3 ms·

Kind of curious but I think people can get side-tracked by the idea of "scale". The thought that if something doesn't scale in the traditional way to a few very

Kind of curious but I think people can get side-tracked by the idea of "scale". The thought that if something doesn't scale in the traditional way to a few very large installations, it won't work. Consider things like battery storage for the grid etc. and you might think it is a dead horse. However, what if every house had solar panels and a relatively small number of cells with a grid-tie unit. I no longer need to store an enormous amount of energy, just enough for perhaps a few hours of demand for my house. You get to soak up most of the high-sun days into batteries, you can also feed each other a little if someone is using a fair bit more energy along existing small cables. You can then feed in a much smaller number of larger power plants who can make up any remaining peaks and troughs. Don't need to store 1TW of power into a grid-scale plant, just 20M 10KW systems distributed round the entire country. Don't need to point the panels at the sun all day then!

zdragnar 4y ago
It's really location-dependent. The upper midwest US can go weeks without direct sunshine or much wind in late December through the first week of February. Batteries fed by solar simply won't suffice- even on sunny days, there are fewer hours of sun. To reduce the number of power plants in the area, we'd need to import electricity from elsewhere, at which point you need to overprovision some geographies and run significant amounts of HVDC lines across the country. Neither of these are free or without their own impacts. Whether that would be better than fission or waiting for fusion or continuing with natural gas is debatable- steel and aluminum are not entirely coal free yet either, nor is the concrete or any of the construction work. OTOH, very sunny areas like the southwest could do quite well here.
- WaitWaitWha 4y ago
  > OTOH, very sunny areas like the southwest could do quite well here. from the article: > Locations must be chosen carefully to avoid tidal forces and stormy weather from destroying the panels as well as their mooring and anchoring systems. That sort of removes anywhere we have hurricanes, tropical cyclones, typhoons and such; mostly where we have ample sun. That said, it does look interesting. Maybe if they have some more built-in self protection from weather?
  - zdragnar 4y ago
    Anything in a climate that could freeze would require heating elements much like windmills currently do. Unfortunately, windmills don't accumulate ice very quickly, compared to a floating solar panel would in say Lake Superior in winter. I imagine that hurricanes would also rule out much of the east coast and gulf of mexico, leaving... California and Hawaii?
- kibwen 4y ago
  In this specific example, the Midwest is ideal for wind farms: https://www.eia.gov/energyexplained/wind/where-wind-power-is-harnessed.php https://www.eia.gov/energyexplained/wind/where-wind-power-is... . Wind is already the majority of the energy generated in Iowa: https://en.m.wikipedia.org/wiki/Wind_power_in_Iowa https://en.m.wikipedia.org/wiki/Wind_power_in_Iowa So as far as being location-dependent, indeed it is, though that doesn't preclude other renewable solutions.
  - zdragnar 4y ago
    Since I am from further north, I consider Iowa to be more Midwest than upper Midwest. We do have some wind mills around, but they are stationary more often than not, especially in the period I mentioned in January where we don't get much sun or wind. If we littered the landscape of Iowa with enough windmills to fill chemical or mechanical batteries, though, that might cut down on the distance we need to import energy at least.
kkfx 4y ago
There are few issues about floating p.v.: sometimes the water is calm and flat so p.v. works. Sometimes not. Did you imaging what happen not just in mere structural terms but ALSO in string output? BTW I have p.v. at home, a NEW home so well insulated and all-electrical equipped, while I'm in the French southern Alps (at 1030m) so in a VERY GOOD place for p.v. y-o-y I hardly reach 50% self consumption. Now with an EV I need at minimum 18kWp p.v. to just charge A BIT my EV from Sun while WFH... That's because in winter, just today, I have had plenty of Sun from 9:30 to 13:30 so in just 4 hours I need to recharge a car (let's say it's not that empty, let's say 40kWh), heat water for house heating and sanitary hot water, plus all other home appliances I can concentrate in 4 hours in the morning. Imaging what can do those who not WFH and who live in less p.v. friendly areas... EVs are the formally untold way to have a THEORETICALLY stable smart grid (who do not exists in the real world so far) witch significant renewable productions with their pick loads. The EVs are mostly connected in big numbers across a country all the time and they tend to be in large number not fully charged not fully discharged so they can theoretically quickly start charging full-power and the slow down or quickly discharge to the grid full-power and then slow down allowing classic large power plants we need anyway to have time to regulate their production keeping the grid operation at the right frequency. A way to offload enormous short-life storage costs to the people instead to the large utilities. But no, as a small domestic p.v. "user" and an engineer I see NO WAY for a society to run on p.v. on scale with the actual tech. We can do MUCH more, like creating en masse new homes to lower enormously heating and cooling energy needs, we can subsidize EVs on scale and spread bi-directional service in pure DC to use them like any stationary p.v. lithium storage (they are already 400V DC anyway on both sides for 99% of the available gears on sale) to allow a stable grid while pushing p.v. up but without something else we have no option to keep a modern society operational on scale.
- pencilguin 4y ago
  It should be obvious that it would be foolish to expect to meet all your power needs, including EV charging, with a small rooftop installation. Rooftop solar is to cut down on your power bill. "For a society to run on PV on scale" you of course rely on municipal, commercial, and regional "actual tech" solar and wind installations, storage, transmission lines and backup peaker plants to make up the difference. Some storage might involve lithium batteries, or other chemistries, or non-chemical methods such as pumped hydro or other gravitational methods, compressed or liquified air, or synthetic fuels such as hydrogen and ammonia; and commonly a mix of the above. Floating PV is sited at places where the water is habitually calm; calm water is always flat. Reservoirs and canals are favored sites, as noted in the article. Nobody talks about floating PV on breaking shore waves. It is hard to guess what could be meant by "string output", if anything, unique to floating PV. Solar panel output is the same, terrestrial or floating, and is handled the same way. We are fortunate that planning for regional renewable power does not depend on people who cannot see how they would deploy it. Others, including other engineers, can and do. Floating solar will be sited throughout most of the world. Ice on a solar panel does not reduce its output much, but being embedded in ice that, finally, breaks up could be damaging. Engineers are good at designing for local conditions. The article makes a big deal of imaginary shortfalls of available land for solar, but there is in fact very far from any such shortage. So, solar will always be sited wherever it is cheapest. Some places, it will be floated. Other places, it will share pasturage or crop land. Others, commercial warehouses. In France it will be, by statute, on all big parking lots.
PaulDavisThe1st 4y ago
Consider a climate with a heating season. Imagine the use of air-source heat pumps (USA "minisplits"). Heating season arrives. Electrical use multiplies, perhaps 10x compared to non-heating season. Where does the power come from? Home installations generally won't cover it. Centralized installations may (hopefully will), but the power is needed even more overnight than during the day. I still think you're going to need pretty substantial central storage facilities.
- pencilguin 4y ago
  So you build out storage facilities. Whatever turns out cheapest for a given site wins. Different sites will favor different winners. We don't know yet which few of myriad choices that all work will turn out cheapest, but probably not batteries beyond a few hours' time-shifting. There is little value in central storage, except in methods where economy of scale rules. Storage can otherwise be distributed as widely as convenience suggests, and the power moved around on wiring. Of course you don't build out storage until you have enough spare renewable generating capacity to charge it from. In the meantime you fill shortfalls from peaker plants, the usual way. As synthetic fuels like hydrogen and ammonia become cheaper than NG, peakers will be fired with them, either synthesized locally or imported, when cheaper storage runs low.

