8 ms·

We think that leveraging electric vehicles as a storage device will help solve the duck curve problem. Utilities are reluctant to invest billions of dollars in

by z-cam 7y ago

We think that leveraging electric vehicles as a storage device will help solve the duck curve problem. Utilities are reluctant to invest billions of dollars in energy storage to smooth out their demand curve. But consumers are already making this investment by switching en masse to EVs. We're building software that will one day help utilities transact with individual or fleet vehicle owners to leverage their vehicles as energy storage.

hn_throwaway_99 7y ago
Yeah, I'm curious if the number of "batteries" already connected to the grid could mitigate this quite a bit. For example, large industrial freezers (or perhaps even "smart" home freezers) could take their temp extra low during the day so they wouldn't need to use power during the evening. Also, with the current discrepancy in electricity costs between the day and evening, seems like this could make something like Tesla's Powerwall much more price competitive if it meant you only had to use the grid during the cheapest times.
- VyperCard 7y ago
  Yes they can. The company I work for does that using a few halls with industrial freezers.
dimitar 7y ago
Wouldn't EV increase electricity demand in the evenings when people get home and plug in their cars?
- jcrben 7y ago
  California has time of use rates (relatively new and uncommon). And we're beginning to see deep discounts in the middle of the day consistent with the solar. So people may strategically charge during the day. If it's a commuter car on a reasonable commute and you've got 300 miles of range, it's feasible to wait till midday. You can see the power supply / consumption at http://www.caiso.com/TodaysOutlook/Pages/supply.aspx http://www.caiso.com/TodaysOutlook/Pages/supply.aspx
- Filligree 7y ago
  Not if you program the cars to charge overnight. It requires more smarts, and grid interaction, but the cars could be made to obey instructions from the grid operator. There would have to be compensation, of course.
- OliverJones 7y ago
  Individual EV drjvers can set the start time for charging. It's polite to set it for sometime after midnight. This isn't fancy smart-grid stuff, just a new kind of basic common sense that will emerge as EVs get more popular.
  - catalogia 7y ago
    When pitting politeness against convenience (having the most charge in your car as is possible at any moment in time, in case you need to use it for something unanticipated), I don't have high hopes. To really incentivize this behavior properly, economic incentives need to be strong.
    - usaar333 7y ago
      The incentives are strong. My electricity is 50% more expensive before 9pm. So I set my timer (a one time setting) for then. Problem solved.
    - OliverJones 7y ago
      I used the word "politeness" because my coal-age utility (National Grid Massachusetts) doesn't offer time-of-day pricing. They seem to have no interest in doing so beyond occasional small-scale government-funded trials. If they did offer TOD pricing you bet I'd be on it. But don't underestimate the power of social pressures: "politeness". I don't throw my trash in the next street over, because to do so would be rude. The integrity of the entire Internet depends upon an altruistic TCP endpoint algorithm called "exponential backoff".
babuskov 7y ago
> But consumers are already making this investment by switching en masse to EVs "En masse"? Maybe if you live in Norway or something like that. According to the data I was able to find online, only about 2% of the new cars sold worldwide in 2018. are EVs. If we take the number of all cars currently on the roads worldwide, it's around 0.25%. As for the "Vehicle-to-grid" thing in the United States, the Wikipedia page lists 3 experiments which are in progress and 2 claims with "citation needed" flag: https://en.wikipedia.org/wiki/Vehicle-to-grid https://en.wikipedia.org/wiki/Vehicle-to-grid
- Tempest1981 7y ago
  I know we're thinking focused on cars, but fwiw: "China has 99% of the world’s 250 million electric two-wheelers."
- MiguelHudnandez 7y ago
  Most homes have multiple cars. A single high-end car could support multiple homes without the grid for over 24 hours. So I think even at adoption rates under 5% you would see enough capacity to shave those peaks and make it easier to respond to changes in demand. See Australia's tests with grid-smoothing batteries. Immensely successful and it has paid for itself. https://www.sciencealert.com/remember-the-giant-tesla-battery-in-australia-it-just-marked-its-first-year/amp https://www.sciencealert.com/remember-the-giant-tesla-batter...
- z-cam 7y ago
  I might be saying "en masse" 18 months prematurely. But at the speed utilities move, that's a blink of an eye. I'm often reminded of Steve Balmer in 2007 laughing at the iPhone: "it's $500 and it doesn't even have a keyboard!?" Less than 10 years later smartphones are ubiquitous. Not popular--ubiquitous. That's where EVs are right now: "they cost more and they can't even go 250 miles!?" EVs will be cheaper than gas cars by 2022, and a few years after that nobody will buy another gas car.
  - brandmeyer 7y ago
    $500 smartphones are only ubiquitous in the most wealthy parts of the most wealthy countries in the world.
robomartin 7y ago
