7 ms·

The US grid battery fleet is about to double – again

47 points by mfiguiere 3y ago

mathgradthrow 3y ago
Gigawatts are not a unit of energy.... something something zalgo.
- audunw 3y ago
  Installed capacity is sometimes measured by power output rather than energy storage capacity. Both measures are relevant.
  - XorNot 3y ago
    And yet only one is ever mentioned when batteries come up, despite the context being heavily implied to be "energy" not "power".
    - Ekaros 3y ago
      I always find talk of power weird. It does make sense when you need to replace some plant going down... But in general storage capacity is much more important. That is how many hours and at what price can they provide demand for. With hours here being some reasonable number above say four...
    - cycomanic 3y ago
      What I've seen in several articles is that peak power production seems to be as much a limiting factor as stored energy. I'm still haven't found a good explanation why that is though. So if anyone could educate me, I'm all ears.
      - tsimionescu 3y ago
        Let's take an absurd extreme case to illustrate - if you had a battery that could store 1GWh but could only discharge up to 1mW in an hour, how would you power an aluminum furnace with this battery? Assuming you are using batteries for continuous solar power, you basically need the batteries to be able to store enough power to last through the night, and to be able to match the solar power plant's peak power - otherwise, the grid can't power the same things during the night that it can during the day, which was the whole reason we wanted the batteries in the first place.
      - Gare 3y ago
        Because grid batteries are currently used as peak supply - if a production of power plants suddenly falls of by 10 GW or there is 10 GW additional demand, you have to quickly provide that 10 GW of power before other (cheaper) additional production can be ramped up.
      - Gibbon1 3y ago
        My suspicion is battery life estimating is complicated and proprietary. So your depreciation due to wear depends on both the rate of charge and the rate of discharge. My best guess is they shoot for a discharge rate of roughly C3. Meaning they can deliver the rated power for 3 hours. Suspect they keep the charge between 10 and 90%. So I think you can multiply watts by 4 to get watt-hours. That said I've looked for actual numbers in kwh and not found much.
    - ViewTrick1002 3y ago
      Depends on who you ask. For the grid operators since they balance instantaneous supply and demand they only care about power available. Expecting the producers to maximize their profit and hence save the batteries until they are most needed. When explicitly designing an electrical system, say an off-grid cabin, both the energy stored and instantaneous matching of supply needs to pencil out. In the large scale grid example we expect the market to handle the energy balance. Adding transmission links, secondary markets and so on when the market does not adequately match demand. Generally speaking today batteries used for grid scale storage store 4 GWh per 1 GW. This number comes from maximizing the utilization of the grid connection and matching the hours per day with highest electricity rates.
  - jillesvangurp 3y ago
    Exactly, especially with some types of batteries this is relevant. Redox flow batteries that are being experimented with for grid storage now use a reservoir for storing the anolyte and catolyte fluids. The bit that allows those to interface where the power is generated is much smaller though. So you can take the same battery and trivially double or triple the storage capacity by simply using bigger reservoirs and more liquid but the power delivery would stay the same. These types of battery are potentially great for longer term storage but they aren't necessarily able to deliver the stored energy quickly. It could take days/weeks to deplete them and a similar amount of time to charge them back up. Lithium ion grid batteries are sort of the opposite. They can deliver a lot of power but usually only for a few hours at maximum capacity until they are depleted. So, you see companies install a few hundred gwh of capacity being able to deliver most of that power in a few hours.
- renewiltord 3y ago
  They’re a unit of power which is what is being described here. People want to know how much they can draw per unit time from each source. Wind Turbines a GW Nuclear Plant b GW Battery Storage c GW That’s a power measure so you use power units. It would make no sense to use energy units.
- shatnersbassoon 3y ago
  It's presented in Gigawatts here, but I expect the actual metric is probably something like "Gigawatts available for 99th centile of duration of demand peaks", as this would allow you to talk about capacity in the same units as grid supply and demand. The whole point of grid batteries is for near-instant availability, so total energy available is moot if you can't access it right away - therefore a metric of energy would be less useful. Anyway, that's my speculation.
hulitu 3y ago
> The US grid battery fleet is about to double – again So they now have two. /s
Animats 3y ago
