Energy From the Roof

Cold water, applied suddenly, can be inspirational.

I was reminded of this Friday morning when, mid-shower and all lathered and shampooed, the gas ran out. It wasn’t a matter of jumping out of the shower, either. I had to rinse it all off first. So I wasn’t just surprised by the icy blast. I had then to deliberately submit to it.

Where I live, there is a good and economical system in place for the purchase of propane. You can estimate how much you’re likely to use in the coming year and, in July, purchase it all at the low summer price. Yes, it’s a gamble, because if the price goes down, you’ve still paid the higher summer price. It’s not much of a gamble, though, because the price never goes down.

Not everybody participates, but I do. The problem was, they didn’t deliver the gas.

The Friday before Labor Day I found a message on the answering machine from the gas delivery driver who said he couldn’t stop by that day but would Tuesday. I didn’t give it much thought, because I hadn’t especially expected a delivery. It just needed to come sometime before I ran out. The 500-gallon tank is outside, so my participation isn’t necessary. It didn’t come before I ran out, six weeks later to the day.

I got frozen at 7:09 a.m. and the gas company opens at 7:30 a.m., and by 7:32 a.m. it had been informed (in terms unusually polite coming from me) that I’d run out of gas. I dried off and went on errands, and by the time I returned, the tank was filled. It having gone completely empty I had to reset the water heater. But I have no appliances with standing pilot lights, so that was it.

When one has involuntarily, and then voluntarily, spent time getting sprayed with cold water, the idea of hot water remains in the mind for a while. First came thoughts of solar water heaters, and the one that came to mind — always comes to mind — is the big black plastic bag and fittings that one gets to hang from the rigging on a sailboat. You would be amazed at how hot the water gets, and how quickly.

There are solar water heaters for home use, too. They vary, from lattices of black pipe you put on the roof and a pump to bring down the hot water and carry up the cold water, to elaborate contraptions that cost thousands of dollars. The former are very efficient at heating water while the latter are even more so while also being efficient at parting the homeowner from his money, at least at first.

In both cases, they’re the most efficient way we have to extract power from the sun. They do it orders of magnitude more efficiently than anything else.

I have friends who have installed solar panels for generation of electricity, and in every case they have been disappointed in the cost compared to the small amount of electricity delivered. While there’s work being done to make them better, photovoltaic systems are not efficient. Also, they wear out in a few years and the homeowner has to pay for new ones and pay to have the old ones disposed of. It doesn’t seem to be a good deal, at least not yet.

Of course, solar water heaters have their drawbacks: It’s not always sunny, and in many places it freezes, requiring a more complicated system filled with antifreeze that circulates through the pipes on the roof, then down through coiled pipes in the water tank downstairs. Even so, it’s efficient compared to other solar-powered appliances.

The sun, as no one doesn’t know, cranks out a lot of heat that hits your house. On hot afternoons, I can feel the heat by putting my hand on a sun-facing wall — and my house is well insulated. Some of the time we would be happy to have that heat. Much of the time we wouldn’t be and aren’t. And when we would be, it isn’t there because it’s winter and the sunlight is weak.

For years I’ve had an idea; I think I’ve even written about it before. What if house paint, and especially roofing shingles, changed color depending on the temperature? I think of this whenever I think about re-roofing the house, which I’ll have to do one of these days.

I like not spending money on energy. You go argue global warming or whatever they’re currently calling it if you want. My objection is to bank account emptying. And what interests me is the idea of thermochromic shingles, or at least thermochromic roof coatings — I might actually prefer a steel or aluminum roof. I had the idea a while ago and now I see such products are actually being made.

What they do is simple: when they get warm, they change color. So you could, ideally, have a roof that’s black in the winter and white in the summer. That would change the amount of heat that is radiated into your home.

By how much? A study I found showed “that compared to common roof (asphalt shingle), thermochromic roof is effective in reducing the building HVAC load demand, which saves up to 40.9% of total energy consumption” in an experiment in San Francisco, California. As the researchers explained, “When the temperature is lower than the transition temperature, thermochromic materials exhibit dark colors and have strong absorption of solar energy; whereas above the transition temperature, they present light colors and feature high solar reflectance.”

