Electric truck startup Volta Trucks has announced it will add three new models for inner city zero-emissions deliveries to businesses and raised its sales forecast to 27,000 units annually by 2025.

Company founder Carl-Magnus Norden told Reuters the expanded model range – trucks in the 7.5-tonne, 12-tonne, 16-tonne and 19-tonne weight categories – is based on customer demands to add to its first model, the Volta Zero.

“Customers have been coming to us asking for” different sized vehicles, Norden said, “so we have an opportunity to be much more ambitious.”

The company had previously announced a production forecast of 5,000 units per year by 2025.

Norden said the company should announce large new orders in the coming months and launch another funding round this year. Earlier this year, the company announced $20 million in funding from investors, including investment firm Luxor Capital.

Stockholm-based Volta Trucks, which also operates in the UK, plans to start production of the Volta Zero, a 16-tonne electric truck, in 2022.

The company currently has an order book of $260 million and its biggest public order to date is for 1,000 trucks from French refrigerated truck firm Petit Forestier.

Norden said the largest new truck model should start production in 2023, with the two smaller models likely coming in 2024. He said apart from looking at major European markets, the company will take its demo model Volta Zero to the United States this summer.

Tightening CO2 emissions targets in Europe and China have combined with improving battery technology to provide greater range at lower costs, making commercial electric vehicles more attractive.

Volta Trucks has picked U.S. electric bus maker Proterra to provide its batteries.

Proterra is going public through a merger with ArcLight Clean Transition Corp, a special purpose acquisition company (SPAC).