Coffee heat rising

Solar and rocket stoves: Survival Gear…Frugal Extreme…or Just Going Green?

Okay, so Armageddon is here and the power has gone out…permanently. Your shiny glass-topped stove doesn’t work, neither does the oven, and you have to cook all those pizzas in the freezer before they spoil! What’re you gonna do?

That’s easy: whip out the tinfoil and a couple of cardboard boxes, and build yourself a solar oven! Alternatively, you could build an oven that uses sticks of scrap wood for fuel.

This morning a reader commenting on the Weather! post remarked that it’s very easy to construct a solar oven. So of course I had to check that out. A quick Google search brought up this amazing site. By golly, you can build a solar stove that looks like a nun’s headgear turned upside down. You can make one out of an old innertube. You can make a portable stove out of an umbrella. You can make them out of cardboard boxes. You can even use a pizza box. And if you really want to get fancy, you can hook your stove to a kind of battery-run equatorial mount so it will track the sun all day!

Would one of these contraptions save us cheapskates money? It might, if you have an electric stove. The stove and oven are big energy hogs, especially if you cook indoors all the time. My power bill was $57 last month, and I didn’t turn on the heater or an electric space heater once. I rarely leave the lights burning in unattended rooms, and I only do a couple of loads of laundry a week. My stovetop is gas, but the wall oven runs on electricity. So most of the power had to have been used by the oven, the refrigerator, and the computer. Let’s say four appliances consume the lion’s share of the power (this is just a guess!): $57 ÷ 4 = $14.25.

So. You could stand to save as much as $14 a month by cooking everything bakeable in a solar stove.

Green? Well, except for the mining, manufacture, and hauling of aluminum foil and the wood-pulping, manufacture, and distribution entailed in making cardboard boxes, I suppose it’s green. It would be that much less coal mined or oil drilled. I suppose. Though the energy to make those products has got to come from somewhere.

Hey! Every little bit helps! Eh?

So, what could you cook in such a device? A little cruising shows that cooking is plain and time-consuming. Apparently a solar oven is the (relatively) green equivalent of the slow cooker. Cooking times depend on the kind of cooker you’ve built and, of course, the weather. Roasting a single acorn squash will take you four to six hours. Chicken is said to take anywhere from one to three hours. A pan of lasagne takes three hours, but rice (we’re told) can be cooked in half an hour or so—after the water comes to a boil. One enthusiast cooks beans (all day long) and beer bread in his solar oven.

So if you have some food laying around, come Armageddon, you should be OK, assuming you’ve also laid in enough tinfoil.

Scrolling down at the site of our original discovery, we come across something called a rocket stove. This gadget, built of old cans, barrels, bricks or whatnot, is designed to burn small pieces of wood, such as twigs, scraps, or other small pieces of combustible material. These things can be fairly large—here’s one used to cure tobacco—and certainly could be designed, with care, into a nice backyard bread oven.

From what these authors say, apparently a rocket stove can generate some pretty intense heat. A solar oven? Maybe not so much.

On the other hand, given a 118-degree day a solar cooker might get up some pretty fair heat. It’s already in the 90s here. Maybe later this summer I’ll give one of these gadgets a try.

Has anybody built a solar oven or a rocket stove? How did it work for you?

Rent-a-solar-panel

In this month’s Scientific American, writer Christopher Mims reports that a few enterprising businessmen have figured out a way around the daunting cost of installing solar panels on private homes: don’t buy the things—rent them.

It’s a brilliant idea. Here in Arizona, where a cloudy day is so rare as to elicit excited news reports from local television stations, the one thing that keeps people from covering their rooftops with silicon is the breathtaking expense. My electrician, who solarized his own home, said it would cost $30,000 to switch my house to solar power. It nets out to around $17,000 after various government rebates. But still…

That’s a lot of $300 summer power bills, and, as much as I’d dearly love to get off the grid, it’s way more than I can afford pay for a principle.

One of these outfits, SolarCity, proposes to install the panels on your home for nothing and lease you the equipment. The combination of a reduced power bill and the monthly lease payment represents a significant savings on your power company’s bill (or so it is claimed). And SolarCity points out that on average power companies have been jacking up the cost of electricity about 5 percent every year, so if you lock in your rate with a several-year-long lease agreement, your effective savings increase at 5 percent a year.

In a slightly different spin on this idea, SunRun, a company based in San Francisco and serving Northern California, charges around $1,000 up front and then sells you the power. Power costs, we are told, should be less than or about the same as your power company’s, but one way or the other, you get that comforting self-righteous feeling of powering your home with “clean” solar energy. It would be good to know what’s involved in the large-scale manufacture of solar panels and their ancillary equipment, but for the nonce we won’t look too hard at that issue.

Apparently a number of cities and states are also experimenting with ways to make retrofitting your home affordable, and many will provide rebates for residents who install various kinds of energy-efficient devices. Mims reports that Berkeley and Boulder will lend homeowners enough to pay for solar panels and installation, allowing them to repay the loan over 20 years as part of their property tax bill. There’s no sign of these programs at either city’s site, and so it’s impossible to tell whether such programs, if they exist at all, would save you anything month to month.

At this time, the cost of rooftop solar still exceeds the cost of buying power from a local utility. For me, that’s the bottom line: my summer bills are already way more than I can afford, and they never will go down. I don’t like leasing, which resonates of debt payment. And I’m certainly not going to lock myself into another $30,000 worth of debt slavery to install my own system. But I might put those compunctions aside for a no-money-down arrangement that would guarantee lower power bills than what I pay now.

Unclear what happens if you sell your house while you’re in the middle of a lease with an outfit like SolarCity. It would not be good if you had to pay the whole cost of the solar array out of the proceeds of the sale.To recover it, you’d have to jack up the sale price about 30 grand—good luck with that, anytime in the foreseeable future! Since yours would be the name on the lease, transferring the monthly payments to the buyers would be problematic: if they default, you could end up having to pay for their power until the lease expires.

What’s your take on this? Would you lease a solar power system from a private company?