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The elephant in the room with "renewables" is batteries. In order for renewables to be truly as convenient as grid power, there has to be a storage system of s

The elephant in the room with "renewables" is batteries. In order for renewables to be truly as convenient as grid power, there has to be a storage system of some kind at the site of use. Generally that means, in your car, in your home, etc. The environmental cost of disposing of batteries hardly insignificant.

redwall_hp 7y ago
Or low energy yield per square meter required. e.g. solar is like 200W/m^2 (and doesn't run all day, so the watt-hour rating gets kneecapped), wind isn't fantastic either. This won't scale well with anticipated energy needs. It would be a real struggle to cover our current energy needs with wind and solar (with other renewables like hydro and geothermal being geographically limited, subject to environmental issues and more or less already maximized where they can be used)...and we need more. We're heading toward electric cars with batteries that hold 3x what the average household uses in a day (which drain in a few hundred miles), and will need more energy for carbon capture and desalination as time goes on...
- pfdietz 7y ago
  Land area is not a problem with current energy needs. I wish you folks would actually do the arithmetic on this.
manfredo 7y ago
Or just use fission, which is renewable through uranium seaewter extraction.
- dgemm 7y ago
  That is not renewable, it's just a very large source of non-renewable fuel.
  - DennisP 7y ago
    Actually, since uranium in the ocean is at equilibrium, if we take some out then the concentration will go back up as more uranium is dissolved from rocks. Of course it will run out eventually but so will the sun, in a similar amount of time.
  - manfredo 7y ago
    There's an estimated 2 billion years worth of dissolved uranium. Not truly renewable I suppose, but by that metric solar power isn't renewable either. Eventually all the hydrogen in th sun will be fused.
    - pfdietz 7y ago
      You have mangled your data there. That claim is incorrect.
      - manfredo 7y ago
        This estimate says a billion years: https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-seawater-extraction-makes-nuclear-power-completely-renewable/ https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-s...
        pfdietz 7y ago
        Um, no it doesn't. It claims that dissolved U would be replenished faster than we'd u se it (but that claim is wrong, I think); it doesn't say the U that us currently dissolved would last a billion years.
        wahern 7y ago
        FWIW, this might be the primary source everybody is unintentionally quoting, or at least much closer to the primary source: > Although the concentration of uranium is quite low, about 3.3 ppb (parts per billion) in seawater of average oceanic salinity, the amount present in the total volume of the oceans is very great, some 4.5 billion tonnes. Of this, perhaps only that uranium contained in the upper 100 meters or so of the surface well-mixed layer should be considered accessible for recovery, some 160 million tonnes. Practically speaking, the amount contained in the ocean surface layers is unlimited with respect to large scale extraction in the forseeable future. This results from the replenishment by continental weathering and river runoff being much larger than forseeable extraction rates. ... > 1) The surface waters of the oceans comprise a virtually inexhaustible uranium resource of some 160 million tonnes, extractible indefinitely at a rate of a few thousand tonnes per year. Exxon Nuclear Company, "EXTRACTION OF URANIUM FROM SEAWATER: EVALUATION OF URANIUM RESOURCES AND PLANT SITING, VOLUME I", pp 6-7, 9, February 1979, https://www.osti.gov/servlets/purl/6191296 https://www.osti.gov/servlets/purl/6191296 The above quotes are from the executive summary. Page 35 has the money quote: > This represents an influx of about 9000 tonnes annually. Which supports your contention that sea water CANNOT provide an endless supply considering that current annual consumption is ~90,000 tonnes, 10x the replacement rate. EDIT: s/CANNOT NOT/CANNOT/
