gadget Posted May 11, 2013 Share Posted May 11, 2013 Thought some people might be interested in this article from the economist: http://www.economist.com/news/americas/21577073-having-spent-heavily-make-worlds-third-biggest-hydroelectric-project-greener-brazil Link to comment Share on other sites More sharing options...
Kurt Barlow Posted May 12, 2013 Share Posted May 12, 2013 Thought some people might be interested in this article from the economist: http://www.economist.com/news/americas/21577073-having-spent-heavily-make-worlds-third-biggest-hydroelectric-project-greener-brazil Interesting article - thanks for posting. The article also shows the dangers of being too over reliant on one source of power. In Brazils case Hydro which is vulnerable to droughts. It looks like a diverse approach using wind and bagasse (from sugar cane) is the way forward. Wind coincidentially is strongest in the dry season so works well with solar. Link to comment Share on other sites More sharing options...
gadget Posted May 12, 2013 Author Share Posted May 12, 2013 Interesting article - thanks for posting. The article also shows the dangers of being too over reliant on one source of power. In Brazils case Hydro which is vulnerable to droughts. It looks like a diverse approach using wind and bagasse (from sugar cane) is the way forward. Wind coincidentially is strongest in the dry season so works well with solar. Really quite eye-opening how much of a renewables super-power Brazil is. Link to comment Share on other sites More sharing options...
Executive Sadman Posted May 12, 2013 Share Posted May 12, 2013 Yes, HEP doesnt seem to be favoured much by the political class lately. I recall Tasmania was once something like 100% HEP covered, now its well below that and some stations have been mothballed. Even our antartic whaling outpost of south georgia once had a HEP plant, now it relies on diesel generators and diesel being shipped in. Link to comment Share on other sites More sharing options...
fluffy666 Posted May 13, 2013 Share Posted May 13, 2013 Really quite eye-opening how much of a renewables super-power Brazil is. Dam-based hydroelectricity is about the cheapest form of electricity there is, IIRC. Only problem being that you need the right geography - you need a bit river in a big valley. Link to comment Share on other sites More sharing options...
Guest eight Posted May 13, 2013 Share Posted May 13, 2013 Dam-based hydroelectricity is about the cheapest form of electricity there is, IIRC. Cheaper than tapping next door's mains? Link to comment Share on other sites More sharing options...
Riedquat Posted May 13, 2013 Share Posted May 13, 2013 Dam-based hydroelectricity is about the cheapest form of electricity there is, IIRC. Only problem being that you need the right geography - you need a bit river in a big valley. I seem to recall that Brazil has a rather big river flowing through a lot of it... (not so sure about how much of a valley it's in though) Link to comment Share on other sites More sharing options...
swissy_fit Posted May 13, 2013 Share Posted May 13, 2013 I seem to recall that Brazil has a rather big river flowing through a lot of it... (not so sure about how much of a valley it's in though) They get a lot of hydro energy from a dam in Paraguay at a cheap rate negotiated years and years ago. Link to comment Share on other sites More sharing options...
Kurt Barlow Posted May 13, 2013 Share Posted May 13, 2013 I seem to recall that Brazil has a rather big river flowing through a lot of it... (not so sure about how much of a valley it's in though) Its the absence of much of a head of water on the Amazon (main body) that I suspect has dissuaded the Brazilian PTB to dam it. Also the amazon itself is a long way from the big cities so the transmission costs would be very high. A simple formula for approximating electric power production at a hydroelectric plant is: P = \rho hrgk , where P is Power in watts, \rho is the density of water (~1000 kg/m3), h is height in meters, (which explains why no one has bothered to dam the Great Ouse, Thames etc (other than micro schemes) r is flow rate in cubic meters per second, g is acceleration due to gravity of 9.8 m/s2, k is a coefficient of efficiency ranging from 0 to 1. Efficiency is often higher (that is, closer to 1) with larger and more modern turbines. Link to comment Share on other sites More sharing options...