> consumers are already making this investment by switching en masse to EVs I don't think we are there yet. The US fleet of electrics is in the range of about one million units. Total cars on the road is about 300 million. In other words, electrics represent 0.3% of the total fleet. That is a very long way from "en masse". Electrics, without a doubt, in some form, are the future. We all know this to be true. However, the adoption curve requires solving a bunch of problems and an expansion of the infrastructure that is also nowhere near being adequate. This translates to a simple fact: We need far more competition and far more entrants into the segment. Not announcements, but rather real vehicles you can buy. Car makers have been announcing and showing models that are vaporware for years now. I learned a long time ago that this is bad business. I used to do this kind of thing during my early days as an entrepreneur. It frustrates the customer base to no end and makes them lose trust in the company. It isn't quite lying, but it's close. I believe the inflection point will come at the intersection of a new energy storage technology (let's call it "batteries" for now) as well as the infrastructure to support it. The fires and power issues we are having in in California highlighted the weaknesses: You can't adequately charge your electrics during emergencies and range issues make them either inconvenient or just plain dangerous. I'll bet a lot of people have been made to reconsider electrics in CA precisely due to this experience. Power self-sufficiency by means of a large enough solar array at home could mitigate some of this, however, this does nothing for the person caught in an emergency away from home. We had friends who had to endure three hour trips to go get their kids after forced evacuations due to fires. When you are concerned about the safety and well-being of your loved one's, particularly kids, having range and charging issues isn't a joke at all. In fact, it's a powerful deciding factor against electrics. For context, as soon as the fires started we drove 5 minutes to the local gas station and filled-up our tanks. We got hundreds of miles of range pretty much instantly. Even better, we didn't have to think about extending that range at all, because the infrastructure is ubiquitous and available without issues outside the affected radius (and within a very small fraction of the vehicle's range). I'm not down on electrics at all. Just being realistic. It will happen when all the conditions are met and there are a dozen companies offering real products, rather than three. Lateral thought: My thinking is that the future of electric transportation will require an energy storage system based on LIQUID charging rather than plugging in. We need to be able to go into the equivalent of a gas station, pump out the spent portion of the electrolyte (or whatever) and pump in fresh "charged" electrolyte. It needs to be 5 minutes in and out for 0 to full range. I realize this might not be as "green" as people would like it to be. Not that electric cars are green at all (just wait until we have 300 million battery packs to deal with as waste). Going from 0 to full range quickly by plugging --assuming a charge storage system that could handle this-- requires very dangerous voltages and currents. I am not sure what this would look like if we had 300 million vehicles on the road with a need for that kind of energy to be delivered that quickly. I think I can say that our electrical grid is likely not designed to deliver at this rate (I haven't researched this but I have a sense this statement is likely true). Anyhow, not a simple problem. At a personal level, we were about to invest in one or two electrics by the end of the year. The fires and power outages have painted a real negative light on the practicality of these vehicles when things matter most. We'll have to rethink. No conclusion yet.
robocat 7y ago
Countries with significant lake hydroelectricity can "store" the solar power (no batteries needed) by reducing flow during the daytime (and increasing flow at nighttime if required). This is because hydroelectric dams are essentially stores of electricity. No need for pumping or other expensive storage schemes, if you already have one! This isn't mentioned in the Wikipedia article on the duck curve: I'm not sure why as it is a legitimate storage technology (just an existing one).
- erentz 7y ago
  Hydro plants are already going to be running at full output during the peak demand time when solar is not working. Just because you have solar during that day, which means you get to use less of the stored hydro water during the day, does nothing to increase the generating capacity of the hydro plant at peak time. The turbines and generators are already certain size and turn a certain speed. They don’t get bigger because you used less water at midday. So to make hydro work as a storage solution you need to build more hydro than what you currently have already to replace fossil generation and make sure you can meet all your evening demand. That is absolutely not going to happen anymore, in developed countries hydro is well tapped and nobody wants more dams or lakes. In developing countries there may be some potential but it won’t meet all demand. There needs to be another storage solution for solar to become viable in this way.
  - robocat 7y ago
    > Hydro plants are going to be running at full output during the peak demand time when solar is not working. How do you know that? During drought periods surely it's not true (if there's not enough water to run them). The flow of rivers is controlled to some extent (which may prevent saving during the day and generating in evening). And presumably it might be true in one country, but not another, depending on a raft of factors. I'm guessing there is data somewhere showing utilisation of hydro during evening.
    - erentz 7y ago