Among the findings is that under some circumstances, “The surface temperature of the building is significantly reduced by 8.7—16.6°C during summer and increased by 1.4—2.6°C during winter.” That makes sense because in the winter the sunlight comes at a sharper angle, so the effects are reduced. (Which means that if comfort is important to you and you live where the sun shines and have to choose a color, white is the one to pick.)

There are other studies with similar results. Here’s one. Here’s another.

The stuff comes in various forms, from a spray application on an existing roof to membranes applied atop or instead of existing roofs. It appears that metal roofs with the coatings are available, too.

I do not know if there is variation in “transition temperature” or other factors. Nor is the cost easy to pin down because, well, we’re talking roofing here, done by roofing companies which, deserved or not, do not bask in the warmth of shiny reputations.

Nor do I know if the stuff lasts. A roof that saves you $500 per year is no bargain if it needs to be reapplied for $3000 every five years. It could well be that the difference in winter is so low that a plain white roof would be more cost-effective, and even with a trick chameleon roof white is the best you can hope for in the summer anyway. As the studies show, a dark roof in the winter doesn’t give you all that much.

What most puzzles me is how we’re encouraged, even paid, to adopt far less efficient ways of saving fuel and electricity. Here’s what the IRS says on the subject (phrased in keeping with current IRS rules requiring every word to be incomprehensible). The IRS — well, the bureaucrats and congresscritters who are involved, too — want you to buy a new heat pump, water heater, insulation, window seals, and have someone come round to inspect it all, and all at high cost, part of which you can subtract as a tax credit.

What it ought to say is “paint the roof white and you can deduct the cost.”

I think there’s probably some corruption involved. Do you remember when Barack Obama was singing the praises of the solar panel company Solyndra? He gave the company more than $5 million that wasn’t his — a “loan” — less than two years before its bankruptcy. Joe “Bugout” Biden pushed for trillions of dollars in “clean energy” spending. I have yet to find anything Biden was involved in during his entire career that wasn’t crooked, but let’s give him the benefit of the doubt. Nevertheless, it produced nothing of use. There were many, many studies, but like boondoggles such as the California high-speed rail system, it was a lot of money borrowed and spent, in return for practically nothing. And it’s not “clean” energy when, as with electric cars, it produces piles of toxic and dangerous dead batteries and other dangerous scrap.

For example, there are solar panels, such as the ones turning great swaths of the world into mirrored wastelands. They last about as long as your asphalt roof does. They wear out. They are inefficient and become more inefficient over time. Then they must be disposed of. And yes, the government has rules for that. As with so many other “clean” energy technologies, it turns out that they’re not clean, don’t produce much energy, and are expensive. (Unless you are the poor elderly woman in New York City this week, who was killed when one blew loose in a windstorm. Her expenses for everything immediately dropped to zero.)

Likewise windmills and all the rest. Billboards are prohibited on many federal highways because it was thought they would spoil the view — which is now, more and more, of miles of huge windmills turning the countryside into a giant real-life Teletubbies set. Do a search on “windmill disasters” to see how it’s all working out. And that’s before we get to their large-scale killing of birds and disruption of life in the ocean.

And all of this is low-efficiency. Anyone notice how much lower your electric bill is because of all these amazing innovations? I didn’t think so. Me, neither.

Rather than expensive gadgets that dribble out electricity, how about a relatively cheap and highly efficient way of reducing your need for the stuff? Something that requires little maintenance, has no moving parts, lasts for many years and is cheap, anyway? That can’t break unless a volcano covers your house in ash. That makes so much sense that the government doesn’t promote it.

If you live where it’s cold on sunny summer days, you might look into thermochromic coatings for your house and roof.

But the more I look into it, the more I realize that when I replace the roof, probably next year, it will be with a white metal one.

And my cold-shower experience will be vindicated.