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I'm stating a simple concept, which is that if you put some wind and solar into a heavily-fossil powered grid, the first 30% wind and solar are easy, and the la

I'm stating a simple concept, which is that if you put some wind and solar into a heavily-fossil powered grid, the first 30% wind and solar are easy, and the last 30% are harder. But if you do 100% wind and solar, then you have to start spending money on things other than generators. The fraction of cost that is wind/solar generators vs. e.g. energy storage systems, transmission, recycling, etc. shifts from 1 to ~0 at scale.

pfdietz 4y ago
If you look at the minimum cost of providing synthetic baseload in a 100% renewable scenario, the renewable inputs can be > 50% of the cost (the other parts being various kinds of storage). This is geographically variable, though.
- Manuel_D 4y ago
  > the other parts being various kinds of storage This is handwaving away the most difficult part of of a 100% renewable grid.
  - ncmncm 4y ago
    By which you mean, of course, the least difficult part, and the part that is needed only after all the hard parts, the ones that actually produce energy in useful form, have been built out.
    - Manuel_D 4y ago
      No, energy storage is a far more challenging task than generating it. To put this in perspective, the world uses 60TWh of energy per day. Most energy storage projects are in the hundreds of megawatt hour range, a few in the gigawatts. Estimated for a 100% renewable grid depends on the solar to wind ratio and degrees of overproduction, but they usually fall in the range of 12-24 hours for a 0 carbon grid. And that figure of 60 TWh is only going to grow as underdeveloped countries become more wealthy and want A/C and other amenities. This is a colossal amount of storage, far outside the bounds of existing storage methods. Hence why plans for a renewable grid assume untested mechanisms like power to gas or compressed air will just scale to near-infinity.
      - ncmncm 4y ago
        In fact energy storage is a trivial matter of high-school-level physics. Most existing storage, taking advantage of existing hydro-power dams, uses excess energy to force water up to the reservoir, which energy is later extracted by letting it flow out through a turbine. New pumped-hydro systems built just for storage will be radically cheaper than existing dams, and be practical in hundreds of times as many places: you just need a hilltop no one is using, and water to pump up to it. The reservoir may be much cheaper than a hydro power dam because it does not need to contain high pressure; an earthen dike suffices. There are numerous other, equally simple methods, for places without enough hills or water. Synthetic fuels like hydrogen and ammonia are an attractive choice because tankage is cheap, and they are transportable and have myriad industrial uses, so after your tankage is full you can sell all further production. Of course one only builds storage after there is excess energy to put in it. We will need a lot of it, in time, but it is all just construction and mechanics: ordinary civil engineering. (If you have to lie about the practicality of storage in order to promote nukes, what does that really tell us about your nukes?)
        Manuel_D 4y ago