      Part of it is based on previous experience working for the national grid in a hydro rich 80-90% clean generating country. I can’t speak specifically for the US but think about it like this. You need to have enough generating capacity on your grid to meet the peak demand. Which according to this duck graph is when solar is not generating. But we have not overbuilt capacity by some large margin. And hydro is only some portion of that total capacity today. The rest is coal, nuclear, increasingly gas, and some small amount of renewables. Therefore how can hydro alone meet the all of the demand when you remove the goal, gas, etc.
Reedx 7y ago
Or we could just stop kidding ourselves. As Bill Gates and others who've done the math have repeatedly said[1], there is no storage solution anywhere on the horizon. Batteries are orders of magnitude too expensive. You have to consider the problem holistically. Steel and concrete production. Places like Tokyo that go days without power. Countries like India that are not going to pay a premium. If you're concerned about climate change, please take a serious look at nuclear energy[2][3][4]. 1. https://youtu.be/d1EB1zsxW0k?t=520 https://youtu.be/d1EB1zsxW0k?t=520 2. https://www.gatesnotes.com/About-Bill-Gates/Year-in-Review-2018 https://www.gatesnotes.com/About-Bill-Gates/Year-in-Review-2... 3. https://ourworldindata.org/what-is-the-safest-form-of-energy https://ourworldindata.org/what-is-the-safest-form-of-energy 4. https://www.forbes.com/sites/michaelshellenberger/2019/02/05/if-saving-the-climate-requires-making-energy-so-expensive-why-is-french-electricity-so-cheap/ https://www.forbes.com/sites/michaelshellenberger/2019/02/05...
- yorwba 7y ago
  According to the U.S. Energy Information administration, nuclear is more expensive than battery storage: https://www.eia.gov/outlooks/aeo/assumptions/pdf/table_8.2.pdf https://www.eia.gov/outlooks/aeo/assumptions/pdf/table_8.2.p...
  - acidburnNSA 7y ago
    Nuclear builds in the west right now have been boondoggles; the nuclear industry must regain its ability to build effectively to play a role here. This has been done before through standardization of design and serialization of production. This could conceivably be scaled back up if we were serious about decarbonization, with high likelihood of success given previous successes (e.g. France decarbonized 80% of its electricity grid in 15 years by building 58 standardized nuclear plants). Current prices for variable renewables and batteries are mostly on the current margin. Everyone agrees that costs of variable sources skyrocket as penetration increases due to curtailment and overbuilding. When you get 100% of your electricity on a sunny day (including from storage through the night) from solar, the next solar plant you build will have to be curtailed. Seasonal and crazy-weather variations are much harder and more expensive to fill with variable sources than the daily fluctuations. These lowlow prices we see headlines about today are about building renewables in a world alongside hilariously cheap fracked natural gas plants that can pick up the slack. There's good info along these lines in here: https://www.nrel.gov/docs/fy16osti/66970.pdf https://www.nrel.gov/docs/fy16osti/66970.pdf Nuclear is unique in that it's the only low-carbon energy source that can run 24/7 for years at a time (followed by a month outage, then 2 more years, etc.). Hydro can kind of do this in certain geographies, but is very hard to scale to the point we need. Nuclear also uses far less land and raw materials than the variable renewables, especially when chemical battery storage is included. But yeah unless nuclear folks can get costs back down soon, no one is going to be interested. If in the end variable stuff is indeed hard at massive scale (I strongly believe this will be the case), then if we don't have nuclear, fracked and high-carbon natural gas and oil (for transportation) will be around at 50% of our total energy for a long time.
HALtheWise 7y ago
This seems like the sort of claim that can only be checked with math, not intuition. Without further ado: https://colab.research.google.com/drive/1fcwuNd2XANIXmKGPRN_2GedCWzVSLzoZ https://colab.research.google.com/drive/1fcwuNd2XANIXmKGPRN_... Basically, I got some raw data by tracing the graph in Wikipedia[0], as well as the current amount of hydroelectricity generated per day. I made the (highly pessimistic) assumption that aside from hydro, solar would be the sole energy supply for the grid by scaling the production numbers in the graph until the area under the solar curve matched the area under the total, minus the production of hydro. I don't actually know that anybody is seriously advocating for pure solar + hydro, but I wanted to run the numbers. The result, assuming cars with 85kWh batteries that can be 70% available for grid balancing (leaving ~80-100 miles of range for driving and such) is that California would need 4.3 million cars acting as grid balancing. For reference, that is just under 30% of the number of cars currently in California, where electrics made up 7% of new car sales last year. Ultimately, I think the bigger problem is battery degradation, not battery capacity. Being used this heavily for grid balancing would at least double total battery usage on a car, and apart from Tesla with their million-mile drivetrain, no other manufacturer seems to be over-designing their batteries enough to support that. Perhaps that will change if the economics of feeding power back into the grid become compelling enough. [0]: https://apps.automeris.io/wpd/ https://apps.automeris.io/wpd/
oh_sigh 7y ago
Let's I have an all electric car and sign up for your program. How would I calculate the cost to me of the shortened lifespan of my batteries? Would the manufacturer honor their warranty if I used the car for not only driving but also as part of a battery bank?

