4 ms·

What waves and tidal energy represent, though, is something which might be a lot more capital efficient. Yes you're much closer to the power source using photo

What waves and tidal energy represent, though, is something which might be a lot more capital efficient. Yes you're much closer to the power source using photovoltaics but they're only 20% or so efficient right now commercially. Further, the sun only shines on where I live between 8 and 16 hours a day, depending on the season. The useful average power I can expect to extract on average is about 3-4 hours per day. Waves, on the other hand, are an excellent store of energy and they persist for a long time. Easily overnight and actually over many days. So if you can reliably produce power from waves for the same capital cost per watt installed, you might get 3x-5x the energy production from the wave plant versus the solar plant. And that's before you take into account the storage necessary for solar! In other words you might be able to spend 10x on a wave power plant as a solar plant and break even. If it only costs 2-3x as much per watt, well, you're saving money. And the batteries (the ocean) are free.

darkmighty 12y ago
Solar: purchase panel and leave it in an incline for 15 years. If you have net metering you don't need to even think about storage. Wave: develop massive steel structures in the ocean and transmit power to land with low power density. It's telling that, given the possibility to pick anywhere to develop wave power (even at the most convenient locations) the tech has barely any projects.
- jacquesm 12y ago
  The tech has had many projects, but none of them made it in the longer term.
- dredmorbius 12y ago
  At some point someone has to consider storage (or alternative provisioning, or dispatchable load) for solar-backed grid. Even if it's not the homeowner with panels on their own roof.
  - alexvoda 12y ago
    Theoretically with solar panels you could have a round-the-clock, round-the-globe balanced network requiring no storage. It would be a network with the same capacity of panels on each meridian. Of course this is not very practical.
    - msandford 12y ago
      Not only not very practical but it would require entirely new transmission technologies: the maximum practical length of a 60Hz transmission line is only a few thousand miles. To go from the bright side to the dark side of the earth is worst-case 12,000 miles so new tech would be needed, or you'd just have to suffer 30% (or more) transmission line loss.
  - Intermernet 12y ago
    This is where I'm hoping the combo of electric cars and solar will pay off. The car can provide a local buffer when the family is at home during the night, but isn't needed when the sun is shining. I think the missing piece of this puzzle can hopefully be filled by something like Ambri's (previously LMBC) liquid metal battery tech [1]. A shipping container or two per suburban block, or urban building should be able to provide enough buffer, and then the load is sort-of evenly distributed, and hopefully makes the power management of the grid a little bit simpler as a side effect. [1]: http://www.ambri.com/technology/ http://www.ambri.com/technology/
deleted 12y ago
[deleted]
dredmorbius 12y ago
Energy storage is a challenge. The most effective (and most used) form of bulk storage remains pumped hydro -- it's something like 95% of all energy storage. Round-trip efficiency is high, technology is (relatively) simple, highly proven, capital costs are (relatively) low, capacities are high, response time is rapid. The disadvantage is that there just aren't all that many places which are well-suited to pumped-hydro placements. Areas with lots of water frequently have little geographic variation, and vice versa. And lakes with daily level swings of several to tens of meters are a bit dodgy for various reasons. The rest of the storage landscape reads as a list of odds and sods and bad options: batteries (small-scale, expensive, high maintenance, but fast-reacting and proven, some interesting large-scale potential), flywheels (small scale, really expensive, lots of engineering challenges, but very fast reacting), capacitors (minuscule scale relative to grid, though useful for power conditioning, horrendously expensive, blazingly fast response), compressed air (Boyles law), thermal (sizing and other issues, though potentially national-scale capable). Then there's power-to-fuels. It's not very efficient -- you lose about 50% of what you put in going to fuel, Carnot's law robs you of all but 35-40% on the way back, leaving you with 17.5% - 22.5% round-trip. If you factor in solar -- 20% efficient panels at 20% capacity factor, 90% inverter efficiency, 55% spacing factor, you're down to per-unit-area storage efficiencies which are lucky to rival biomass -- growing plants and burning them. Main difference being that you don't need to water solar panels -- in theory. In practice, washing the dust off of them helps, though they tend _not_ to get attacked by insects or birds. I've been meaning to tabulate various energy potentials, though Tom "Do the Math" Murphy's got a pretty good list of options. I really don't see wave as worth the effort.
- rndn 12y ago
  Which technology do you think is the most worthwhile one? Nuclear power?
  - dredmorbius 12y ago
    "Worthwhile" needs unpacking. For all practical purposes, we'll be solar powered in the future, though my question is at what level of technology. Woodfuel's proven robust for millennia, though there's the forests before, deserts after problem. In terms of abundance and accessibility, I'd generally say direct solar (PV or thermal), either wind or hydro, geothermal, and biomass, in about that order. It's far less a question of what's worthwhile, than what's a sustainable scale. It helps to understand what life is, and how it has transformed Earth over the past 3.5 billion years. Humans are part of that process, and, from the PoV of Earth have largely been engaged in one of the fastest redistributions of mineral resources ever seen, post primary-bombardment. https://ello.co/dredmorbius/post/5l_8MqtVwLLvX_DabPjY-g https://ello.co/dredmorbius/post/5l_8MqtVwLLvX_DabPjY-g As for nuclear generally: conventional plant designs suffer from limited fuel (80 years at present rates of use, 6 if scaled to all present human energy demands), breeders entail considerable risks, proposed thorium MSR designs haven't even landed on, let alone left, the drafting sheet, and there are complex long-term systemic risks for which I find sgcollins's "Nuke Skeptic" and "For Rohan" videos quite good. If you want more depth, I recommend Charles Perrow, The Next Catastrophe and Normal Accidents. http://fixyt.com/watch?v=KOBEloymLQA http://fixyt.com/watch?v=KOBEloymLQA http://fixyt.com/watch?v=S5hvY3atwUg http://fixyt.com/watch?v=S5hvY3atwUg http://www.powells.com/biblio/65-9780691150161-1 http://www.powells.com/biblio/65-9780691150161-1 http://www.powells.com/biblio/62-9780691004129-1 http://www.powells.com/biblio/62-9780691004129-1

darkmighty 12y ago

Solar: purchase panel and leave it in an incline for 15 years. If you have net metering you don't need to even think about storage. Wave: develop massive steel structures in the ocean and transmit power to land with low power density. It's telling that, given the possibility to pick anywhere to develop wave power (even at the most convenient locations) the tech has barely any projects.

