Energy: What Actually Matters

It’s not uncommon, when I give public talks about the end of the industrial age, for people to ask me whether I can offer them any hope. Now of course people mean many different things by the very indefinite word at the end of that utterance; some want me to tell them that I was only joking and industrial civilization isn’t really careening headfirst into hard planetary limits, others want me to tell them that when the crash is over and the dust settles, some kindly power or other will hand them an even shinier society than the one we’ve got, and still others will settle for being told that our civilization won’t drop dead until at least a few moments after they do.

To all these I have nothing to offer. Still, there are always a few who simply want to know if there’s some reason to believe that the next half century or so might not be quite as ghastly as it looks. I do have something to offer them, and it’s one of the ironies of our time that the reason for hope I’d like to discuss in this week’s post is also one of the most annoying features of contemporary society: the very common assumption that people in the industrial world can’t possibly scrape by without access to amounts and kinds of energy that few if any of our ancestors would have been able to figure out what to do with.

I’ve discussed more than once in these posts the fact that the average American uses around three times as much energy each year as the average European, to support a standard of living that by most of the standard measures isn’t even as good. That’s relevant to the point I hope to make, but there’s another factor as well. Most of the energy that’s directly used by a household in a modern industrial society consists of highly concentrated fuels and 120-volt alternating current electricity. The forms of energy that are actually needed to support a fairly comfortable human life, on the other hand, consist of food on the one hand, and a distinctly modest supply of relatively diffuse heat for cooking, water heating, and space heating during cold weather on the other.

Mind you, this is what’s needed to support a fairly comfortable human life. Most of our ancestors got by with a lot less, and a good many of our descendants will probably do the same. Still, most of our ancestors, and in all probability at least an equal share of our descendants, would or will see the point in a well-stocked pantry, a working stove, hot water on tap, and a home where the ambient temperature is well above freezing in winter, and it seems reasonable to aim for these things now – particularly because they are a lot less difficult to provide than most of the frankly less important uses of energy that get most of the press these days.

It’s worth being a bit more specific. Producing highly concentrated fuels and 120-volt alternating current electricity at home, in anything like the quantities most Americans use these days, with the sort of resources and equipment most Americans can cobble together readily, is a very challenging task; for most of us, "impossible" would be a better description. Producing the amounts of food and diffuse heat that’s needed for a comfortable lifestyle under the same conditions is a good deal less challenging, and in some situations it’s actually pretty easy. Most current projects for dealing with the harsh constraints on energy supplies in the wake of peak oil have fixated on finding ways to keep the highly concentrated fuels and electricity flowing, and a great deal of highly dubious reasoning and evidence has been trotted out in an attempt to insist that we can keep pipelines and gas tanks topped up and grids humming with power from renewable sources; meanwhile, by and large, the much simpler resources that human beings actually need to survive have been left out of the discussion.

The Green Wizard project was launched, in large part, to offer an alternative to this sort of thinking. We’ve spent much of the last six months talking about ways to produce at least some of your own food in your own backyard, using hand tools and readily available organic soil amendments in place of the extravagantly energy-wasting methods of food production indulged in by current agribusiness. There’s plenty more that could be said on that subject, and I’ll doubtless be saying some of it in passing as my own backyard garden begins another season, but the main focus of the posts to come will be on the other half of the equation: diffuse heat.

And this, dear reader, means that you need to get friendly with the laws of thermodynamics.

That may seem like an unlikely assignment, if only because the laws in question don’t seem particularly interested in making friends. Most popular presentations of the laws of thermodynamics these days tend to stress the negative side of these much-maligned rules. Still, as the word suggests, thermodynamics is simply the branch of physics that tells you how heat moves, and if you’re going to be moving diffuse heat around, you need to know how that’s done. The British musical comedy duo Swann and Flanders made this easy some decades ago by explaining the first two laws of thermodynamics in a lively little song. (The link, I’m sorry to say, will play you the song but won’t show you Swann and Flanders singing it; for reasons that left me utterly baffled, the only copy I could find online has video-game characters dancing around and fighting monsters in tune to the music. And, inevitably, throwing around vast amounts of energy in the form of lightning bolts. Go figure.)

Got that? Okay, now that you’re tapping your toes to the melody, let’s apply it.

One of the pervasive mistakes made by people in the industrial world these days – oh, all right, made by most Americans and a much smaller number of people elsewhere – is the notion that the only thing that matters when you’re dealing with heat is having enough energy to produce it. Every autumn, accordingly, you can go to your local department store and find scores of portable heaters waiting for you in serried ranks, so that you can turn electricity or propane or what have you into plenty of heat wherever you want it. You can do that, but unless you do something to encourage the heat to stay around for a while, it’s not going to work very well, and it’s also going to cost you plenty, because producing heat is only the first part of what matters; the rest of the equation, which is in many ways the most important part, is keeping the heat from leaving the place you put it any sooner than it has to.

This is helpful even if you’ve got abundant fossil fuels or plenty of electricity handy. If you don’t, and you have to get by with the much less concentrated energy available from renewable sources, it’s not helpful, it’s essential. The maxim from my old Master Conserver classes was "weatherize before you solarize," and the principle can be extended: unless you take steps to use heat effectively, if you try to get your heat needs met from renewable sources, you’re basically wasting your time.

So the first and most crucial step in making sure that you have enough diffuse heat in your life to get by comfortably in an energy-constrained future is to do a smarter job of using whatever heat you’ve got. In order to do this, you need to know how heat leaves the places where you want it—your home will do for now; we’ve already talked about the food you cook, and we’ll talk about hot water in a later post.