by z-cam 7y ago

hn_throwaway_99 7y ago

Yeah, I'm curious if the number of "batteries" already connected to the grid could mitigate this quite a bit. For example, large industrial freezers (or perhaps even "smart" home freezers) could take their temp extra low during the day so they wouldn't need to use power during the evening. Also, with the current discrepancy in electricity costs between the day and evening, seems like this could make something like Tesla's Powerwall much more price competitive if it meant you only had to use the grid during the cheapest times.

VyperCard 7y ago
Yes they can. The company I work for does that using a few halls with industrial freezers.

dimitar 7y ago

Wouldn't EV increase electricity demand in the evenings when people get home and plug in their cars?

jcrben 7y ago
California has time of use rates (relatively new and uncommon). And we're beginning to see deep discounts in the middle of the day consistent with the solar. So people may strategically charge during the day. If it's a commuter car on a reasonable commute and you've got 300 miles of range, it's feasible to wait till midday. You can see the power supply / consumption at http://www.caiso.com/TodaysOutlook/Pages/supply.aspx http://www.caiso.com/TodaysOutlook/Pages/supply.aspx
Filligree 7y ago
Not if you program the cars to charge overnight. It requires more smarts, and grid interaction, but the cars could be made to obey instructions from the grid operator. There would have to be compensation, of course.
OliverJones 7y ago
Individual EV drjvers can set the start time for charging. It's polite to set it for sometime after midnight. This isn't fancy smart-grid stuff, just a new kind of basic common sense that will emerge as EVs get more popular.
- catalogia 7y ago
  When pitting politeness against convenience (having the most charge in your car as is possible at any moment in time, in case you need to use it for something unanticipated), I don't have high hopes. To really incentivize this behavior properly, economic incentives need to be strong.
  - usaar333 7y ago
    The incentives are strong. My electricity is 50% more expensive before 9pm. So I set my timer (a one time setting) for then. Problem solved.
  - OliverJones 7y ago
    I used the word "politeness" because my coal-age utility (National Grid Massachusetts) doesn't offer time-of-day pricing. They seem to have no interest in doing so beyond occasional small-scale government-funded trials. If they did offer TOD pricing you bet I'd be on it. But don't underestimate the power of social pressures: "politeness". I don't throw my trash in the next street over, because to do so would be rude. The integrity of the entire Internet depends upon an altruistic TCP endpoint algorithm called "exponential backoff".

