While the US is on its way to replacing ICEVs – internal combustion engine vehicles – with electric vehicles, there are millions of small ICEs used for many purposes such as lawnmowers, welding generators, cement mixers, and scores of other portable applications that require independence from the electric grid.
One answer might be that these small ICEs could be converted to run with hydrogen. This eliminates the CO2 from the exhaust gases. But the combustion causes nitrogen oxides, which are also greenhouse gases. So hydrogen conversion is not totally ending greenhouse gases.
The electric motors being made for BEVs – battery electric vehicles – are capable of producing as much power as the auto engines they replace. They’re small, lightweight and getting cheaper with mass production. But the batteries needed to run them are heavy and large and have to be charged. For small ICEs of 6 or more horsepower, it would make sense to build a battery system with a capacity to run the appliance for most of the workday and charge at night. The 6 horsepower is equivalent to 4.5 kilowatts using 750 kilowatts per horsepower.
At this date, October, 2021, some stores are advertising cordless electric lawnmowers for sale. It looks like smaller gas engines will be replaced by electric motors in the next few years.