zdragnar 4y ago

It's really location-dependent. The upper midwest US can go weeks without direct sunshine or much wind in late December through the first week of February. Batteries fed by solar simply won't suffice- even on sunny days, there are fewer hours of sun. To reduce the number of power plants in the area, we'd need to import electricity from elsewhere, at which point you need to overprovision some geographies and run significant amounts of HVDC lines across the country. Neither of these are free or without their own impacts. Whether that would be better than fission or waiting for fusion or continuing with natural gas is debatable- steel and aluminum are not entirely coal free yet either, nor is the concrete or any of the construction work. OTOH, very sunny areas like the southwest could do quite well here.

WaitWaitWha 4y ago
> OTOH, very sunny areas like the southwest could do quite well here. from the article: > Locations must be chosen carefully to avoid tidal forces and stormy weather from destroying the panels as well as their mooring and anchoring systems. That sort of removes anywhere we have hurricanes, tropical cyclones, typhoons and such; mostly where we have ample sun. That said, it does look interesting. Maybe if they have some more built-in self protection from weather?
- zdragnar 4y ago
  Anything in a climate that could freeze would require heating elements much like windmills currently do. Unfortunately, windmills don't accumulate ice very quickly, compared to a floating solar panel would in say Lake Superior in winter. I imagine that hurricanes would also rule out much of the east coast and gulf of mexico, leaving... California and Hawaii?
kibwen 4y ago
In this specific example, the Midwest is ideal for wind farms: https://www.eia.gov/energyexplained/wind/where-wind-power-is-harnessed.php https://www.eia.gov/energyexplained/wind/where-wind-power-is... . Wind is already the majority of the energy generated in Iowa: https://en.m.wikipedia.org/wiki/Wind_power_in_Iowa https://en.m.wikipedia.org/wiki/Wind_power_in_Iowa So as far as being location-dependent, indeed it is, though that doesn't preclude other renewable solutions.
- zdragnar 4y ago
  Since I am from further north, I consider Iowa to be more Midwest than upper Midwest. We do have some wind mills around, but they are stationary more often than not, especially in the period I mentioned in January where we don't get much sun or wind. If we littered the landscape of Iowa with enough windmills to fill chemical or mechanical batteries, though, that might cut down on the distance we need to import energy at least.

kkfx 4y ago

There are few issues about floating p.v.: sometimes the water is calm and flat so p.v. works. Sometimes not. Did you imaging what happen not just in mere structural terms but ALSO in string output? BTW I have p.v. at home, a NEW home so well insulated and all-electrical equipped, while I'm in the French southern Alps (at 1030m) so in a VERY GOOD place for p.v. y-o-y I hardly reach 50% self consumption. Now with an EV I need at minimum 18kWp p.v. to just charge A BIT my EV from Sun while WFH... That's because in winter, just today, I have had plenty of Sun from 9:30 to 13:30 so in just 4 hours I need to recharge a car (let's say it's not that empty, let's say 40kWh), heat water for house heating and sanitary hot water, plus all other home appliances I can concentrate in 4 hours in the morning. Imaging what can do those who not WFH and who live in less p.v. friendly areas... EVs are the formally untold way to have a THEORETICALLY stable smart grid (who do not exists in the real world so far) witch significant renewable productions with their pick loads. The EVs are mostly connected in big numbers across a country all the time and they tend to be in large number not fully charged not fully discharged so they can theoretically quickly start charging full-power and the slow down or quickly discharge to the grid full-power and then slow down allowing classic large power plants we need anyway to have time to regulate their production keeping the grid operation at the right frequency. A way to offload enormous short-life storage costs to the people instead to the large utilities. But no, as a small domestic p.v. "user" and an engineer I see NO WAY for a society to run on p.v. on scale with the actual tech. We can do MUCH more, like creating en masse new homes to lower enormously heating and cooling energy needs, we can subsidize EVs on scale and spread bi-directional service in pure DC to use them like any stationary p.v. lithium storage (they are already 400V DC anyway on both sides for 99% of the available gears on sale) to allow a stable grid while pushing p.v. up but without something else we have no option to keep a modern society operational on scale.

pencilguin 4y ago
It should be obvious that it would be foolish to expect to meet all your power needs, including EV charging, with a small rooftop installation. Rooftop solar is to cut down on your power bill. "For a society to run on PV on scale" you of course rely on municipal, commercial, and regional "actual tech" solar and wind installations, storage, transmission lines and backup peaker plants to make up the difference. Some storage might involve lithium batteries, or other chemistries, or non-chemical methods such as pumped hydro or other gravitational methods, compressed or liquified air, or synthetic fuels such as hydrogen and ammonia; and commonly a mix of the above. Floating PV is sited at places where the water is habitually calm; calm water is always flat. Reservoirs and canals are favored sites, as noted in the article. Nobody talks about floating PV on breaking shore waves. It is hard to guess what could be meant by "string output", if anything, unique to floating PV. Solar panel output is the same, terrestrial or floating, and is handled the same way. We are fortunate that planning for regional renewable power does not depend on people who cannot see how they would deploy it. Others, including other engineers, can and do. Floating solar will be sited throughout most of the world. Ice on a solar panel does not reduce its output much, but being embedded in ice that, finally, breaks up could be damaging. Engineers are good at designing for local conditions. The article makes a big deal of imaginary shortfalls of available land for solar, but there is in fact very far from any such shortage. So, solar will always be sited wherever it is cheapest. Some places, it will be floated. Other places, it will share pasturage or crop land. Others, commercial warehouses. In France it will be, by statute, on all big parking lots.

PaulDavisThe1st 4y ago

Consider a climate with a heating season. Imagine the use of air-source heat pumps (USA "minisplits"). Heating season arrives. Electrical use multiplies, perhaps 10x compared to non-heating season. Where does the power come from? Home installations generally won't cover it. Centralized installations may (hopefully will), but the power is needed even more overnight than during the day. I still think you're going to need pretty substantial central storage facilities.

pencilguin 4y ago
So you build out storage facilities. Whatever turns out cheapest for a given site wins. Different sites will favor different winners. We don't know yet which few of myriad choices that all work will turn out cheapest, but probably not batteries beyond a few hours' time-shifting. There is little value in central storage, except in methods where economy of scale rules. Storage can otherwise be distributed as widely as convenience suggests, and the power moved around on wiring. Of course you don't build out storage until you have enough spare renewable generating capacity to charge it from. In the meantime you fill shortfalls from peaker plants, the usual way. As synthetic fuels like hydrogen and ammonia become cheaper than NG, peakers will be fired with them, either synthesized locally or imported, when cheaper storage runs low.