babuskov 7y ago

> But consumers are already making this investment by switching en masse to EVs "En masse"? Maybe if you live in Norway or something like that. According to the data I was able to find online, only about 2% of the new cars sold worldwide in 2018. are EVs. If we take the number of all cars currently on the roads worldwide, it's around 0.25%. As for the "Vehicle-to-grid" thing in the United States, the Wikipedia page lists 3 experiments which are in progress and 2 claims with "citation needed" flag: https://en.wikipedia.org/wiki/Vehicle-to-grid https://en.wikipedia.org/wiki/Vehicle-to-grid

Tempest1981 7y ago
I know we're thinking focused on cars, but fwiw: "China has 99% of the world’s 250 million electric two-wheelers."
MiguelHudnandez 7y ago
Most homes have multiple cars. A single high-end car could support multiple homes without the grid for over 24 hours. So I think even at adoption rates under 5% you would see enough capacity to shave those peaks and make it easier to respond to changes in demand. See Australia's tests with grid-smoothing batteries. Immensely successful and it has paid for itself. https://www.sciencealert.com/remember-the-giant-tesla-battery-in-australia-it-just-marked-its-first-year/amp https://www.sciencealert.com/remember-the-giant-tesla-batter...
z-cam 7y ago
I might be saying "en masse" 18 months prematurely. But at the speed utilities move, that's a blink of an eye. I'm often reminded of Steve Balmer in 2007 laughing at the iPhone: "it's $500 and it doesn't even have a keyboard!?" Less than 10 years later smartphones are ubiquitous. Not popular--ubiquitous. That's where EVs are right now: "they cost more and they can't even go 250 miles!?" EVs will be cheaper than gas cars by 2022, and a few years after that nobody will buy another gas car.
- brandmeyer 7y ago
  $500 smartphones are only ubiquitous in the most wealthy parts of the most wealthy countries in the world.

robomartin 7y ago

> consumers are already making this investment by switching en masse to EVs I don't think we are there yet. The US fleet of electrics is in the range of about one million units. Total cars on the road is about 300 million. In other words, electrics represent 0.3% of the total fleet. That is a very long way from "en masse". Electrics, without a doubt, in some form, are the future. We all know this to be true. However, the adoption curve requires solving a bunch of problems and an expansion of the infrastructure that is also nowhere near being adequate. This translates to a simple fact: We need far more competition and far more entrants into the segment. Not announcements, but rather real vehicles you can buy. Car makers have been announcing and showing models that are vaporware for years now. I learned a long time ago that this is bad business. I used to do this kind of thing during my early days as an entrepreneur. It frustrates the customer base to no end and makes them lose trust in the company. It isn't quite lying, but it's close. I believe the inflection point will come at the intersection of a new energy storage technology (let's call it "batteries" for now) as well as the infrastructure to support it. The fires and power issues we are having in in California highlighted the weaknesses: You can't adequately charge your electrics during emergencies and range issues make them either inconvenient or just plain dangerous. I'll bet a lot of people have been made to reconsider electrics in CA precisely due to this experience. Power self-sufficiency by means of a large enough solar array at home could mitigate some of this, however, this does nothing for the person caught in an emergency away from home. We had friends who had to endure three hour trips to go get their kids after forced evacuations due to fires. When you are concerned about the safety and well-being of your loved one's, particularly kids, having range and charging issues isn't a joke at all. In fact, it's a powerful deciding factor against electrics. For context, as soon as the fires started we drove 5 minutes to the local gas station and filled-up our tanks. We got hundreds of miles of range pretty much instantly. Even better, we didn't have to think about extending that range at all, because the infrastructure is ubiquitous and available without issues outside the affected radius (and within a very small fraction of the vehicle's range). I'm not down on electrics at all. Just being realistic. It will happen when all the conditions are met and there are a dozen companies offering real products, rather than three. Lateral thought: My thinking is that the future of electric transportation will require an energy storage system based on LIQUID charging rather than plugging in. We need to be able to go into the equivalent of a gas station, pump out the spent portion of the electrolyte (or whatever) and pump in fresh "charged" electrolyte. It needs to be 5 minutes in and out for 0 to full range. I realize this might not be as "green" as people would like it to be. Not that electric cars are green at all (just wait until we have 300 million battery packs to deal with as waste). Going from 0 to full range quickly by plugging --assuming a charge storage system that could handle this-- requires very dangerous voltages and currents. I am not sure what this would look like if we had 300 million vehicles on the road with a need for that kind of energy to be delivered that quickly. I think I can say that our electrical grid is likely not designed to deliver at this rate (I haven't researched this but I have a sense this statement is likely true). Anyhow, not a simple problem. At a personal level, we were about to invest in one or two electrics by the end of the year. The fires and power outages have painted a real negative light on the practicality of these vehicles when things matter most. We'll have to rethink. No conclusion yet.

