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Hot Air Savings

Saving energy at home could take 200 years to repay its cost - Times Online

...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 would take about 208 years to pay back.

The RICS data shows that putting in all eight measures, including insulation, condenser boilers and double glazing, would cost £23,547. This would knock only £486 off fuel bills and would take 48 years to recoup.

That's why the Castle is unadorned with turbines and solar panels, but has just had the oil fired heating boosted to give even more gallons of steaming hot water!


TV and all other required equipment is on stand-by ready for a quick start for the rugby in the morning. It is a case of an extra 5 minutes in bed against an increase in global temperature (possibly) of about 0.0000000000000000000000000000001 degree C. I'll take the 5 minutes in bed.

Economic illiteracy. Simply dividing a capital sum by an annual return on that sum to get a payoff period ignores the time value of money. A stream of payments in perpetuity is a form of annuity, and the present value of a perpetual annuity is the payment divided by the discount rate. A generous discount rate of 5% makes a £24 p.a. stream of revenue worth £480, i.e. less than one tenth of the capital outlay. More realistic rates reduce this nugatory sum still further. I note, also, that no account is taken of wear-and-tear and lifetime issues. I don't know what the lifetime of a solar array is, but I can't imagine it's more than 20 years. This drops the present value still further. Twenty four quid a year for 20 years at 5% discount is only about £308.

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