Swann and Flanders’ useful ditty could use just a bit of modification for our purposes, because the three ways that heat passes from a hotter body to a cooler body – conduction, convection, and radiation – aren’t equally important in green wizardry. Conduction is the most important of the lot, convection gets a look in here and there, and radiation is a minor factor; there’s also a fourth, combined factor, which is nearly as important as conduction, that’s called infiltration. This is air movement through leaks, and it’s the process by which cold air gets into your house. Technically speaking, infiltration is balanced by exfiltration, which is the process by which the nice warm air in your house goes outdoors so it can radiate its heat to the environment; in practice, since infiltration and exfiltration use the same kinds of leaks and can be fixed in the same ways, the label "infiltration" does for both.

This is a huge issue in most American homes – anything from a fifth to a half of the heating load on a house is typically accounted for by losses to infiltration and exfiltration – and in most cases, it’s also far and away the easiest and cheapest source of heat loss to fix. The gear you’ll need are a caulk gun, several (usually, quite a few) tubes of good weatherproof caulk, and an assortment of weatherstripping supplies for doors and windows; a sturdy scrubbing brush, cleaning supplies, and a pair of gloves you don’t mind ruining also belong on the list. Your local hardware store will provide you with everything you need.

If you’ve never used caulk or a caulk gun before, you’ll find detailed instructions in the fourth of the Master Conserver handouts available for free download at the Cultural Conservers Foundation website, and you can also find good instructions in any decent book on home repair. Your goal is to find all the little cracks where air is leaking into and out of your home, and seal them with caulk. There are almost certainly a lot of them: along the baseplate where your house joins its foundations, along the frames of windows and doors, in the little holes drilled through the walls by the guy who installed cable television or internet service, around outdoor water faucets, and the list goes on. Search the inside and outside of your exterior walls, and find every crack and gap; make sure the surfaces are clean, so that caulk will stick to them, and then, to borrow a phrase from one of my instructors, caulk those puppies.

Now of course you’re not going to caulk the moving parts of your windows and doors, since you need to be able to open and close them. (Nonmoving parts of windows can and should be caulked; if the windows are old, they probably leak like sieves.) For doors and windows that open, you need weatherstripping. There’s a dizzying range of products available; most of them haven’t changed much since I studied this stuff in the 1980s – for that matter, most of them haven’t changed much since the 1950s- and 1960s-era home handyman books I collect started to include chirpy little articles on "Saving Money with Weatherstripping!" – but different door and window situations call for different kinds of weatherstripping, so take your time and explore your options. The Master Conserver handout mentioned above has a fair amount of info on the subject, and so will books, new or used, that cover energy conservation at home.

A few other details can help you close off other air leaks. Electric sockets and switches on the inside of exterior walls are often the places where the air that leaks in through openings elsewhere gets into your living spaces; your hardware store will sell you inexpensive foam gaskets that go behind the faceplates to take care of this. The hatch into your attic, if you have one, needs to be weatherstripped, since your attic is probably vented to outside – and if it isn’t, it should be; more on this in a later post – and can leak a lot of heat. Finally, if you’ve got an open fireplace, one heck of a lot of warm air is rising out through the chimney to warm the great outdoors. A set of glass doors or some other way of closing up the fireplace opening when it’s not in use will be well worth your while.

By the time you finish caulking and weatherstripping, not to mention putting in foam gaskets and installing glass doors on your fireplace, you may be wondering how any air is going to get into your house so you can breathe it. With the relatively simple technologies we’re using, that’s not an issue; if you do a good job, you’re probably going to be able to reduce the rate at which air flows through your house by something around half, which means that you’re going to save about half the money that infiltration currently costs you – roughly ten to twenty-five per cent of your heating bill, in other words – without causing any problems worth noticing with air quality.

There are high-tech methods out there that will save you a great deal more. Very thorough sealing is an important part of those methods, and so is air quality remediation. These aren’t things you can do yourself – you’ll need to hire a professional – and you’re going to shell out quite a bit of money to do it, but if you’ve got the funds to invest, free heat for life is a pretty good payback; the Passive House system, which was invented in Germany and has recently taken root on this side of the Atlantic, is one approach about which I’ve heard good things. Still, unless I’m very much mistaken, the vast majority of the readers of this blog don’t have the kind of spare income that would allow them to drop five figures on a passive house remodel, and even fewer will have that kind of money as the economic unraveling of our society picks up speed; furthermore, it’s exactly those among us who don’t have the funds to spare for that sort of project that have the most urgent need to save money and energy just now.

Cutting down on infiltration by caulking and weatherstripping, then, is the first step in getting your home ready for an age of energy limits. Over the next couple of weeks, we’ll discuss some of the other steps: all of them inexpensive, all of them easy enough that the average homeowner or renter ought to be able to do them effectively, and all of them important in cushioning the impact of rising energy costs in an age when most people will no longer be able to afford ignoring what kinds of energy use actually matter.


The book that needs to be listed at the very top here is one I haven’t been able to find: a good clear explanation of the laws of thermodynamics in language that a fourth-grader can follow, with plenty of colorful examples. If there is one, I’d be grateful if someone can point me to it; if there isn’t, there’s got to be a physicist out there who can write one, and I can probably even talk a publisher or two into giving it a look. In the meantime, there’s always Swann and Flanders.

Good detailed instructions on caulking and weatherstripping can be found in almost every guide to do-it-yourself home repair published since the end of the Second World War; your local public library can probably provide you with a couple of good examples, and so can your favorite used book store; review the details and then get to work, and you’ll be in a position to help your neighbors figure out how it’s done. The Master Conserver handouts mentioned earlier in this post are also useful.

If you’re interested in the Passive House system, a visit to is a good way to find out about it.