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| the dark side of cobalt |
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| peter-h:
Electric cars will reach a plateau before long. It is already starting in some areas. The problem is that > 50% (the actual figure has certainly been well researched but seems unpublished) of the population in the developed world has no charging opportunities. Electric aircraft projects are being abandoned very fast. They were wonderful for "green" column-inches on social media, and collecting EU R&D grants ;) Ground sourced heat pumps are indeed great (I have been around that business since the 1970s) but for most people impossible, or very expensive with a few tens of k for a borehole. It is easy only if you have a fairly large field, say 1-3 acres and then you only need a ~1m deep trench for the pipe. Or a lake, or a stream which is always running. Air source heat pumps are crap; the COP is largely fiction due to evaporator icing. I am rather very familiar with this... The appliance also rots away in not too many years. |
| NiHaoMike:
It seems like what would really solve a large part of the energy problem is some sort of heat transportation system interconnecting countries in southern and northern hemispheres. It's technically feasible, but nobody has found a way to make it economically feasible yet. |
| tom66:
--- Quote from: NiHaoMike on July 16, 2023, 01:12:46 pm ---It seems like what would really solve a large part of the energy problem is some sort of heat transportation system interconnecting countries in southern and northern hemispheres. It's technically feasible, but nobody has found a way to make it economically feasible yet. --- End quote --- Why not just transport electricity? China has a 3,200km ultra HVDC transmission line (+/-1.1MV) built by ABB, it transmits up to 12GW. Efficiency is in excess of 90%. Going up to +/-1.5MV UHVDC could allow transmission beyond 5,000km with similar efficiency. |
| Marco:
--- Quote from: Siwastaja on July 16, 2023, 09:24:38 am ---Ground source heatpumping is a big deal because it combines annual storage with renewable energy source (sunlight) harvesting in one simple package. --- End quote --- As always, I'm disappointed governments aren't trying to put in district heating with street level ground source heat pumps ... it makes far more sense than forcing individuals to install air source heatpumps which can't feed old radiators. Trenchless techniques have changed the solution space massively from classical district heating solutions. Hot/warm/chilled water should be an utility. |
| NiHaoMike:
--- Quote from: tom66 on July 16, 2023, 03:35:43 pm ---Why not just transport electricity? China has a 3,200km ultra HVDC transmission line (+/-1.1MV) built by ABB, it transmits up to 12GW. Efficiency is in excess of 90%. Going up to +/-1.5MV UHVDC could allow transmission beyond 5,000km with similar efficiency. --- End quote --- The temperature difference between the hot and cold areas is an energy source that could theoretically be exploited. Probably not enough to make the whole system a net generator, but it could make the effective efficiency very high. |
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