It's easy to explain to finance people. It's a form of commodity speculation. Storage is a buy-low, sell-high business, with a daily cycle. This expansion will continue until peak and valley prices start to level out.
- JumpCrisscross 3y ago
  > easy to explain to finance people. It's a form of commodity speculation Energy trades unlike any other commodity due to its perishability. There is nothing easy about trading power, though if someone has a background in derivatives, that helps. (They're also irregularly perishable.) For the lay person, I'd recommend smarting up on Fabozzi's Fixed Income before trying to explain anything to anyone about trading power.
- legulere 3y ago
  There is significant cost in storage though, so there will still be peaks and valleys.
wolverine876 3y ago
How long does the typical battery last before it needs significant new investment (major maintenance or replacement)? In other words, how long before we need to install another 30 GW not to increase capacity, but to maintain it? I'm not a pessimist but I know that at this stage in an adoption cycle, it's all gain, but that's not the long-term reality. I'm wondering what the long-term looks like. In part, if the capacity keeps doubling, replacing 30 GW will be trivial compared to the new capacity. But eventually that will flatten out.
- rpmisms 3y ago
  I don't know the actual numbers on that, but I do know that stationary storage lasts much longer than e.g. EV batteries, since there are no weight restrictions, so they're cycled more gently, temps are better, they can be kept in a more optimal window, you can use things like LFP that are heavier, and BMS has more latitude with more cells to work with.
- The_Colonel 3y ago
  Tesla Megapacks come with a 15-year "no defect" and "energy retention" warranty. A 10 or 20 year "performance guarantee" is available for an additional cost. (an example of Li-Ion based storage, I assume it won't differ wildly with other producers) I think they can in principle last longer if used well. You can control the temperature, you can use weather forecast (as part of some network-wide forecast of future required capacity) to decide how much you should charge the batteries. You'd use the "unhealthy" charging/discharging only in extreme situations, while in the day-to-day cycles you'd keep the batteries within the healthy voltage range.
  - adrianN 3y ago
    We will probably also switch to different chemistries for grid batteries. Sodium batteries for example are cheaper. Iron oxide is also interesting.
  - gwd 3y ago
    Two years ago when I was considering installing a battery along with my solar panels, here was the estimations I did: 1. Additional cost of installing a 13.5kWh Tesla Powerwall was quoted as being around £12,000 2. Warranty was 80% capacity after 10 years Now, my experience with batteries in general is that once they start to go, they deteriorate pretty rapidly; so 80% after 10 years to me basically account 10 years as the lifetime of the battery. £12k for 10 years is £1.2k per year, or £100 per month: that is, the battery would have to allow me to save £100/month in electricity just to break even -- and that's before factoring in the cost of capital (i.e., if I take that £12k and invested it somewhere else, I'd have a lot more than £12k after 10 years). Even if the batteries managed to eke out a reasonable capacity for 20 years -- which seems pretty unlikely to me -- I'd still have to somehow save £50/month to break even. All in all the battery just didn't make financial sense for me as an individual. One expects that the companies doing this on an industrial scale have done the math and managed to find some economies of scale that make it profitable; but it's not out of the realm of possibility that due to a combination of optimism, overselling on the part of battery companies, and FOMO, that they've drastically overestimated the performance of their batteries, and are going to find 15 years down the road that they're beginning to fail without having paid back the capital investment used to buy them.
ChatGTP 3y ago
Anyone else starting to get the feeling that the idea of "base load" power was a scam ? By "base load" I mean the insurmountable blocker for renewable adoption. The storage industry has already proven it can basically double national installed capacity from one year to the next: It did so in 2023 and 2022, and in 2021 it more than tripled the previous year’s tally. The continuation of this trend just gets more impressive with time: A few years ago, doubling storage capacity only meant building 1 gigawatt. Now, the industry is looking at adding 14 gigawatts in a year, requiring an unprecedented amount of work at project sites around the country. It's hard to believe how quickly the renewable revolution is happening. The rise of AI? What about the rise of renewables, holy hell. I was browsing panels the other day for my upcoming project to convert our entire house to solar (we only bought last year, it's top priority for me, for my children's future) and I cannot believe that I can buy top of the range 550W panels for about $200USD per panel, like, my electricity bill is about $400 a month. It's totally ridiculous. I cannot believe people more people haven't caught onto this. I'll be able to pay off the whole system, including batteries in about two year's worth of electricity bills, granted I'm mostly installing myself, it's wild.
