[ExI] pentagon wants orbiting solar power stations

[Eugen Leitl]

On Sat, Oct 13, 2007 at 04:41:12PM +0100, BillK wrote:

> Article in today's Times newspaper:
> <http://www.timesonline.co.uk/tol/news/uk/science/article2648540.ece>
> 
> Saving energy at home could take 200 years to repay its cost.

Bulllllllshit. Saving is all about the costs.

http://www.passivhaustagung.de/Passivhaus_D/Graue_Energie_und_Passivhaus_2007.htm

This is not just money, this is energy ROI over life time.
 
> The Energy Performance Certificates which are now required with all
> Home Information Packs for houses with three or more bedrooms list
> eight measures to secure a high rating of A or B against a poor rating
> of F or G.
> 
> But the study from the Royal Institute of Chartered Surveyors shows
> that some of the measures, such as solar panels to heat water, would
> cost £5,000 to install but reduce average bills by only £24 a year and

How about 60% less heating costs, every year?

> would take about 208 years to pay back.

How about after 8 years, worst case?

> Some of the comments on the article say that their cost figures seem
> high. I suspect this is because they have assumed professional
> installation not DIY.

8 years is for professional installation. DIY is probably 3-5 years.
 
> Cavity wall insulation seems to be the only worthwhile enhancement to

Insulation is the investment with highest ROI. Solar thermal is the next
item. Somewhen much later is lighting.

http://www.economist.com/surveys/displaystory.cfm?story_id=9217972

Irrational incandescence indeed.

> pay contractors to install.  If you are fit, then DIY loft insulation
> is also worth doing.
> 
> Legislation in the UK stops DIY work on gas and electrical installations.

Sounds like a good thing. Certainly not a show-stopper.
 
> So solar power has to have a substantial cost reduction before it
> becomes practical. I keep reading articles predicting cost

If I drive around the neighborhood, I would say that solar has become
practical a decade ago, at least. Did I mention that the place I rent
out is heated by geothermal, Kalina cycle?

> breakthroughs in solar cells, so hopefully price reductions will be
> coming soon.

PV is only about electricity. Crossover outside of niches (it has already
occured in temporal and spatial niches) there should happen within the next
decade, depending on development of fossil costs and whether the market
can meet demand, so that prices don't stay up.

-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
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