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Using Tractor Supply as an example, they currently sell 21"-22" gas push mowers for $239 to $599, while battery-electric ones of that size range from $449 to $749, with 1 or 2 batteries included (and smaller ones without a battery are as cheap as $179). For $199, you can get an electric corded 20" push mower. (We know of two Middlesexers who've used corded mowers with great satisfaction.)
As an example, Washington Electric Coop currently charges 22.22 cents per kilowatt-hour (kwh). To charge my 7.5 amp-hour battery takes about 0.9 kwh, or 20 cents. That works out to about $1 to mow for 4 hours. (My gas mower used about 0.75 gallon of gas over 4 hours or $2-$3.) An electric mower does not use an air filter, oil, spark plug, or carburetor. Lithium batteries do eventually lose some of their capacity, but a replacement likely won't be necessary for a number of years. They can be recharged hundreds of times before losing even 20% capacity.
Several companies (e.g., EGo, Ryobi) now sell product lines of yard tools that all use the same battery, and they sell their tools without batteries so you aren't forced to shoulder that cost every time
We ourselves haven't used riding electric mowers, but they are gaining traction; they're available at big box stores and Ace Hardware carries a 56" zero-turn mower with 40 amp-hours of battery for $5,500 (compared to gas ones they sell for $3,200-$4,400).
Electric push mowers come with various battery sizes, typically running for anywhere from 45 to 90 minutes on a charge. As you acquire other tools, consider buying one of the same brand that includes another battery to double your mowing time. The time to recharge depends on the size of the battery; a smaller one might take 30 minutes and a larger one a couple of hours.
Electric mowers are simpler machines than gas mowers, with many fewer moving parts. They also tend to be lighter-weight. As a result, assuming comparable craftsmanship, we'd expect the electric mower to be at least as durable. Many established brands (e.g., Ariens, Husqvarna, DR, DeWalt, Stihl, Toro) with known track records now produce them.
Self-propelled electric mowers are commonly available, and their relatively light weight facilitates navigating steep terrain. Tall, thick grass and other heavy material can all be tackled. With a smaller battery mower, I find it good to keep my grass from getting very tall; if it gets ahead of me, I raise the deck and mow again a few days later.
Fossil fuel-generated electricity is not good, but the extra environmental costs of refining gasoline, extra transportation, & wasteful, inefficient combustion in a small engine make this option even worse. The good news is that most of the electricity in Middlesex is from renewable sources, so you can rest easy. If you have solar panels, they're a great complement to electric yard tools.
While we'd usually agree that it's better to keep using a tool if it ain't broke, consider the effects of a gas yard tool: they pollute the air many times more than a gas car, contribute to climate change, disrupt the neighborhood with noise, and are potentially dangerous (high heat can burn you/your home; leaking fuel/oil contaminate groundwater).
Agreed! Perennials, permaculture, mulched paths, vegetables, or letting grasses go until fall for a single mowing are all other options.
The Energy Fair! Listings for similar events appear in Green Energy Times and Mow Electric.