09/18/2008 05:12 am ET | Updated May 25, 2011

Solar Air Heating -- Not Just for Old Hippies?

With record oil profits again in the news and candidate Obama proposing a windfall profits tax to help with winter heating woes, now seems a good time to revisit some old ideas on how best to spend these excess profits. We're all in favor of socking it to Exxon-Mobil and their ilk, some of the most repellent corporations ever to contaminate the earth. Their record profits come mostly from shared national resources, and most of their money is made by selling our national stock of wealth back to ourselves at usurious prices. Sure they make 13 billion in cold hard cash every three months, but pay five billion dollars for an oil spill that decimated one of our most pristine bays? Hell, no!

The last thing we should consider doing is using a windfall tax on oil profits to buy more fossil fuels,
especially since fossil fuels are a "use once and they're gone" proposition, leaving the shackles of slavery in place (and the climate that much weirder). We should instead take any money we can wrangle out of these vampires and put it to work where it will do some good year after year. Two strategies stand out. As with any resource, the first objective should be to use it as conservatively as possible. With heating, this means more insulation. Many older houses can benefit tremendously from additional insulation. The financial return from installing additional insulation can equate to a 40-50% return, meaning a payback in as little as two years and everything else beyond is pure profit.

And this profit is the kind that stays in your bank account, not Exxon-Mobil's.

The second goal should be to try and use renewable fuels, and nothing is more renewable than sunshine. Many folks have never heard of solar air heaters, and those that have might remember the homemade contraptions of yesteryear. But several companies now manufacture relatively inexpensive, attractive, durable, and self-powered solar air heaters that are capable of significantly reducing the heating load for meaningful amounts of living space. An awesome group operating in Minnesota uses federal heating assistance funds to install solar air heaters on lower-income housing. Talk about right livelihood! These people rock!


Many solar air heaters come with a photovoltaic panel and a small fan. When sun hits the PV panel, there's enough heat in the panel to make it worthwhile to blow it into a room. Since the hot air panels have an integrated power source, they are very simple to install. This obviates the need for an electrician and means many homeowners can install panels themselves, or a local carpenter or HVAC worker can be hired to do the job.

We can hear the economists already! They're calling us communists that wants to destroy our beloved economy. Don't we know that if people have free, renewable energy to heat their homes they'll spend less on fuel and our economy will shrink? Don't we know that unless a good is traded, it has no value, so that this free heat we are proposing for our fellow citizens is actually of no use to them? How stupid are we? Uh oh, was that a knock on the door already?

Our friend Dan had a term for this - folks who think in this manner are graduates of the School of Opposite Thinking, or "SOTS," for short. Nearly every economist believes that a growing economy is a good economy. But what measure is used to gauge the health of our economy? Simply how much money we spend. It doesn't matter if we spend it on things we don't want, it's still good. If we all spend more money on tobacco, big cars, and fatty foods and then we spend way more money on our ruined health, then Yay! the economy appears that much bigger!

This flawed analysis extends into our use of renewable energy. First off, it distorts the picture by assigning value to renewable energy that can be traded while assigning no value to renewable energy that is produced and consumed at home. We heat our home, heat our water, and cook our food with solar energy. But because we don't pay anyone, it doesn't make it into any stats for renewable energy use. Just try getting anyone to fork over dollars for a Renewable Energy Credit (REC) for your domestic solar hot water!

Secondly, since on a domestic level of production, renewable electricity can be traded, it is hyped more than solar water or air heaters. Unfortunately, solar electricity is only around 15% efficient while using solar for heating is close to 60% efficient. And since using solar for heating things is simpler than turning it into electricity, it makes installs cheaper as well. So a dollar spent on solar heating goes about seven times as far in displacing fossil energy use than solar electricity. Oh, but we forgot, domestic solar heated water and air can't be traded. If you're interested in a system of economic measurement that actually takes the welfare of its citizens into account (as opposed to just the balance sheets of its corporations), read up on the Genuine Progress Indicator. And when we hear a presidential candidate propose adopting such an Indicator, then we'll know we have a candidate who actually cares about his/her people.

Stephen and Rebekah Hren are the authors of The Carbon-Free Home: 36 Remodeling Projects to Help Kick the Fossil-Fuel Habit from Chelsea Green. For more information about green living, the Hrens, or their book, visit