- otherme123 3y ago
  I've been in your boots for 15 years, and I barely convinced anyone. Even my thermal panels are viewed with suspiction, and people don't believe me when I told them my hot water come from them with a little help from an electric heater in the winter. They pay themselves once per year, easily. Frustratingly, the more common doubt is "if it's so good, how are there so few people doing it?" At this point I gave up. I enjoy my free electricity, and even earn some money, but quietly. A pending change in households is going 24/48V DC. The inverters are costly, and they feel stupid when you know a lot of appliances have an AC/DC transformer to undo what your $3K inverters are doing 10 meters away, losing maybe 20% in the process.
  - ChatGTP 3y ago
    Frustratingly, the more common doubt is "if it's so good, how are there so few people doing it?" Do you think that 15 years back it was prohibitive from a cost perspective now? Was it always this economically viable? I mean ~ $200 a panel, it's a true no brainer, maybe the initial outlay was a little too much for people way back when? On the other hand, I guess with peaking electricity prices in many parts of the world, it would've easily paid itself off by now for most people.
rapsey 3y ago
Are there other players other than Tesla making these?
- DoingIsLearning 3y ago
  BYD, Hitachi, Siemens (energy).
dappermanneke 3y ago
a doubling of barely anything is still barely anything
- Y-bar 3y ago
  Let's play chess. If I win, you send me some rice, ok?
  - fbdab103 3y ago
    In case anyone is unfamiliar: https://www.dr-mikes-math-games-for-kids.com/rice-and-chessboard.html https://www.dr-mikes-math-games-for-kids.com/rice-and-chessb... "Oh emperor, my wishes are simple. I only wish for this. Give me one grain of rice for the first square of the chessboard, two grains for the next square, four for the next, eight for the next and so on for all 64 squares, with each square having double the number of grains as the square before." The emperor agreed, amazed that the man had asked for such a small reward - or so he thought. After a week, his treasurer came back and informed him that the reward would add up to an astronomical sum, far greater than all the rice that could conceivably be produced in many many centuries!
  - dappermanneke 3y ago
    against what timeframe are you betting a load of money on batteries displacing all fossil fuels
  - kgabis 3y ago
    Can the number of grains follow an S-curve?
    - Y-bar 3y ago
      A number of grains can apparently follow many different curves: http://foodfont.com/rice/ http://foodfont.com/rice/
modeless 3y ago
Doubling in 2024 is great but the estimate for 2025 is nowhere near doubling again. How many doublings will we need to store enough energy that solar can replace all non-renewables? I imagine it's still a lot. Edit: this page claims we need 84 times what we had in 2022, the estimate for 2024 is ~3x higher, so call it ~5 more doublings after this year. https://www.alsym.com/blog/how-much-energy-storage-do-we-need-for-a-completely-clean-u-s-electric-grid/ https://www.alsym.com/blog/how-much-energy-storage-do-we-nee...
- colechristensen 3y ago
  The opposite needs to happen, industry needs to adjust to taking advantage of regular daily energy price swings. Plenty of industries can. Instantaneous pricing for electricity motivates people and industry to make better choices. Very cheap energy will enable interesting things too.
  - adrianN 3y ago
    Realistically both things will need to happen. There is a lot of demand that can’t be time shifted by more than a few hours. We need storage for a few weeks of consumption eventually.
  - ssl-3 3y ago
    Indeed. As a consumer in Ohio, variable-rate pricing kind of scares me: It's nice to be able to run the clothes dryer without any concern over what time of day it is. We don't do variable-rate pricing here (at least for residential users). But I'd manage to sort it out in pretty short order, I think: It usually isn't very important to me what time of day the clothes get dried (as long as they don't sit long enough to get stinky), so I would indeed be motivated to pay attention to that. I, myself, would even become motivated to automate it so that the clothes begin drying automatically when energy is [relatively] cheap. I can also imagine things like automating water heating: Burn Joules when it is cheap to do so, and store [most of] them for later use at a time that may be more convenient to me. (The math gets interesting on this one.) Having very cheap energy be available occasionally would also be neat: I've got computationally-intensive tasks that need to get done some day. These cost real money to run on the hardware that I have. It sure would be nice if I could save some money by only doing these tasks when power is cheaper. (Right now, I do try to optimize timing them for energy efficiency. For instance, in the summer it is cheaper to run them on cool nights when the windows might be open than during a hot, sunny day when the aircon might barely be keeping up.)
deleted 3y ago
[deleted]