        Fusion is trivial high school level physics, too. We all learn about the physics that goes on in the sun's core. You're right that hydroelectric offers lots of storage potential. But it's geographically limited. Great for countries like Norway that have lots of it. But countries that don't can't just summon dam-able mountain valleys. You need more than just a hilltop to build pumped hydro. You need a hilltop, with access to a water source. It also needs to be close to a transportation network otherwise construction costs will be prohibitively expensive. Pumped hydro plants do indeed cost a lot: the biggest one in the US in Bath County cost $4 billion dollars for a capacity of 24 GWh. Furthermore, it will get more expensive as it scales up: as the most accessible sites are developed, subsequent facilities have to be built in more and more suboptimal sites. > The reservoir may be much cheaper than a hydro power dam because it does not need to contain high pressure; an earthen dike suffices This makes absolutely no sense. I needs high pressure to generate electricity. Low pressure would mean there's hardly any potential energy to tap. If you're suggesting we have a tunnel leading out from under the reservoir, then those have to be built in exactly the right geography where there's an alpine lake with a height difference. > There are numerous other, equally simple methods, for places without enough hills or water. Yet, despite these methods purported simplicity you didn't actually specify them (Edit: you added a couple in an edit after I typed my reply). Because then you'd have to defend their viability. Since you edited in hydrogen and ammonia: * Power to hydrogen: electrolysis of water remains expensive, hence why most hydrogen is built with steam reformation. It's not just the electricity costs, but also maintaining the electrodes that perform the hydrolysis. * Power to Ammonia: this needs a source of hydrogen, so it shares all of the above's issues. Ammonia is really just a storage mechanism for hydrogen, actually producing usable energy from ammonia is done by releasing the hydrogen from the ammonia and then running it through a fuel cell. You're the one being overly optimistic about the practicality of storage. We've had excess production during peak renewable generation for close to a decade now. The excuse that we won't build storage until there's an excess of electricity isn't valid. Places like Hawaii and California already are saturating the energy market, but the storage is systems you propose aren't being built because they aren't feasible. Intermittent sources are fine to chip away at fossil fuel use, or in places with widespread hydroelectric power. But we can't kid ourselves into thinking that storage will make it feasible every. Grid scale energy storage should be approached like fusion: maybe it'll be invented and change the energy landscape. But it's foolish to treat that possibility as a given.
  - formvoltron 4y ago
    $140 / kwh of lifepo4 storage... TODAY. 6000 cycles this is 2.3 cents per kwh for storage. Where is the handwaving?
    - Manuel_D 4y ago
      Cost today? Or last year? Lithium prices have increased over 400% last year. If demand increases suddenly, price will increase as well. The demand for batteries has led to drastic increases in the cost of input materials: https://www.canarymedia.com/articles/batteries/chart-lithium-prices-are-through-the-roof-this-year https://www.canarymedia.com/articles/batteries/chart-lithium... For this reason, the costs of recent battery storage has risen considerably. Recent storage projects ended up paying $567/Kwh : https://www.utilitydive.com/news/new-york-battery-storage-costs-rise-interconnection-queue-12-gw/621954/ https://www.utilitydive.com/news/new-york-battery-storage-co... This is the scaling problem: if you try to deploy batteries at scales relevant to the energy grid you outstrip the supply of inputs. In order to keep up with demand, extraction industries have to tap more and more inaccessible reserves thus driving up costs. Remember, global electricity usage is 60 TWh per day. And that's just electricity, total energy use is about twice that at 120 TWh per day. Even just 12 hours of storage is hundreds of times the annual battery output - most of which isn't going to grid storage but rather electric vehicles.

