Cool non-savings
Posted by aogFriday, 05 June 2009 at 14:22 TrackBack Ping URL

Via Brothers Judd is an article on Secretary of Energy Chu’s call to paint roofs white to which Judd responds

Sure, it wouldn’t do bupkus for warming … but if it cuts consumers’ bills why not do it?

I would be very surprised if this cut costs for consumers. Any one suggesting this has very likely not actually priced what it costs to paint a roof. I would bet money that painting your roof white is a money loser because you don’t recoup the painting cost before you have to paint it again. And what does all that paint do for the environment?

Semi-off-topic — we’re looking at new air cooling systems for our house. The cost is something on the order of 5-10 times our annual energy costs to cool the house. So even if it made cooling free, it would be the better part of a decade before we had a net economic benefit. At the 20% cost savings claimed, that’s 50-100 years. That’s even with manufacturer rebates and government subsidies tax credits. It frankly just doesn’t make economic sense, we’re only looking at it because the current units are old and may fail at any time, and just do not have the cooling power needed for the house.

UPDATE: It’s even worse than I wrote here. Suppose it costs $5000 for the cooling units and $1000/year for cooling (these are ballpark numbers for my house). If the upgrade saves 20%, that’s $200/year. But 10 year T-bills have popped up to 3.8%, which means I could get $190/year by buying $5000 worth of them. So I would be netting $10/year, which means the payoff time is five hundred years. Another bump in T-bill rates and I am better off buying them and using that to pay the cooling costs. Double the energy savings and it is still a multi-century payoff.

Comments — Formatting by Textile
erp Friday, 05 June 2009 at 15:37

Are all roofs are even paintable?

I hope you let us know what you decide on a new A/C — our Trane is 20 years old and probably won’t last forever.

Harry Eagar Friday, 05 June 2009 at 16:18

If you paint the roofs white, then you cannot grow grass on them and have green roofs,

I look forward to a Texas cage match between the environmental white roofers and green roofers.

Chu didn’t just say roofs, either. He wants to make roadways reflective. I suspect that would not just cost you money but get you killed.

The community college has announced a new science building, which will have a green roof. Within minutes of my story about it, I got an email from an environmental architect wanting to know details about the green roof. He was disappointed to learn that our county, unlike Portland, does not subsidize green roofs by $5/sq ft.

I pointed out to him that for a 2,000 sq ft roof on the $26,000,000 building, the $10,000 subsidy wouldn’t mean much. Haven’t heard back from him.

Maybe instead of an A/C you could grow grass on your roof. Then you could keep goats and sell the milk.

This makes at least the third time that Chu has said something inane (even if you were to accept his AGW alarmism). I wonder (mildly) what’s up with him.

Bret Friday, 05 June 2009 at 16:26

If white roofs save cooling costs, wouldn’t they also increase heating costs in the winter?

Annoying Old Guy Friday, 05 June 2009 at 18:09

I actually have a friend who has a green roof. He built a new house and put it mostly underground (I forget the official term for that) to minimize heating and cooling costs (the dual of a geo-thermal system). Because of this, his lawn goes up and over his house.

Hey Skipper Friday, 05 June 2009 at 20:26

If white roofs save cooling costs, wouldn’t they also increase heating costs in the winter?

Where I live, they are white all winter (and part of fall and spring, too) anyway.

Of course, excess cooling costs are not a, ummm, burning issue up here.

erp Friday, 05 June 2009 at 22:06

aog, I remember reading in Willa Cather’s “My Antonia” that because of a dearth of building materials, original settlers often built their homes underground.

It was one of the reasons the book had me in tears. I wonder what those folks would think about your friend building his house underground in 2009.

Does he have sky lights for additional illumination?

Barry Meislin Sunday, 07 June 2009 at 06:56

Ah, sod it.

Annoying Old Guy Monday, 08 June 2009 at 07:43


No, I don’t think it has sky lights. I do find it an interesting example of how the tribulations of the past become the fashion of the future (just look at all the “starvation foods” that are now consumed as luxury items.

AVeryRoughRoadAhead Monday, 08 June 2009 at 23:12
Suppose it costs … $1000/year for cooling…
But 10 year T-bills have popped up to 3.8%, which means I could get $190/year by buying $5000 worth of them.

A penetrating analysis, but static. All of the variables are going to change.

  • Energy costs for heating/cooling aren’t going to stay at such low levels. In real terms, it may well cost you three or four times as much in a decade, as the costs of oil, natural gas, coal and uranium inevitably rise.
  • If you locked in 3.8% returns for a full ten years, you’d soon regret it. Inflation over the next ten years could easily hit double-digits - the G7 gov’ts are planning on borrowing an average of another 20% of their current national debts over the next two years, and then pumping their economies with the money. That can’t be done without leading to both higher interest rates and higher inflation. Plus we’ve got the Boomer retirement entitlements to fund, and that ain’t gonna happen unless the nominal dollars that they’ve been promised have an intrinsic value only slighty north of toilet paper.
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