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Recently I saw on HN that Australia has a path to >98% renewable energy (solar, wind, hydro) with only 5 hours of battery storage. That’s a lot of value for le

• 01100011 4y ago
  Do you believe it? Solar+wind has had several notable failures so far when overcast skies combined with windless conditions. Hydro probably helps to a great degree though.
  • pfdietz 4y ago
    Rare dark/calm periods can be countered by storage technologies other than batteries. These technologies typically have lower efficiency than batteries, but that doesn't matter when they're only rarely called on. For these technologies, low per-energy-stored capital cost is much more important than high efficiency. As an example: hydrogen can be stored in solution-mined salt caverns for as little as $1/kWh of storage capacity.
    • 01100011 4y ago
      Context my friend. Read what OP and I are talking about and note how your post has nothing to do with it. We're certainly not discussing things which are currently in the realm of unrealized dreams.
      • ncmncm 4y ago
        Please do not post shallow, dismissive, uninformed remarks. When you have nothing to offer, as here, you need not post at all.
      • pfdietz 4y ago
        I was giving a solution to the obstacle you pointed out. It doesn't get more relevant than that.
        • 01100011 4y ago
          Sorry for my tone. Op mentioned someone doing a simulation that claimed that scaled up solar+wind+hydro generation with only 5 hours of storage capacity would be sufficient to meet the needs of Australia. That seems odd given that cloudy, windless conditions can last for days in many cases. You would at least need sufficient storage+hydro capacity to cover several days worth of shortfalls from wind+solar. Battery systems are great. Pumped hydro storage is great. But I'm unaware of such systems coming anywhere close to the capacities required in the near term. At this point, the hydrogen infrastructure is years away. It looks like hydrogen storage underground is sufficiently proven to be feasible, but there are a host of other issues in the hydrogen energy chain that need to be addressed, most notably green generation at scale.
          • ncmncm 4y ago
            Green storage at scale does not exist yet because the equipment to do it has not been built yet. The equipment has not been built yet because the factories to build it are still under construction, and because money is still overwhelmingly better spent building out renewable generating capacity needed to charge it from. Storage you cannot fill up is wasted money. People responsible for keeping the grid operating are not at all worried about their ability to continue, using renewables and storage that will be built. In places and times where renewable generation falls short for longer than local storage can cover, energy will be imported from places with an excess, via transmission lines or shipments of synthetic fuel, most likely liquified anhydrous ammonia. Until that is available in sufficient quantity, they will burn NG during those shortfalls. The amount burnt will be much, much less than is today. Producing and then storing hydrogen underground takes very little of "hydrogen infrastructure". H2 may be generated, stored, and drawn down all within a single facility built over or near the underground storage cavity. The power involved may be moved in or out by transmission lines.
          • swid 4y ago