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Downshifting: Rainwater harvesting and hydroelectric
Hello, I'm new to this forum, long time peeper though. I'm building at the moment and am considering rainwater harvesting to be collected in an underground tank and then pumped back upstairs to a tank serving cisterns and washing machine. Could some form of small hydroelect generator be connected inline as underground tank fills and it's output sent to the smartmeter to offset the cost of pumping it upstairs?
1st bit sounds fine - although I'd go for the easy stuff like insulation and draught-proofing before rainwater harvesting.
The hydroelectric generator bit doesn't seem very viable though:
The amount of energy you could gather as the rainwater falls from the gutter to the tank would be tiny. i.e. 1000L of water falling 10m would give you a maximum of 0.03kwh of energy (or 0.3 pence of electricity).
May be a bit late as your already building but could you not have designed in some water storage higher than the cistern but lower than the gutter. Gravity could have done its work then.
you could put in a header tank big enough for a couple of loads in the washing machine and/or the cistern and use a hand pump to get the water there. Very green and good fitness too
in these times of austerity maybe a personal energy review would lead you to be able to increase your physical output whilst reducing your nutritional input
Several states in India, including Bangalore have made rainwater harvesting compulsary for many new building and existing ones over a certain size, in an effort to address the water shortage problem. It is a planning permission requirement. I can see it happening here too.