toomuchtodo 7y ago
https://data.bloomberglp.com/professional/sites/24/Capture2.jpg https://data.bloomberglp.com/professional/sites/24/Capture2.... https://about.bnef.com/blog/behind-scenes-take-lithium-ion-battery-prices/ https://about.bnef.com/blog/behind-scenes-take-lithium-ion-b... "The key determinant of our forecast is the relationship between price and volume. From the observed historical values, we calculate a learning rate of around 18%. This means that for every doubling of cumulative volume, we observe an 18% reduction in price. Based on this observation, and our battery demand forecast, we expect the price of an average battery pack to be around $94/kWh by 2024 and $62/kWh by 2030." TLDR Batteries will work out fine as storage. Recycling batteries is a known materials handling process.
- AnthonyMouse 7y ago
  They're predicted to work out fine. And maybe they will -- which would be great. But even if there is a 75% chance of that happening, we should still be prepared for the alternative if it doesn't. Don't put all your eggs in one basket etc.
  - toomuchtodo 7y ago
    Limited resources require prioritization when allocating resources. Batteries are proven (there are GWs of utility battery storage provisioned and operating as expected), fusion is not.
    - AnthonyMouse 7y ago
      It's hard to argue limited resources when they're talking about spending £200M against the size of the global energy market. Limited resources is an argument for spending 80% on storage and 20% on fusion, not an argument for not even spending <0.1% on fusion.
qubex 7y ago
There are so many energy storage devices besides batteries. Yes, they’re confident for storing electric charge, but (as I mentioned elsewhere) pumping water up into a reservoir when energy is plentiful and using it to drive turbines and generators is another large-scale energy storage system, as is melting salts, as is driving compressors to pressurise large cambers and then drive them in reverse when power dips, as is spinning up flywheels...
- Gibbon1 7y ago
  Completely boring thermal storage schemes give you 40-70% round trip energy return. As long as you can sell the stored power for 1.5 to 2.5 times more than you paid for it then it's economically feasible. Problem with the technology is a) not viable in the current market. b) It's a mind numbingly boring idea. c) There is no 'disruption' potential here. All the companies that can build this at scale are huge established multi-nationals like General Electric.
- steve19 7y ago
  Pumped storage requires very specific geography and how much energy can be stored is very dependant on height differences. It is also only 70-80% efficient. Compressed-air energy storage also requires specific geography. Molten salt is not going to be a great idea in places that have lots of wind, but not a lot of sun (UK in winter for example). To replace strip mined coal burning generators and fracked gas we need a mix of just about everything.
  - dharma1 7y ago
    I agree it's going to be a combination of solutions with energy storage, depending on what you need. Batteries are good for short-term, portable storage. The other solutions you mentioned may be better for long-term, non-portable storage. I also think we can get more mileage out of chemical fuels produced with renewables - ammonia, hydrogen. https://www.greentechmedia.com/articles/read/siemens-ammonia-hydrogen-energy-storage https://www.greentechmedia.com/articles/read/siemens-ammonia... https://www.sciencemag.org/news/2019/03/new-fuel-cell-could-help-fix-renewable-energy-storage-problem https://www.sciencemag.org/news/2019/03/new-fuel-cell-could-...

