How to Unfuck the Planet: Electric Lawnmowers (Sources and Math)
Welcome to the sources and math document for How to Unfuck the Planet: Electric Lawnmowers.
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My Math
How long to recoup the price difference between an electric and gas lawnmower?
The average american lawn is about 1/4 acre (about 1011 m²). The electric lawnmower has a max range of 1/2 acre and the gas lawnmower has a max range of 1/4 to 1/2 acres. We’ll give the gas mower the benefit of the doubt and assume it has a max range of 1/2 acres. The gas mower has a tank size of 1/4 litre or 1qt and the electric mower has a battery of 6.0 Ah at 40V, so a total capacity of 0.24 kWh. Assuming an electricity cost of $0.13 per kWh ($0.10 US), the electric lawnmower costs $0.0624 per acre or $0.0156 per mow ($0.049 US, $0.012 US). With the minimum 2021 gas price in Ontario(at time of writing) of $1.48 per litre ($1.17 US), the gas mower costs $0.74 per acre or $0.185 per mow ($0.59 US, $0.15 US). The gas mower costs almost 12 times as much (11.8589744 times exactly) per mow and by switching to electric, you’ll save on average, under the best possible circumstances for gas, $0.1694 every time you mow the lawn. This doesn’t seem like much, but assuming you mow your lawn weekly from May 1st to October 3rd, you will have mowed your lawn 23 times (this is with 2021’s calendar) and saved $3.8962 ($3.09 US). At this rate, it’ll take you about 5 years to make back the $21 extra.
My Sources
How often does the average american replace their car?
Lawnmower emissions
I couldn’t actually find the original EPA study, but here’s a Scientific American article that references it:
Is the cold bad for batteries?
This one says no.
But this one says they should be kept above freezing.
https://askinglot.com/how-do-you-store-lithium-batteries-for-the-winter