robocat 7y ago

Countries with significant lake hydroelectricity can "store" the solar power (no batteries needed) by reducing flow during the daytime (and increasing flow at nighttime if required). This is because hydroelectric dams are essentially stores of electricity. No need for pumping or other expensive storage schemes, if you already have one! This isn't mentioned in the Wikipedia article on the duck curve: I'm not sure why as it is a legitimate storage technology (just an existing one).

erentz 7y ago
Hydro plants are already going to be running at full output during the peak demand time when solar is not working. Just because you have solar during that day, which means you get to use less of the stored hydro water during the day, does nothing to increase the generating capacity of the hydro plant at peak time. The turbines and generators are already certain size and turn a certain speed. They don’t get bigger because you used less water at midday. So to make hydro work as a storage solution you need to build more hydro than what you currently have already to replace fossil generation and make sure you can meet all your evening demand. That is absolutely not going to happen anymore, in developed countries hydro is well tapped and nobody wants more dams or lakes. In developing countries there may be some potential but it won’t meet all demand. There needs to be another storage solution for solar to become viable in this way.
- robocat 7y ago
  > Hydro plants are going to be running at full output during the peak demand time when solar is not working. How do you know that? During drought periods surely it's not true (if there's not enough water to run them). The flow of rivers is controlled to some extent (which may prevent saving during the day and generating in evening). And presumably it might be true in one country, but not another, depending on a raft of factors. I'm guessing there is data somewhere showing utilisation of hydro during evening.
  - erentz 7y ago
    Part of it is based on previous experience working for the national grid in a hydro rich 80-90% clean generating country. I can’t speak specifically for the US but think about it like this. You need to have enough generating capacity on your grid to meet the peak demand. Which according to this duck graph is when solar is not generating. But we have not overbuilt capacity by some large margin. And hydro is only some portion of that total capacity today. The rest is coal, nuclear, increasingly gas, and some small amount of renewables. Therefore how can hydro alone meet the all of the demand when you remove the goal, gas, etc.

Reedx 7y ago

Or we could just stop kidding ourselves. As Bill Gates and others who've done the math have repeatedly said[1], there is no storage solution anywhere on the horizon. Batteries are orders of magnitude too expensive. You have to consider the problem holistically. Steel and concrete production. Places like Tokyo that go days without power. Countries like India that are not going to pay a premium. If you're concerned about climate change, please take a serious look at nuclear energy[2][3][4]. 1. https://youtu.be/d1EB1zsxW0k?t=520 https://youtu.be/d1EB1zsxW0k?t=520 2. https://www.gatesnotes.com/About-Bill-Gates/Year-in-Review-2018 https://www.gatesnotes.com/About-Bill-Gates/Year-in-Review-2... 3. https://ourworldindata.org/what-is-the-safest-form-of-energy https://ourworldindata.org/what-is-the-safest-form-of-energy 4. https://www.forbes.com/sites/michaelshellenberger/2019/02/05/if-saving-the-climate-requires-making-energy-so-expensive-why-is-french-electricity-so-cheap/ https://www.forbes.com/sites/michaelshellenberger/2019/02/05...