jacquesm 12y ago
The tech has had many projects, but none of them made it in the longer term.
dredmorbius 12y ago
At some point someone has to consider storage (or alternative provisioning, or dispatchable load) for solar-backed grid. Even if it's not the homeowner with panels on their own roof.
- alexvoda 12y ago
  Theoretically with solar panels you could have a round-the-clock, round-the-globe balanced network requiring no storage. It would be a network with the same capacity of panels on each meridian. Of course this is not very practical.
  - msandford 12y ago
    Not only not very practical but it would require entirely new transmission technologies: the maximum practical length of a 60Hz transmission line is only a few thousand miles. To go from the bright side to the dark side of the earth is worst-case 12,000 miles so new tech would be needed, or you'd just have to suffer 30% (or more) transmission line loss.
- Intermernet 12y ago
  This is where I'm hoping the combo of electric cars and solar will pay off. The car can provide a local buffer when the family is at home during the night, but isn't needed when the sun is shining. I think the missing piece of this puzzle can hopefully be filled by something like Ambri's (previously LMBC) liquid metal battery tech [1]. A shipping container or two per suburban block, or urban building should be able to provide enough buffer, and then the load is sort-of evenly distributed, and hopefully makes the power management of the grid a little bit simpler as a side effect. [1]: http://www.ambri.com/technology/ http://www.ambri.com/technology/

deleted 12y ago

[deleted]

dredmorbius 12y ago

Energy storage is a challenge. The most effective (and most used) form of bulk storage remains pumped hydro -- it's something like 95% of all energy storage. Round-trip efficiency is high, technology is (relatively) simple, highly proven, capital costs are (relatively) low, capacities are high, response time is rapid. The disadvantage is that there just aren't all that many places which are well-suited to pumped-hydro placements. Areas with lots of water frequently have little geographic variation, and vice versa. And lakes with daily level swings of several to tens of meters are a bit dodgy for various reasons. The rest of the storage landscape reads as a list of odds and sods and bad options: batteries (small-scale, expensive, high maintenance, but fast-reacting and proven, some interesting large-scale potential), flywheels (small scale, really expensive, lots of engineering challenges, but very fast reacting), capacitors (minuscule scale relative to grid, though useful for power conditioning, horrendously expensive, blazingly fast response), compressed air (Boyles law), thermal (sizing and other issues, though potentially national-scale capable). Then there's power-to-fuels. It's not very efficient -- you lose about 50% of what you put in going to fuel, Carnot's law robs you of all but 35-40% on the way back, leaving you with 17.5% - 22.5% round-trip. If you factor in solar -- 20% efficient panels at 20% capacity factor, 90% inverter efficiency, 55% spacing factor, you're down to per-unit-area storage efficiencies which are lucky to rival biomass -- growing plants and burning them. Main difference being that you don't need to water solar panels -- in theory. In practice, washing the dust off of them helps, though they tend _not_ to get attacked by insects or birds. I've been meaning to tabulate various energy potentials, though Tom "Do the Math" Murphy's got a pretty good list of options. I really don't see wave as worth the effort.

rndn 12y ago
Which technology do you think is the most worthwhile one? Nuclear power?
- dredmorbius 12y ago
  "Worthwhile" needs unpacking. For all practical purposes, we'll be solar powered in the future, though my question is at what level of technology. Woodfuel's proven robust for millennia, though there's the forests before, deserts after problem. In terms of abundance and accessibility, I'd generally say direct solar (PV or thermal), either wind or hydro, geothermal, and biomass, in about that order. It's far less a question of what's worthwhile, than what's a sustainable scale. It helps to understand what life is, and how it has transformed Earth over the past 3.5 billion years. Humans are part of that process, and, from the PoV of Earth have largely been engaged in one of the fastest redistributions of mineral resources ever seen, post primary-bombardment. https://ello.co/dredmorbius/post/5l_8MqtVwLLvX_DabPjY-g https://ello.co/dredmorbius/post/5l_8MqtVwLLvX_DabPjY-g As for nuclear generally: conventional plant designs suffer from limited fuel (80 years at present rates of use, 6 if scaled to all present human energy demands), breeders entail considerable risks, proposed thorium MSR designs haven't even landed on, let alone left, the drafting sheet, and there are complex long-term systemic risks for which I find sgcollins's "Nuke Skeptic" and "For Rohan" videos quite good. If you want more depth, I recommend Charles Perrow, The Next Catastrophe and Normal Accidents. http://fixyt.com/watch?v=KOBEloymLQA http://fixyt.com/watch?v=KOBEloymLQA http://fixyt.com/watch?v=S5hvY3atwUg http://fixyt.com/watch?v=S5hvY3atwUg http://www.powells.com/biblio/65-9780691150161-1 http://www.powells.com/biblio/65-9780691150161-1 http://www.powells.com/biblio/62-9780691004129-1 http://www.powells.com/biblio/62-9780691004129-1