9 ms·

I think the future will be robust national/international grids, with a mixture of storage options (batteries/pumped hydro) to smooth out the intermittent nature

• manfredo 6y ago
  Even achieving just one hour of storage globally amounts to 2.5 TWh of storage. By comparison the entire world produces ~300 GWh worth of lithium ion battery annually. That leaves geographically limited options like pumped hydroelectricity, and solutions not yet deployed at any significant scale like hydrogen fuel cells, synthetic methane, thermal batteries, flywheels, etc. Realistically we should saturate daytime energy demand with solar, and if there aren't any scalable storage options by then switch gears and proceed with hydroelectric where it's viable and nuclear where it's not.
  • nicoburns 6y ago
    > Even achieving just one hour of storage globally amounts to 2.5 TWh of storage. By comparison the entire world produces ~300 GWh worth of lithium ion battery annually ... so if we could increase battery production by just 10x, then we could create an hours worth of storage every year. That seems... very doable.
    • thiht 6y ago
      That sounds extremely expensive and not very green.
    • manfredo 6y ago
      And then we'd have to continue that production for two and a half decades to get to 1 day of storage. And we'd also have to drastically increase our battery recycling capacity to match (remember most lithium ion batteries last 1000-2000 cycles).
      • jeffbee 6y ago
        Nobody needs 1 full day of storage.
        • ch4s3 6y ago
          One could imagine a series of cloudy windless days in the northern latitudes during the winter. Perhaps a large enough gird solves that problem? I have no clue.
          • lutorm 6y ago
            But the key is that if you're averaging globally, the solar power probably doesn't change much. You'll need a way to transport the energy instead, obviously.
          • pfdietz 6y ago
            One would not use batteries for the "rare, but prolonged" storage use case. You'd want something with lower capital cost, even if it were much less efficient. For example: hydrogen burned in turbines.
            • Manfredo_1 6y ago
              Hydrogen storage remains in the prototyping phase. We have no significant amount of hydrogen grid storage. Like thermal batteries or synthetic methane, hydrogen represents a potential storage solution but not one that we know will scale and be effectively deployed at the scope required. If we actually deploy 50 GWh of hydrogen storage, and demonstrate that it can cheaply and reliability be built at scale then your point would be valid. But until then, hydrogen represents a theoretical solution not an actual solution.
              • pfdietz 6y ago
                All the components of hydrogen, with the possible exception of low cost electrolyzers, don't need to be prototyped. It's existing technology. It's not like (say) molten salt reactors, in which fundamental development remains to be done.
  • jkinudsjknds 6y ago
    That 2.5TWh is probably an hour of active daytime usage though, no?
  • pydry 6y ago
    >Even achieving just one hour of storage globally amounts to 2.5 TWh of storage. By comparison the entire world produces ~300 GWh worth of lithium ion battery What's the point of this comparison? Lithium ion batteries are probably the least cost effective means of dealing with intermittency. It's also rare that the entire world is without wind and sun simultaneously. In terms of cost: Demand shaping < overproduction < pumped storage < < lithium ion batteries
    • Manfredo_1 6y ago
      "Demand shaping" is a nice euphemism for energy shortages. And if we demand shaping we're just externalizing the cost to consumers that need to buy their own energy storage or change their energy usage patterns to accommodate the unreliable supply. Overproduction helps but doesn't eliminate intermittency. And pumped hydroelectricity is geographically dependent. The irony is that most places with extensive hydroelectric storage potential don't need wind and solar in the first place because they get their energy from hydroelectric generation.
      • asdfasgasdgasdg 6y ago
        There is always a shortage of electricity. Someone could always use more if it were free to do so. Economics is the study of the allocation of resources in the face of scarcity -- that is, all allocation of resources except perhaps breathable air. There's no need for a euphemism here because limitations on the consumption of energy are ever-present -- demand shaping is simply about making the signal stronger.
        • Manfredo_1 6y ago
          There are rarely shortages of electricity in the US. There were some in California during Covid, and the state had to do rolling blackouts. But no, there are rarely shortages of electricity. Yes, someone could use more of it than we could supply. But they don't. The existing supply is sufficient to meet demand. And when demand changes, we are capable of increasing supply.
      • 6y ago
  • psadri 6y ago
    We could use day time electricity to generate fuels to burn at night. As long as it’s net-zero wrt to CO2 emissions, it will be fine.
  • mgolawala 6y ago
    Why would we use lithium ion batteries? I would imagine the approach to store the energy would be to use the energy from solar panels to do work that can be used to produce electricity later. For example, you could use solar energy to pump water back uphill to flow down through a hydro electric dam later. Even if it isn't the most efficient, in the long run it would likely provide the best scalability and least long term environmental impact. Once you have the facility in place, the same water could be pumped uphill to flow back down a million times over with the only overhead replacing water lost through evaporation and maintaining the facility. Am I missing something that makes such an approach unfeasible?
