How much CO2 to produce the electicy used to power an enviromwer for 1 hour?

Question

I am hoping to compare the amount of CO2 produced by a petrol powered mower and a battery powered enviromower.

Answer 1

Well, it really depends on the type of power generation and amount of power used.

Wind, Zero,

Water, Zero.

Coal, a little.

Oil, a little

Tide and Geothermal, zero

Solar, Zero.

Another difference to consider is that Petrol powered mowers have NO catalytic converter.  Its emission is FAR more than dirty than your typical car.  An average mower running for 15 mins generates almost as much pollution as a 2.5 L car running for 1 hour.  So, it is NOT just the CO2 but other pollutants as well.

I used to have a battery powered electric mower.  It worked well up to 1/2 acre.  Anything bigger than that, I would have to wait for the recharge.

Answer 2

An electric mower ultimately requires the same amount of usable energy as a gasoline mower.  A gasoline mower provides that energy with about a 10% to 15% efficiency.  The electric grid averages somewhere around 40% efficiency, but may be closer to 50% during peak usage hours (due to the use of highly efficient on-demand generators).  An electric mower makes use of about 80% of the energy it receives, for an overall efficiency of 37%, which is a good 3 times better than the gasoline mower.

This means that the electric uses a third of the energy that the gasoline uses.  But, only about 70% of energy in the US comes from carbon based fuels, so we need to multiply that 0.33 by 0.70 to get 0.23.  So an electric mower connected to the average outlet in the US produces only about 1/4 of the CO2 of a gasoline mower.

And that's just running it off of the average plug.  For example, I know that about 80% of my electricity comes from nuclear, and the other 20% comes from very efficient gas turbines.  For my plug, it's more like 0.2 * 0.2 = 0.04 (4%).  So an electric mower connected to my outlet would release about 1/20 of the CO2.

Now, most mowers would use up about 3 lbs of gasoline in an hour, which would make about 12 lbs of CO2.  So a gasoline mower makes 12 lbs of CO2, while the average electric would make 3 lbs.