), which is scaled up from pilot projects today to capture 1 Gt CO2 per year by 2050.