My sister, the Budding Locavore, has been recently working on putting in a garden with some friends of hers. While she was waiting on someone else to come up with a rototiller, I told her that I had one that she could borrow, to which her response was that I am "made of win and topped with awesomesauce." A little further in on her post, though, she says:

It's electrical in nature, which is a bit odd

Yep, I admit it is a bit odd. It is odd enough that I had to search high and low to find one like it. You see, I'm one of these screwballs that is not really satisfied with the status quo and will find ways to do things that I think are better, even if they come along with their own sets of problems.

In this case, the problem that comes along with it is providing it with electrical power. You have to use an extension cord to power it. For me, this is not a really big issue, because I have over 100m of extension cords in various weights at home, because, put simply, I use electricity for everything. Well, almost everything. I still drive a gasoline-powered car, but only because electric cars are out of reach.

Why?

In a nutshell, here are the things you have to deal with if you use a gasoline-powered lawn mower, rototiller, hedge-trimmer, chainsaw, whatever:

• Fuel
• Exhaust fumes
• Noise
• Oil
• High complexity

By comparison, an electrical appliance has these problems:

• Lower power ceiling (i.e. you max out at about 2 HP ? you might be able to get up to 4 HP in some places, such as Europe, where a higher voltage is used)
• Power cords

Interestingly enough, Ryobi, who manufactured my rototiller, also make a gasoline-powered one on the same chassis. It uses a two-stroke engine (these are the ones where you have to mix oil into the gasoline) and develops 1.3 HP. Being a two-stroke engine, it will most likely eat spark plugs for lunch and stink to high heaven. In comparison, my electric rototiller, which cost $10 less, develops 2 HP and the only local byproduct is the hot air that blows out of the back of it.

Electric motors have some additional advantages over fossil-fueled motors.

First, electric motors are in a natural stable equilibrium. Loading an electric motor will cause it to draw more energy to compensate, all by itself. As load approaches infinity, so does the draw (though physics prevent this from ever actually happening). If it is lightly loaded, it will naturally draw less energy.

By comparison, a gasoline engine needs a system of governors to keep it in equilibrium. They are naturally in an unstable equilibrium state, so that an increase in load will be accompanied by a decrease in output, causing the engine to stall. The governors can increase the fuel flow to counter this, but there is a limit to how much they can do.

With a fully stopped rotor, an electric motor produces its most torque, and an internal combustion engine produces its least. As such, any gears used can be fixed (i.e. you don't have to shift them) and you can often get more work done with a smaller electric motor than a larger internal combustion motor.

Next, there is the matter of efficiency. Internal combustion engines top out at around 30% efficiency. 70% of the fuel entering the engine leaves as heat. Electric motors top out at (and, in fact, typically get) around 95% efficient.

"But wait!" I hear you saying, "Doesn't the electricity come from fuel-burning power plants?"

You're right. Power plants, however, rarely use internal combustion engines, running instead on steam, gas-turbine, or combined cycle (gas turbine + steam) engines. These may get as efficient as 55%. Combined with the energy efficiency of the electric motor, that comes up with a somewhat naïve fiture of 52% efficient (The naïvité stems from the fact that there is some energy lost in transmission);but wait, there's more!

In addition to that, some electricity is not from fossil-fuels! That's right, some of it comes from wind, nuclear, hydro, and occasionally even solar power. If you are a greenie like me, you may be aware of the fact that you can specify this from your utility in some locations. I pay a premium of 1¢ per kilowatt-hour for electricity that is 60% wind and 40% hydro. For a 2¢ premium, you can get 100% wind. As such, using electricity breaks the tight coupling between what you are trying to do, and the imports of foreign oil.

So, in the end, I use electricity for a lot of things. I'd drive an electric car if I could (I believe the fastest-accellerating American-made car is the Tesla Roadster, which is electric and goes from 0-60 in 4.0 seconds). I use electricity for anything else in my house that moves, and the results are cleaner air, not just here, but everywhere, and my neighbours don't care if I mow the lawn at 7:00 on a Sunday morning :)