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>> In a world of _very_ poor options for energy storage Many startups are working on solving that, and some, like Ambri's liquid metal batteries aim towards a

by petra 11y ago

>> In a world of _very_ poor options for energy storage Many startups are working on solving that, and some, like Ambri's liquid metal batteries aim towards a cost of 1 cent for storing a kwh. Considering that currently some PV solar is sold at 5 cents/kwh , and there's some improvement left , and with a huge amount of money being invested in PV solar - it would be really hard for heat storage(maybe 12.5 cents/kwh) to compete. As for scalability: It's hard to tell , but at least some of those storage options get funding by ARPA-E and the like, so i assume they have some scalability, even though i don't know the chemistry details.

dredmorbius 11y ago
There are startups working on the problem, but we've move very little since Jules Vernes' day, when he envisioned a future hydrogen economy. For now, we're up against: 1. Far too few good sites for pumped hydro, the most cost-effective and round-trip efficient, as well as proven, option. Seawater-based pumped hydro exploiting oceans as a lower reservoir and areas of high coastal elevation gain may offer some additional option. 2. Biomass. Which is what coal, oil, and gas are. Simply, not at current scales. Biomass accounting for a few percent of total present energy use might work, but at present (or forecast) energy usage rates, simply not scalable. 3. Batteries face chemical barriers and substrate availability. Most offer only 1/100th the energy storage density of hydrocarbons (by weight or volume). At scales contemplated, lead and lithium are both critically constrained resources. Super-abundant salts, or organic compounds, might work. But you're still left with scale-of-operation. 4. Compressed air energy storage (CAES) is something my buddies at the US National Energy Labs tell me to keep an eye on, though I'm dubious. Boyle's Law and thermal losses through compression and expansion are problematic. But maybe. 5. Fuel synthesis. 50 years of research, no production systems. That worries me. A lot. But the basic science is sound. Problems: energy cost of liquid hydrocarbon fuels increase 80x over current, and your round-trip efficiencies are on the order of 17-22%. Good news is that storage stability is proven for millions of years. 6. Kinetic systems: flywheels. Engineering challenges (precession's a bitch), very low energy densities, very high costs. They're highly responsive, but other than short-term (sub-second to several minutes) of power conditioning, not an option.
- petra 11y ago
  We we're dicussing grid energy storage, now you mention the fuels problem. sure that's a bigger/different problem. >> Super-abundant salts, or organic compounds, might work. But you're still left with scale-of-operation. Please explain ? Assuming we have all the materials at a cheap enough costs - we just need to build , no?
  - dredmorbius 11y ago
    Battery (redox) storage is sufficiently low-density that you're starting to talk about significant land area simply dedicated to energy storage (same applies to most other options -- again, thermal salt energy storage is among the denser options availabe). Keep in mind that that's not only large areas, probably poorly co-locatable with other uses (liquid / molten salt batteries at 600F and residential areas don't mix well given accident risk -- the substrates are relatively safe, but anything in volume at 600F is a hazard), but they're hugely technical large land areas. That's already a challenge for virtually all solar energy options. Factor in likley 10-20 year lifecycle, and you're talking about large land areas with 5-10% annual replacement requirements -- a lot of O&M expense and reinvestment.

by petra 11y ago

dredmorbius 11y ago

There are startups working on the problem, but we've move very little since Jules Vernes' day, when he envisioned a future hydrogen economy. For now, we're up against: 1. Far too few good sites for pumped hydro, the most cost-effective and round-trip efficient, as well as proven, option. Seawater-based pumped hydro exploiting oceans as a lower reservoir and areas of high coastal elevation gain may offer some additional option. 2. Biomass. Which is what coal, oil, and gas are. Simply, not at current scales. Biomass accounting for a few percent of total present energy use might work, but at present (or forecast) energy usage rates, simply not scalable. 3. Batteries face chemical barriers and substrate availability. Most offer only 1/100th the energy storage density of hydrocarbons (by weight or volume). At scales contemplated, lead and lithium are both critically constrained resources. Super-abundant salts, or organic compounds, might work. But you're still left with scale-of-operation. 4. Compressed air energy storage (CAES) is something my buddies at the US National Energy Labs tell me to keep an eye on, though I'm dubious. Boyle's Law and thermal losses through compression and expansion are problematic. But maybe. 5. Fuel synthesis. 50 years of research, no production systems. That worries me. A lot. But the basic science is sound. Problems: energy cost of liquid hydrocarbon fuels increase 80x over current, and your round-trip efficiencies are on the order of 17-22%. Good news is that storage stability is proven for millions of years. 6. Kinetic systems: flywheels. Engineering challenges (precession's a bitch), very low energy densities, very high costs. They're highly responsive, but other than short-term (sub-second to several minutes) of power conditioning, not an option.

petra 11y ago
We we're dicussing grid energy storage, now you mention the fuels problem. sure that's a bigger/different problem. >> Super-abundant salts, or organic compounds, might work. But you're still left with scale-of-operation. Please explain ? Assuming we have all the materials at a cheap enough costs - we just need to build , no?
- dredmorbius 11y ago
  Battery (redox) storage is sufficiently low-density that you're starting to talk about significant land area simply dedicated to energy storage (same applies to most other options -- again, thermal salt energy storage is among the denser options availabe). Keep in mind that that's not only large areas, probably poorly co-locatable with other uses (liquid / molten salt batteries at 600F and residential areas don't mix well given accident risk -- the substrates are relatively safe, but anything in volume at 600F is a hazard), but they're hugely technical large land areas. That's already a challenge for virtually all solar energy options. Factor in likley 10-20 year lifecycle, and you're talking about large land areas with 5-10% annual replacement requirements -- a lot of O&M expense and reinvestment.