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Post by eclipse on Jul 9, 2013 18:46:29 GMT 9.5
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Post by quokka on Jul 9, 2013 21:06:18 GMT 9.5
Promises are easy. Delivering them not so much. For example Denmark: www.iea.org/stats/pdf_graphs/DKTPES.pdfNotice how little wind contributes to primary energy supply. Could (and should) biofuels/biomass expand sufficiently? |
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Post by sod on Jul 10, 2013 5:48:34 GMT 9.5
Promises are easy. Delivering them not so much. For example Denmark: www.iea.org/stats/pdf_graphs/DKTPES.pdfNotice how little wind contributes to primary energy supply. Could (and should) biofuels/biomass expand sufficiently? your comparison (electric wind power to total primary energy supply) is a false one. electricity should NOT be used to heat anything, until we are approaching extremely high levels of alternative power. To give a similar example: Nuclear is a bad technology, as there is no nuclear reactor in my car. Denmark has nearly doubled its wind power output since 2009, by the way: en.wikipedia.org/wiki/Wind_power_in_Denmark |
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Post by David B. Benson on Jul 10, 2013 7:20:08 GMT 9.5
Get back to me when Scotland is actually 100% renewables, never depending upon reliable sources in England for backup.
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Post by edireland on Jul 10, 2013 8:38:10 GMT 9.5
Denmark's total wind energy supply is irrelevant, since it has massive energy transfers across its borders to Norway and Germany both of which are reliant on things that are not non-hydro renewables.
It essentially cheats.
Cut all the power lines in and out of Denmark and see how well it does.
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Post by anonposter on Jul 10, 2013 12:19:07 GMT 9.5
electricity should NOT be used to heat anything, until we are approaching extremely high levels of alternative power. Then what should we use for heating? |
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Post by QuarkingMad on Jul 15, 2013 14:51:35 GMT 9.5
electricity should NOT be used to heat anything, until we are approaching extremely high levels of alternative power. Then what should we use for heating? Biomass. Chop wood and put it in a furnace. Apparently Biomass is the new black. |
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Post by eclipse on Jul 15, 2013 15:33:20 GMT 9.5
Or design homes to be more like Earthships and be self-heating and self-cooling. Or just use reverse cycle air conditioning from nuclear power. (And solar PV for the wealthy can take some 'gold plating' off the grid in those hottest peak demand hours of the year).
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Post by anonposter on Jul 15, 2013 17:42:34 GMT 9.5
Biomass. Chop wood and put it in a furnace. Apparently Biomass is the new black. Thought so, personally I'd rather see wood heating banned for environmental reasons (though maybe we just ban new wood heaters). Or design homes to be more like Earthships and be self-heating and self-cooling. Might work for new construction, but there are a lot of old houses out there (more insulation and new double glazed windows could help but there's still a limit to what you can do with old structures). Also some people may think the energy efficient designs compromise something they value. Or just use reverse cycle air conditioning from nuclear power. That's what I'd do, I'd also encourage ground source heat pumps instead of air source. (And solar PV for the wealthy can take some 'gold plating' off the grid in those hottest peak demand hours of the year). Haven't we already established that that won't work? |
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Post by edireland on Jul 15, 2013 20:43:41 GMT 9.5
Ground Source Heat Pumps have serious problems in high density areas like most of the UK.
During the winter they will likely freeze the ground solid.
Meanwhile direct cycle air-to-air heat pumps get high COPs due to low outlet temperatures and are an awful lot cheaper.
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Post by anonposter on Jul 15, 2013 22:13:48 GMT 9.5
Ground source heat pumps aren't going to be viable for apartment blocks (unless you use ocean water which I understand has been done on a large scale) but in most cases would be the best technology for low density.
Air source heat pumps will in most cases have a temperature further away from the desired one than ground source so will get lower COP (though still quite good).
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Post by edireland on Jul 15, 2013 22:46:02 GMT 9.5
I don't just mean apartment blocks, I am referring to built up low rise areas composed of detached and semi detached houses.
If you freeze the ground bad things happen, and ground source pumps tend to have far high pricetags than air source systems, and the latter tend to be easier to repair. (No hunting for a buried leak in a ground loop).
Air to Air pumps can supposedly get COPs of 5.
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