motch Posted May 13, 2013 Share Posted May 13, 2013 Its the absence of much of a head of water on the Amazon (main body) that I suspect has dissuaded the Brazilian PTB to dam it. Also the amazon itself is a long way from the big cities so the transmission costs would be very high. A simple formula for approximating electric power production at a hydroelectric plant is: P = \rho hrgk , where P is Power in watts, \rho is the density of water (~1000 kg/m3), h is height in meters, (which explains why no one has bothered to dam the Great Ouse, Thames etc (other than micro schemes) r is flow rate in cubic meters per second, g is acceleration due to gravity of 9.8 m/s2, k is a coefficient of efficiency ranging from 0 to 1. Efficiency is often higher (that is, closer to 1) with larger and more modern turbines. on a similar subject, how possible/economical would it be to have huge battery store ships take energy from decent hydro-electric areas (eg scandanavian countries) and transport them to cities around the world that need it ? I'd guess not very economical, but who knows. Link to comment Share on other sites More sharing options...
swissy_fit Posted May 13, 2013 Share Posted May 13, 2013 on a similar subject, how possible/economical would it be to have huge battery store ships take energy from decent hydro-electric areas (eg scandanavian countries) and transport them to cities around the world that need it ? I'd guess not very economical, but who knows. Don't think suitable battery tech exists - cheaper to put in some interconnectors, this is in progress I think. Link to comment Share on other sites More sharing options...
Kurt Barlow Posted May 13, 2013 Share Posted May 13, 2013 on a similar subject, how possible/economical would it be to have huge battery store ships take energy from decent hydro-electric areas (eg scandanavian countries) and transport them to cities around the world that need it ? I'd guess not very economical, but who knows. In the case of Scandinavia or Iceland HVDC interconnectors is the answer. However there are remote hydro resources where HVDC is too far. Example would be the the Inga falls on the Congo river with a potential of 40GW. One way of exporting that energy would be to make ammonia which can then be used in fertiisers, flue gas desulphurisation, or even fuel as diesel engines only need minor modification. Also there is a tidal site in the Sea of Okhotsk (Russian Far East) with a potential of about 80GW. Very remote so electricity could be used to make Ammonia and ship to China, Japan etc. Link to comment Share on other sites More sharing options...
Riedquat Posted May 13, 2013 Share Posted May 13, 2013 on a similar subject, how possible/economical would it be to have huge battery store ships take energy from decent hydro-electric areas (eg scandanavian countries) and transport them to cities around the world that need it ? I'd guess not very economical, but who knows. Very uneconomical I would've thought. The energy density of batteries is really pretty lousy. Shipping energy about only makes economic sense when it's in a much better energy density medium like oil. Link to comment Share on other sites More sharing options...
gadget Posted May 13, 2013 Author Share Posted May 13, 2013 Dam-based hydroelectricity is about the cheapest form of electricity there is, IIRC. Only problem being that you need the right geography - you need a bit river in a big valley. That's a bit of a blanket statement. From the article wind is coming out cheaper than recent hydro projects: Recent windpower auctions, with hundreds of private-sector bidders, produced winning bids of 90-100 reais per megawatt-hour (MWh), a price that is hard to beat. Belo Monte was given an initial budget of 16 billion reais, which had risen to 19 billion reais by the time of the auction. Norte Energia’s winning bid for Belo Monte offered a price of 77.97 reais/MWh. Since then, its budget has risen by a third. Link to comment Share on other sites More sharing options...
Kurt Barlow Posted May 14, 2013 Share Posted May 14, 2013 This would be a great scheme and provide plenty of work for Egyptians in the construction phase plus lots of additional benefits including increased rainfall in an arid area. When Egypt was a net oil exporter this sort of scheme would have been a good investment for that revenue stream. http://mragheb.com/NPRE%20498ES%20Energy%20Storage%20Systems/Pumped%20Storage%20Qattara%20Depression%20Solar%20Hydroelectric%20Power%20Generation.pdf Politics gets in the way of this which could provide a large chunk of Israels and Jordans electrical needs http://deadseapower.com/ Both would be useful additions to the proposed Desertec/ Supergrid especially as they can be built as peaking plant with pumped storage. Additionally no dangers of a drought affecting output. Link to comment Share on other sites More sharing options...
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