Electric and plug-in hybrid car sales will jump to a new global record in 2024 despite slowing growth in some markets, according to forecasts from the influential International Energy Agency (IEA).

The Paris-based forecaster said that 17m battery electric vehicles and plug-in hybrid electric vehicles will be sold in 2024, up more than 20% compared with 2023.

The IEA also said most electric cars will cost the same as petrol equivalents by 2030 as prices drop. Tesla lowered prices over the weekend as it fights to retain its market share amid fierce competition from Chinese rivals such as BYD, its closest contender as the world’s largest producer of battery electric cars.

Carmakers have complained that growth in demand for electric cars is slowing, forcing them to offer discounts to compete. While this could damage some carmakers, lower prices are also likely to accelerate the transition, the IEA said.

Fatih Birol, the energy economist who heads the IEA, acknowledged that sales are stronger in some countries than others, but added that there was clear momentum for the transition.

“Rather than tapering off, the global EV revolution appears to be gearing up for a new phase of growth,” he said.

“The wave of investment in battery manufacturing suggests the EV supply chain is advancing to meet automakers’ ambitious plans for expansion. As a result, the share of EVs on the roads is expected to continue to climb rapidly.”

In the first quarter of 2024 there were more sales of electric and plug-in hybrids (which combine a petrol engine with a battery) than in the whole of 2020, the IEA said.

Hybrids still emit large amounts of CO₂ when in use, although some in the car industry argue that – if used correctly – they are a necessary step to lower emissions until public charging infrastructure improves.

Some countries have concentrated on encouraging electric vehicle adoption: four-fifths of all cars sold in Norway in 2023 were electric. However, policies vary widely, with China and richer European countries generally ahead of the rest of the world, including the US.

The UK was Europe’s biggest electric car market over the first three months of 2023 for the first time, according to Matthias Schmidt, an independent analyst.

The timing of the adoption of electric cars in Europe is heavily influenced by the regulations, as carmakers try to eke out profits from their petrol and diesel models while avoiding fines for failing to sell enough electric cars.

Schmidt said he expected UK electric sales in 2024 to remain equal to or slightly higher than Germany, which has a bigger population. Schmidt said German sales were suffering due to subsidy cuts, and because manufacturers are deliberately holding back sales until 2025, when tougher rules on average CO₂ emissions come in.

“That delay will give Chinese manufacturers a small window to manipulate, because from 2025 the traditional manufacturers will really begin their electric vehicle push in earnest,” Schmidt said.

In the UK the government removed subsidies from privately bought electric cars in 2022.

The Society of Motor Manufacturers and Traders on Tuesday raised concerns about the separate grants for zero-emissions lorries. The lobby group said the grants were not being used because it takes too long to certify that trucks produce zero emissions.