    • kragen 6y ago
      My comment at https://news.ycombinator.com/item?id=26597661 https://news.ycombinator.com/item?id=26597661 links to a number of overviews of the issue, including MacKay's chapter in which he covers pumped storage in about as much depth as you can possibly hope in a 20-page chapter aimed at a general audience. Go read it!
    • manfredo 6y ago
      Hydroelectric storage is geographically dependent. You need the right topography and access to water. Likewise, hydroelectric storage takes a long time to build.
  • Qwertious 6y ago
    >By comparison the entire world produces ~300 GWh worth of lithium ion battery annually. And this will increase a hundredfold to make EV production possible. That means that if 10% of production goes to stationary storage then within 10 years, we'll have 10 full global hours of storage. If there's serious demand then the supply will scale up to create it. Also, old EV batteries will provide plenty of extra stationary storage. Not to mention batteries still in EVs, in a pinch. Realistically we won't throw insane amounts of storage at the problem. We'll make demand more flexible so it does work when electricity is cheap and eases off when it becomes more expensive. For instance, something like heating: why store the electricity for heating? Wouldn't it make more sense for a house to have some form of heavily-insulated thermal mass that it can massively heat when electricity is dirt cheap, then tap into at midnight without drawing power? Storing heat is cheap, you just need a giant block of concrete with solid insulation. You don't need fancy nanoscale tech like with lithium-ion. Even something like a kettle: the hot water taps you see at companies that are pre-heated. Have a home-version. Insulate the shit out of that and do 90% of the boiling with peak electricity. And that's not even touching industrial power usage. Trying to ape past systems that were based on flat electricity prices just seems like a failure of imagination. Of course it would be expensive, but why the heck would you even want to?
    • Symbiote 6y ago
      The heater you describe is called a storage heater. https://en.wikipedia.org/wiki/Storage_heater https://en.wikipedia.org/wiki/Storage_heater
    • cmcnab 6y ago
      I had a house for a time that had just what you describe: a concrete block thermal mass set in the foundation. There were ducts running through it as part of the forced-air system. During the days, especially sunny days, the block soaked up the excess heat and then radiated it back out during the night. It worked quite well; indoor temperatures stayed remarkably consistent. A company called Adirondack Alternate Energy were the architects. https://aaepassivesolar.com/low-energy.html https://aaepassivesolar.com/low-energy.html
  • intrepidhero 6y ago
    Let me introduce you to flow batteries. Lithium is a terrible choice for grid scale storage, except maybe as a secondary use of idle EVs. https://en.m.wikipedia.org/wiki/Flow_battery https://en.m.wikipedia.org/wiki/Flow_battery
• flgb 6y ago
  I suspect most of the intermittency of wind and solar will be addressed through super-capacity (500% of peak demand, not 100%) and geographic diversity. Batteries will be used for very short-term local balancing and power regulation ... then for those occasional times when hydro, wind and solar don’t cut it, we’ll still burn a little gas but it will be bio gas or green hydrogen, rather than fossil gas. This gas will be expensive, but these plants will hardly ever run.
  • grayfaced 6y ago
    Or super-capacity could be used on energy intensive operations, such as desalination plants.
  • zizee 6y ago
    I agree entirely. I chose the 1 hour of storage as a number because I had to say something, and I didn't want to go to low as it would undoubtedly knee jerk responses of "that's not enough, you need X hours". The main point I was going for is that we shouldn't think of a national network in the same way as we think of a off grid house with solar, where you have to deal with many hours without sunlight, and have storage capacity for several days of rain. In a similar vein, the intermittency of solar and wind look bad when you look at isolated generation instances, but when you have a continent spanning network, the intermittency is reduced as the wind is always blowing somewhere, and the sun is shining for many more hours than when you look at any single point on map. Again, I would love to see the numbers if you were plan out a realistic build out of this ideal network. It would probably be a pretty big number, but how would it compare to building out with nuclear, or even just lots of coal power plants from scratch.
  • Hypx 6y ago
    Super-capacity is going to be a major driver for the build-out of water electrolysis for the production of hydrogen. You can turn what will basically be a waste product into a highly useful fuel. I've seen people contend that this will be expensive, but given the very cheap input costs I believe this will be a very cheap process.
• gruez 6y ago
  >international grids Europe didn't want to act when russia invaded crimea, because russia supplied all the gas. Being dependent on your neighbors for your electricity supply and having no backup would only make this problem worse.
  • meepmorp 6y ago
    Isn't that an argument for greater integration, to provide redundant sources of energy?