pfdietz 4y ago

If you look at the minimum cost of providing synthetic baseload in a 100% renewable scenario, the renewable inputs can be > 50% of the cost (the other parts being various kinds of storage). This is geographically variable, though.

Manuel_D 4y ago
> the other parts being various kinds of storage This is handwaving away the most difficult part of of a 100% renewable grid.
- ncmncm 4y ago
  By which you mean, of course, the least difficult part, and the part that is needed only after all the hard parts, the ones that actually produce energy in useful form, have been built out.
  - Manuel_D 4y ago
    No, energy storage is a far more challenging task than generating it. To put this in perspective, the world uses 60TWh of energy per day. Most energy storage projects are in the hundreds of megawatt hour range, a few in the gigawatts. Estimated for a 100% renewable grid depends on the solar to wind ratio and degrees of overproduction, but they usually fall in the range of 12-24 hours for a 0 carbon grid. And that figure of 60 TWh is only going to grow as underdeveloped countries become more wealthy and want A/C and other amenities. This is a colossal amount of storage, far outside the bounds of existing storage methods. Hence why plans for a renewable grid assume untested mechanisms like power to gas or compressed air will just scale to near-infinity.
    - ncmncm 4y ago
      In fact energy storage is a trivial matter of high-school-level physics. Most existing storage, taking advantage of existing hydro-power dams, uses excess energy to force water up to the reservoir, which energy is later extracted by letting it flow out through a turbine. New pumped-hydro systems built just for storage will be radically cheaper than existing dams, and be practical in hundreds of times as many places: you just need a hilltop no one is using, and water to pump up to it. The reservoir may be much cheaper than a hydro power dam because it does not need to contain high pressure; an earthen dike suffices. There are numerous other, equally simple methods, for places without enough hills or water. Synthetic fuels like hydrogen and ammonia are an attractive choice because tankage is cheap, and they are transportable and have myriad industrial uses, so after your tankage is full you can sell all further production. Of course one only builds storage after there is excess energy to put in it. We will need a lot of it, in time, but it is all just construction and mechanics: ordinary civil engineering. (If you have to lie about the practicality of storage in order to promote nukes, what does that really tell us about your nukes?)
      - Manuel_D 4y ago
        Fusion is trivial high school level physics, too. We all learn about the physics that goes on in the sun's core. You're right that hydroelectric offers lots of storage potential. But it's geographically limited. Great for countries like Norway that have lots of it. But countries that don't can't just summon dam-able mountain valleys. You need more than just a hilltop to build pumped hydro. You need a hilltop, with access to a water source. It also needs to be close to a transportation network otherwise construction costs will be prohibitively expensive. Pumped hydro plants do indeed cost a lot: the biggest one in the US in Bath County cost $4 billion dollars for a capacity of 24 GWh. Furthermore, it will get more expensive as it scales up: as the most accessible sites are developed, subsequent facilities have to be built in more and more suboptimal sites. > The reservoir may be much cheaper than a hydro power dam because it does not need to contain high pressure; an earthen dike suffices This makes absolutely no sense. I needs high pressure to generate electricity. Low pressure would mean there's hardly any potential energy to tap. If you're suggesting we have a tunnel leading out from under the reservoir, then those have to be built in exactly the right geography where there's an alpine lake with a height difference. > There are numerous other, equally simple methods, for places without enough hills or water. Yet, despite these methods purported simplicity you didn't actually specify them (Edit: you added a couple in an edit after I typed my reply). Because then you'd have to defend their viability. Since you edited in hydrogen and ammonia: * Power to hydrogen: electrolysis of water remains expensive, hence why most hydrogen is built with steam reformation. It's not just the electricity costs, but also maintaining the electrodes that perform the hydrolysis. * Power to Ammonia: this needs a source of hydrogen, so it shares all of the above's issues. Ammonia is really just a storage mechanism for hydrogen, actually producing usable energy from ammonia is done by releasing the hydrogen from the ammonia and then running it through a fuel cell. You're the one being overly optimistic about the practicality of storage. We've had excess production during peak renewable generation for close to a decade now. The excuse that we won't build storage until there's an excess of electricity isn't valid. Places like Hawaii and California already are saturating the energy market, but the storage is systems you propose aren't being built because they aren't feasible. Intermittent sources are fine to chip away at fossil fuel use, or in places with widespread hydroelectric power. But we can't kid ourselves into thinking that storage will make it feasible every. Grid scale energy storage should be approached like fusion: maybe it'll be invented and change the energy landscape. But it's foolish to treat that possibility as a given.
- formvoltron 4y ago
  $140 / kwh of lifepo4 storage... TODAY. 6000 cycles this is 2.3 cents per kwh for storage. Where is the handwaving?
  - Manuel_D 4y ago
    Cost today? Or last year? Lithium prices have increased over 400% last year. If demand increases suddenly, price will increase as well. The demand for batteries has led to drastic increases in the cost of input materials: https://www.canarymedia.com/articles/batteries/chart-lithium-prices-are-through-the-roof-this-year https://www.canarymedia.com/articles/batteries/chart-lithium... For this reason, the costs of recent battery storage has risen considerably. Recent storage projects ended up paying $567/Kwh : https://www.utilitydive.com/news/new-york-battery-storage-costs-rise-interconnection-queue-12-gw/621954/ https://www.utilitydive.com/news/new-york-battery-storage-co... This is the scaling problem: if you try to deploy batteries at scales relevant to the energy grid you outstrip the supply of inputs. In order to keep up with demand, extraction industries have to tap more and more inaccessible reserves thus driving up costs. Remember, global electricity usage is 60 TWh per day. And that's just electricity, total energy use is about twice that at 120 TWh per day. Even just 12 hours of storage is hundreds of times the annual battery output - most of which isn't going to grid storage but rather electric vehicles.