yorwba 7y ago
According to the U.S. Energy Information administration, nuclear is more expensive than battery storage: https://www.eia.gov/outlooks/aeo/assumptions/pdf/table_8.2.pdf https://www.eia.gov/outlooks/aeo/assumptions/pdf/table_8.2.p...
- acidburnNSA 7y ago
  Nuclear builds in the west right now have been boondoggles; the nuclear industry must regain its ability to build effectively to play a role here. This has been done before through standardization of design and serialization of production. This could conceivably be scaled back up if we were serious about decarbonization, with high likelihood of success given previous successes (e.g. France decarbonized 80% of its electricity grid in 15 years by building 58 standardized nuclear plants). Current prices for variable renewables and batteries are mostly on the current margin. Everyone agrees that costs of variable sources skyrocket as penetration increases due to curtailment and overbuilding. When you get 100% of your electricity on a sunny day (including from storage through the night) from solar, the next solar plant you build will have to be curtailed. Seasonal and crazy-weather variations are much harder and more expensive to fill with variable sources than the daily fluctuations. These lowlow prices we see headlines about today are about building renewables in a world alongside hilariously cheap fracked natural gas plants that can pick up the slack. There's good info along these lines in here: https://www.nrel.gov/docs/fy16osti/66970.pdf https://www.nrel.gov/docs/fy16osti/66970.pdf Nuclear is unique in that it's the only low-carbon energy source that can run 24/7 for years at a time (followed by a month outage, then 2 more years, etc.). Hydro can kind of do this in certain geographies, but is very hard to scale to the point we need. Nuclear also uses far less land and raw materials than the variable renewables, especially when chemical battery storage is included. But yeah unless nuclear folks can get costs back down soon, no one is going to be interested. If in the end variable stuff is indeed hard at massive scale (I strongly believe this will be the case), then if we don't have nuclear, fracked and high-carbon natural gas and oil (for transportation) will be around at 50% of our total energy for a long time.

HALtheWise 7y ago

This seems like the sort of claim that can only be checked with math, not intuition. Without further ado: https://colab.research.google.com/drive/1fcwuNd2XANIXmKGPRN_2GedCWzVSLzoZ https://colab.research.google.com/drive/1fcwuNd2XANIXmKGPRN_... Basically, I got some raw data by tracing the graph in Wikipedia[0], as well as the current amount of hydroelectricity generated per day. I made the (highly pessimistic) assumption that aside from hydro, solar would be the sole energy supply for the grid by scaling the production numbers in the graph until the area under the solar curve matched the area under the total, minus the production of hydro. I don't actually know that anybody is seriously advocating for pure solar + hydro, but I wanted to run the numbers. The result, assuming cars with 85kWh batteries that can be 70% available for grid balancing (leaving ~80-100 miles of range for driving and such) is that California would need 4.3 million cars acting as grid balancing. For reference, that is just under 30% of the number of cars currently in California, where electrics made up 7% of new car sales last year. Ultimately, I think the bigger problem is battery degradation, not battery capacity. Being used this heavily for grid balancing would at least double total battery usage on a car, and apart from Tesla with their million-mile drivetrain, no other manufacturer seems to be over-designing their batteries enough to support that. Perhaps that will change if the economics of feeding power back into the grid become compelling enough. [0]: https://apps.automeris.io/wpd/ https://apps.automeris.io/wpd/

oh_sigh 7y ago

Let's I have an all electric car and sign up for your program. How would I calculate the cost to me of the shortened lifespan of my batteries? Would the manufacturer honor their warranty if I used the car for not only driving but also as part of a battery bank?