  • scoopertrooper 6y ago
    But solar would effectively level the playing field. Countries would become interdependent upon one another for energy rather than being dependent.
• dukeofdoom 6y ago
  So I've been watching these Van build outs into full time living vans for travel. Most of them have solor panels on the roof, and 3 two hundred watt batteries. One guy said it would take him 23 days to fully charge these batteries off of solar vs just a few hours to charged them from the alternator when he is driving. It just doesn't seem very practical at this point. They all seem to have 2 or 3 thousand watt panels on the roof. Is he correct? How does the math work here? How long should it take for a 1000 Watt panel to charge a two hundred watt battery?
  • philipkglass 6y ago
    I think that your recollection is incomplete or garbled. Modern solar panels are about 20% efficient. They can generate about 200 watts per square meter in midday sun with clear skies. 2000 to 3000 watts of panels would be about 10-15 square meters (107-161 square feet). Do these vans actually have roofs that large, completely covered with panels? You might expect roof top panels with sub-optimal orientation to generate about 12.5% of their peak rating when averaged over a year. That would be 375 watts, annualized, from a system with a peak capacity of 3000 watts. There is no van-portable battery system currently on the market that can store 375 * 24 * 23 = 207,000 watt-hours. (For comparison, the Tesla Model S battery stores 100,000 watt-hours.) My guess is that you are not correctly recalling how much solar capacity these vans have installed. When I Google for van life solar I get guides and kits referencing much less power. For example, this guide: https://www.genericvan.life/2018/04/30/complete-vanlife-solar-system-for-under-1000/ https://www.genericvan.life/2018/04/30/complete-vanlife-sola... uses a single 150 watt panel. Based on the photo the article includes, I don't think that the van rooftop has room for more than 3 panels of this type.
    • dukeofdoom 6y ago
      Yes, sorry, I think I got the numbers wrong by a factor of ten. Most seem to use two or three 100 watt panels. So 300 watts is what they are getting in total for most of these build outs. But they usually leave space for fans. So I think absolute max might be something closer to double that. So can you answer with this correction?
  • 6y ago
• elihu 6y ago
  I wonder what the limits are on transmitting power around the world? Like, if we wanted to connect Northern Africa to the North American power grid, how feasible would it be, and what would the losses and power capacity be? It seems that with all the interest in using ReBCO tape in tokomaks due to its ability to transmit more power at higher temperatures than the materials that preceded it (used, for example in ITER) that it could be used to transmit power over long distances. Has anyone actually done it yet, or is it just too expensive? (Apparently the current capacity of superconducting cable is finite; if you run too much current through it, it'll transition to becoming non-superconducting. So maybe the amount of ReBCO tape needed per unit of power or the amount of active cooling needed makes it impractical.) Eventually, to be able to usefully transmit power from daytime sun to nighttime will require crossing oceans. Which I imagine would be tough to do with a cable has to be actively cooled and work for many years without maintenance. Maybe for my hypothetical North America to North Africa route, you'd run a superconducting cable down through Central and South America over to Brazil, then have a normal high-voltage DC line across the Atlantic, with another superconducting cable that crosses the Sahara.
  • fpgaminer 6y ago
    I dunno, back of the envelope says you'd only lose 33% with today's HVDC lines from North Africa to North America. The ocean will sink the lost energy for us. And we can make up the difference with more solar/wind, which is cheap. Superconducting would be nice to have, but doesn't seem necessary.
    • elihu 6y ago
      Huh, that's actually not bad. That makes the idea of connecting Asia/Africa/Europe with the Americas for 24-hour solar power seem doable. I assume it would be tremendously expensive to build, but also have substantial benefits long into the future.
      • mtalhaashraf 6y ago
        The level of dependency on others and the associated risks would likely discourage this
• netflixandkill 6y ago
  It's not cynicism, it's understanding capacity factors and how difficult large scale storage is. If solar panels have a capacity factor of around .25, which is what we're seeing in real installations worldwide, then it is necessary to overproduce by at least 4x and store it somewhere for off-peak solar production hours. It's even worse if there is not other dispatchable generation available unless people are willing to accept periodic blackouts. We're in the process of building out a combined solar and battery installations in Guam, which is about the ideal case with predictable weather, predictable load, little heavy industry and low potential for load growth. It'll enable them to retire all their old fuel oil generators, but they'll be keeping the diesel/LNG plant for at least the next 30 years even if they only run it a few days worth of time every month.
  • toomuchtodo 6y ago
    That Guam use case would be perfect to trial combined desal and hydrogen production and storage for production troughs instead of keeping the diesel genny. Saltwater and renewables goes in, clean water and hydrogen come out.