redwall_hp 7y ago

Or low energy yield per square meter required. e.g. solar is like 200W/m^2 (and doesn't run all day, so the watt-hour rating gets kneecapped), wind isn't fantastic either. This won't scale well with anticipated energy needs. It would be a real struggle to cover our current energy needs with wind and solar (with other renewables like hydro and geothermal being geographically limited, subject to environmental issues and more or less already maximized where they can be used)...and we need more. We're heading toward electric cars with batteries that hold 3x what the average household uses in a day (which drain in a few hundred miles), and will need more energy for carbon capture and desalination as time goes on...

pfdietz 7y ago
Land area is not a problem with current energy needs. I wish you folks would actually do the arithmetic on this.

manfredo 7y ago

Or just use fission, which is renewable through uranium seaewter extraction.

dgemm 7y ago
That is not renewable, it's just a very large source of non-renewable fuel.
- DennisP 7y ago
  Actually, since uranium in the ocean is at equilibrium, if we take some out then the concentration will go back up as more uranium is dissolved from rocks. Of course it will run out eventually but so will the sun, in a similar amount of time.
- manfredo 7y ago
  There's an estimated 2 billion years worth of dissolved uranium. Not truly renewable I suppose, but by that metric solar power isn't renewable either. Eventually all the hydrogen in th sun will be fused.
  - pfdietz 7y ago
    You have mangled your data there. That claim is incorrect.
    - manfredo 7y ago
      This estimate says a billion years: https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-seawater-extraction-makes-nuclear-power-completely-renewable/ https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-s...
      - pfdietz 7y ago
        Um, no it doesn't. It claims that dissolved U would be replenished faster than we'd u se it (but that claim is wrong, I think); it doesn't say the U that us currently dissolved would last a billion years.
        wahern 7y ago
        FWIW, this might be the primary source everybody is unintentionally quoting, or at least much closer to the primary source: > Although the concentration of uranium is quite low, about 3.3 ppb (parts per billion) in seawater of average oceanic salinity, the amount present in the total volume of the oceans is very great, some 4.5 billion tonnes. Of this, perhaps only that uranium contained in the upper 100 meters or so of the surface well-mixed layer should be considered accessible for recovery, some 160 million tonnes. Practically speaking, the amount contained in the ocean surface layers is unlimited with respect to large scale extraction in the forseeable future. This results from the replenishment by continental weathering and river runoff being much larger than forseeable extraction rates. ... > 1) The surface waters of the oceans comprise a virtually inexhaustible uranium resource of some 160 million tonnes, extractible indefinitely at a rate of a few thousand tonnes per year. Exxon Nuclear Company, "EXTRACTION OF URANIUM FROM SEAWATER: EVALUATION OF URANIUM RESOURCES AND PLANT SITING, VOLUME I", pp 6-7, 9, February 1979, https://www.osti.gov/servlets/purl/6191296 https://www.osti.gov/servlets/purl/6191296 The above quotes are from the executive summary. Page 35 has the money quote: > This represents an influx of about 9000 tonnes annually. Which supports your contention that sea water CANNOT provide an endless supply considering that current annual consumption is ~90,000 tonnes, 10x the replacement rate. EDIT: s/CANNOT NOT/CANNOT/

toomuchtodo 7y ago

https://data.bloomberglp.com/professional/sites/24/Capture2.jpg https://data.bloomberglp.com/professional/sites/24/Capture2.... https://about.bnef.com/blog/behind-scenes-take-lithium-ion-battery-prices/ https://about.bnef.com/blog/behind-scenes-take-lithium-ion-b... "The key determinant of our forecast is the relationship between price and volume. From the observed historical values, we calculate a learning rate of around 18%. This means that for every doubling of cumulative volume, we observe an 18% reduction in price. Based on this observation, and our battery demand forecast, we expect the price of an average battery pack to be around $94/kWh by 2024 and $62/kWh by 2030." TLDR Batteries will work out fine as storage. Recycling batteries is a known materials handling process.

AnthonyMouse 7y ago
They're predicted to work out fine. And maybe they will -- which would be great. But even if there is a 75% chance of that happening, we should still be prepared for the alternative if it doesn't. Don't put all your eggs in one basket etc.
- toomuchtodo 7y ago
  Limited resources require prioritization when allocating resources. Batteries are proven (there are GWs of utility battery storage provisioned and operating as expected), fusion is not.
  - AnthonyMouse 7y ago
    It's hard to argue limited resources when they're talking about spending £200M against the size of the global energy market. Limited resources is an argument for spending 80% on storage and 20% on fusion, not an argument for not even spending <0.1% on fusion.

qubex 7y ago

There are so many energy storage devices besides batteries. Yes, they’re confident for storing electric charge, but (as I mentioned elsewhere) pumping water up into a reservoir when energy is plentiful and using it to drive turbines and generators is another large-scale energy storage system, as is melting salts, as is driving compressors to pressurise large cambers and then drive them in reverse when power dips, as is spinning up flywheels...

Gibbon1 7y ago
Completely boring thermal storage schemes give you 40-70% round trip energy return. As long as you can sell the stored power for 1.5 to 2.5 times more than you paid for it then it's economically feasible. Problem with the technology is a) not viable in the current market. b) It's a mind numbingly boring idea. c) There is no 'disruption' potential here. All the companies that can build this at scale are huge established multi-nationals like General Electric.
steve19 7y ago
Pumped storage requires very specific geography and how much energy can be stored is very dependant on height differences. It is also only 70-80% efficient. Compressed-air energy storage also requires specific geography. Molten salt is not going to be a great idea in places that have lots of wind, but not a lot of sun (UK in winter for example). To replace strip mined coal burning generators and fracked gas we need a mix of just about everything.
- dharma1 7y ago
  I agree it's going to be a combination of solutions with energy storage, depending on what you need. Batteries are good for short-term, portable storage. The other solutions you mentioned may be better for long-term, non-portable storage. I also think we can get more mileage out of chemical fuels produced with renewables - ammonia, hydrogen. https://www.greentechmedia.com/articles/read/siemens-ammonia-hydrogen-energy-storage https://www.greentechmedia.com/articles/read/siemens-ammonia... https://www.sciencemag.org/news/2019/03/new-fuel-cell-could-help-fix-renewable-energy-storage-problem https://www.sciencemag.org/news/2019/03/new-fuel-cell-could-...