Meet the Propane Generator

A portable home propane generator. (image: generatorhead.org)

Sometimes you hear about people “living off the grid.” What does the phrase mean? That these folks are generating their own electricity, perhaps through wind or solar power, not that they’re living without electricity. After all, modern life — all forms of media, refrigerated storage, and the computer you’re reading this on (and which people “off the grid” need to blog about being off the grid) — depends on electricity.

However, as this winter has shown, for those of us living on the grid, our connection to the electrical lifeline can be a fragile one. Wind, ice, and lightning … these can all take down electrical lines and transformers. And the conditions that take down the lines also make getting the repair truck through problematic — not to mention the difficulty of locating the break, or what happens when you’re the last of 15,000 (or more!) people scheduled to have power restored. If you lost power this winter, you may have spent uncomfortable days shivering in the dark, eating dry pasta and cold canned soup.

Unless, that is, you had a home generator.

A home generator is one of those things that is exactly what it sounds like: it’s a way to generate electricity at home. It converts mechanical motion, produced by burning fuel (see below) into electricity, and provides a way to keep powering all the devices that make life possible (or at least worth living). There are number of options, such as portable generators (wheel it out of the garage when you need it) or permanent ones (hard-mounted), manual start-up models (push a button or pull a cord when you need it) or automatic ones (which cut on when the machine senses you’ve lost power). Yet another decision to make is the type of fuel.

The choices are gasoline, diesel, and propane/natural gas (most generators that run on one can be configured easily to run on the other). And the propane generator offers several advantages over its gasoline and diesel brethren:

• Propane can be safely stored almost forever — not a small consideration in choosing a devices used for infrequent emergencies

• Propane generators require less maintenance, since their fuel does not clog or gum-up fuel lines

• Propane, unlike gasoline or diesel, is often still readily available during a black-out (service stations can’t pump gas without electricity, but you can always take home a propane cylinder from the hardware or home goods store)

• Propane has a lower carbon footprint and is more eco-friendly than gasoline or diesel

• Lower carbon emissions also make propane safer for household use

• Propane has less of a “geopolitical” footprint than gasoline and oil, which largely come from conflicted or occasionally hostile parts of the world.

Of course, nothing is all upside. Even though propane is cheaper than either gasoline or diesel or a per unit basis, it also contains less energy, and so is less efficient. When you factor in the lower efficiency, a propane generator is typically a bit more expensive to run than a diesel one, though a bit less than a gasoline generator.

What does a typical propane generator look like? There’s a picture at the top of this post, and here’s set of specifications for one model suitable for home use.

And not related to propane generators exclusively, but a neat idea that deserves mention: capturing waste heat to improve efficiency. All combustion — burning any fuel — produces waste heat in addition to the expansion of gases that turns the generator’s motor. If that heat could be captured and used, say, to heat water, whose expansion (turning to steam) produced MORE power, that would be efficient and eco-friendly; what’s being otherwise “thrown away” would be put to good use. (Similar in principal to hybrid cars, which capture the waste heat of braking and store it for future use.) That’s what this Connecticut man is trying to do, according to a recent Connecticut Post story.

Finally, in case you’re thinking installing your own gas line, such as a line from a propane tank to a permanent generator, here’s Big Tony the Plumber providing some DIY guidance: