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Is there some kind of practical limit to renewable electricity production due to how difficult it is to store and its intermittent nature. My intuition tells me

Is there some kind of practical limit to renewable electricity production due to how difficult it is to store and its intermittent nature. My intuition tells me it can never quite be 100%. How wrong am I?

Smaug123 3y ago
Well, in principle one could store solar energy in the form of a flammable fuel which can be used to rapidly spin up a turbine, by constructing ethanol/methane from carbon dioxide and water. We can't do it at scale yet, but this is the realm of e.g. Prometheus Fuels.
hn_throwaway_99 3y ago
Batteries exist (and are getting better). Most of the intermittent nature of renewables is just solving for the timing issue (e.g. evening when demand is high and the sun goes down), so short term storage is what's most in demand. Longer term storage is harder (e.g. it's cloudy for days on end), but even then there are renewable storage options like pumped hydro and generation of natural gas from electricity.
thinkcontext 3y ago
It is true the amount of storage needed goes up the higher the percentage of intermittent generation on the grid. There are various models that say it can be done but it requires overbuilding generation and substantial investment in transmission in addition to storage. It's for sure a hard problem.
dahart 3y ago
Hydro never stops. Wind and solar are cyclical, but even aside from electrical batteries, there are multiple companies designing energy storage systems (cf EnergyVault which has been making rounds in the news https://www.energyvault.com/ https://www.energyvault.com/).
- worik 3y ago
  > Hydro never stops It does. In droughts
  - jackjeff 3y ago
    Indeed. I wonder what happens in summer in case of drought. This links partially answers my question. https://app.electricitymaps.com/zone/PT https://app.electricitymaps.com/zone/PT Apparently 33% was pumped storage (wow). And it’s a windless night so no other renewables. 17% gas that produces the CO2. That is quite impressive. Won’t compete with the crazy hydro of Norway/Sweden or the nuclear of France. But it’s quite a decent chunk of carbon free power.
generic92034 3y ago
If you are willing to build a whole lot of infrastructure for storage and accept the efficiency loss due to the conversion then you can probably get pretty close to 100%. See also: https://en.wikipedia.org/wiki/Power-to-gas https://en.wikipedia.org/wiki/Power-to-gas
worik 3y ago
Not wrong. Some renewables are consistent particularly geothermal, hydro, and biomass Geothermal is not available everywhere with current tech Hydro ditto, (must have mountains) it is hugely destructive, and is intermittent on an actual scale (dry years) Biomass is expensive and hungry for land. So it is not simple. It is doable, and essential if we are to continue lifestyles anything vaguely like what we have, but it requires careful planning and cooperation The current "Big Capital" model is not well suited. More local, small scale, and distributed generation and storage are where we need to head, IMO
matsemann 3y ago
Norway is at 98% renewable, at least.
- missedthecue 3y ago
  Hydro. The whole world could run off hydro if there were enough dammable rivers and lakes, because you can scale output up or down. When people ask about the viability of renewables they typically refer to intermittent sources.
bryanlarsen 3y ago
In the last 30 years there has never been a time where there wasn't wind or sun somewhere in Europe. So in theory it's possible to hit 100% even without storage. But obviously not in practice since it might mean you need enough generation and distribution to supply the entire continent from a tiny corner of it. (And the next night it might be a different corner). Once you add storage 100% becomes more practical, but "practical" is more a question of "how much are you willing to spend". Using the existing hydro much more heavily for storage means that 100% is practical IMO.
- sofixa 3y ago
  There have been long periods of time with low winds / overcast weather though, severely limiting the effectiveness of solar and wind power generation over weeks. https://theconversation.com/what-europes-exceptionally-low-winds-mean-for-the-future-energy-grid-170135 https://theconversation.com/what-europes-exceptionally-low-w...
belorn 3y ago
Renewable electricity production can be anything. Just because you produce something does not mean the same country has to consume it, nor that it is connected to the general grid. Renewable production can be 100% if that is what a given country is set to produce and sell on the international market. Renewable electricity consumption is a bit more tricky. People generally consume energy independently from when energy is optimally produced, so intermittent nature of renewable is a problem. There are countries which are very close to 100% renewable production but which import more than 50% of the energy that they actually consume, while at the same time being energy export positive because of massive exports during periods of optimal weather conditions.
locallost 3y ago
There is research done on this, example [1]. My feeling from listening what is said in the industry is that 80-90% will be not that hard, and that 100% will be. [1] https://twitter.com/ChristianOnRE/status/1705676813366612109 https://twitter.com/ChristianOnRE/status/1705676813366612109

Smaug123 3y ago

Well, in principle one could store solar energy in the form of a flammable fuel which can be used to rapidly spin up a turbine, by constructing ethanol/methane from carbon dioxide and water. We can't do it at scale yet, but this is the realm of e.g. Prometheus Fuels.

hn_throwaway_99 3y ago

Batteries exist (and are getting better). Most of the intermittent nature of renewables is just solving for the timing issue (e.g. evening when demand is high and the sun goes down), so short term storage is what's most in demand. Longer term storage is harder (e.g. it's cloudy for days on end), but even then there are renewable storage options like pumped hydro and generation of natural gas from electricity.

thinkcontext 3y ago

It is true the amount of storage needed goes up the higher the percentage of intermittent generation on the grid. There are various models that say it can be done but it requires overbuilding generation and substantial investment in transmission in addition to storage. It's for sure a hard problem.

dahart 3y ago

Hydro never stops. Wind and solar are cyclical, but even aside from electrical batteries, there are multiple companies designing energy storage systems (cf EnergyVault which has been making rounds in the news https://www.energyvault.com/ https://www.energyvault.com/).

worik 3y ago
> Hydro never stops It does. In droughts
- jackjeff 3y ago
  Indeed. I wonder what happens in summer in case of drought. This links partially answers my question. https://app.electricitymaps.com/zone/PT https://app.electricitymaps.com/zone/PT Apparently 33% was pumped storage (wow). And it’s a windless night so no other renewables. 17% gas that produces the CO2. That is quite impressive. Won’t compete with the crazy hydro of Norway/Sweden or the nuclear of France. But it’s quite a decent chunk of carbon free power.

generic92034 3y ago

If you are willing to build a whole lot of infrastructure for storage and accept the efficiency loss due to the conversion then you can probably get pretty close to 100%. See also: https://en.wikipedia.org/wiki/Power-to-gas https://en.wikipedia.org/wiki/Power-to-gas

worik 3y ago

Not wrong. Some renewables are consistent particularly geothermal, hydro, and biomass Geothermal is not available everywhere with current tech Hydro ditto, (must have mountains) it is hugely destructive, and is intermittent on an actual scale (dry years) Biomass is expensive and hungry for land. So it is not simple. It is doable, and essential if we are to continue lifestyles anything vaguely like what we have, but it requires careful planning and cooperation The current "Big Capital" model is not well suited. More local, small scale, and distributed generation and storage are where we need to head, IMO

matsemann 3y ago

Norway is at 98% renewable, at least.

missedthecue 3y ago
Hydro. The whole world could run off hydro if there were enough dammable rivers and lakes, because you can scale output up or down. When people ask about the viability of renewables they typically refer to intermittent sources.

bryanlarsen 3y ago

In the last 30 years there has never been a time where there wasn't wind or sun somewhere in Europe. So in theory it's possible to hit 100% even without storage. But obviously not in practice since it might mean you need enough generation and distribution to supply the entire continent from a tiny corner of it. (And the next night it might be a different corner). Once you add storage 100% becomes more practical, but "practical" is more a question of "how much are you willing to spend". Using the existing hydro much more heavily for storage means that 100% is practical IMO.

sofixa 3y ago
There have been long periods of time with low winds / overcast weather though, severely limiting the effectiveness of solar and wind power generation over weeks. https://theconversation.com/what-europes-exceptionally-low-winds-mean-for-the-future-energy-grid-170135 https://theconversation.com/what-europes-exceptionally-low-w...

belorn 3y ago

Renewable electricity production can be anything. Just because you produce something does not mean the same country has to consume it, nor that it is connected to the general grid. Renewable production can be 100% if that is what a given country is set to produce and sell on the international market. Renewable electricity consumption is a bit more tricky. People generally consume energy independently from when energy is optimally produced, so intermittent nature of renewable is a problem. There are countries which are very close to 100% renewable production but which import more than 50% of the energy that they actually consume, while at the same time being energy export positive because of massive exports during periods of optimal weather conditions.

locallost 3y ago

There is research done on this, example [1]. My feeling from listening what is said in the industry is that 80-90% will be not that hard, and that 100% will be. [1] https://twitter.com/ChristianOnRE/status/1705676813366612109 https://twitter.com/ChristianOnRE/status/1705676813366612109