47 points by mfiguiere 3y ago

mathgradthrow 3y ago

Gigawatts are not a unit of energy.... something something zalgo.

audunw 3y ago
Installed capacity is sometimes measured by power output rather than energy storage capacity. Both measures are relevant.
- XorNot 3y ago
  And yet only one is ever mentioned when batteries come up, despite the context being heavily implied to be "energy" not "power".
  - Ekaros 3y ago
    I always find talk of power weird. It does make sense when you need to replace some plant going down... But in general storage capacity is much more important. That is how many hours and at what price can they provide demand for. With hours here being some reasonable number above say four...
  - cycomanic 3y ago
    What I've seen in several articles is that peak power production seems to be as much a limiting factor as stored energy. I'm still haven't found a good explanation why that is though. So if anyone could educate me, I'm all ears.
    - tsimionescu 3y ago
      Let's take an absurd extreme case to illustrate - if you had a battery that could store 1GWh but could only discharge up to 1mW in an hour, how would you power an aluminum furnace with this battery? Assuming you are using batteries for continuous solar power, you basically need the batteries to be able to store enough power to last through the night, and to be able to match the solar power plant's peak power - otherwise, the grid can't power the same things during the night that it can during the day, which was the whole reason we wanted the batteries in the first place.
    - Gare 3y ago
      Because grid batteries are currently used as peak supply - if a production of power plants suddenly falls of by 10 GW or there is 10 GW additional demand, you have to quickly provide that 10 GW of power before other (cheaper) additional production can be ramped up.
    - Gibbon1 3y ago
      My suspicion is battery life estimating is complicated and proprietary. So your depreciation due to wear depends on both the rate of charge and the rate of discharge. My best guess is they shoot for a discharge rate of roughly C3. Meaning they can deliver the rated power for 3 hours. Suspect they keep the charge between 10 and 90%. So I think you can multiply watts by 4 to get watt-hours. That said I've looked for actual numbers in kwh and not found much.
  - ViewTrick1002 3y ago
    Depends on who you ask. For the grid operators since they balance instantaneous supply and demand they only care about power available. Expecting the producers to maximize their profit and hence save the batteries until they are most needed. When explicitly designing an electrical system, say an off-grid cabin, both the energy stored and instantaneous matching of supply needs to pencil out. In the large scale grid example we expect the market to handle the energy balance. Adding transmission links, secondary markets and so on when the market does not adequately match demand. Generally speaking today batteries used for grid scale storage store 4 GWh per 1 GW. This number comes from maximizing the utilization of the grid connection and matching the hours per day with highest electricity rates.
- jillesvangurp 3y ago
  Exactly, especially with some types of batteries this is relevant. Redox flow batteries that are being experimented with for grid storage now use a reservoir for storing the anolyte and catolyte fluids. The bit that allows those to interface where the power is generated is much smaller though. So you can take the same battery and trivially double or triple the storage capacity by simply using bigger reservoirs and more liquid but the power delivery would stay the same. These types of battery are potentially great for longer term storage but they aren't necessarily able to deliver the stored energy quickly. It could take days/weeks to deplete them and a similar amount of time to charge them back up. Lithium ion grid batteries are sort of the opposite. They can deliver a lot of power but usually only for a few hours at maximum capacity until they are depleted. So, you see companies install a few hundred gwh of capacity being able to deliver most of that power in a few hours.
renewiltord 3y ago
They’re a unit of power which is what is being described here. People want to know how much they can draw per unit time from each source. Wind Turbines a GW Nuclear Plant b GW Battery Storage c GW That’s a power measure so you use power units. It would make no sense to use energy units.
shatnersbassoon 3y ago
It's presented in Gigawatts here, but I expect the actual metric is probably something like "Gigawatts available for 99th centile of duration of demand peaks", as this would allow you to talk about capacity in the same units as grid supply and demand. The whole point of grid batteries is for near-instant availability, so total energy available is moot if you can't access it right away - therefore a metric of energy would be less useful. Anyway, that's my speculation.

hulitu 3y ago

> The US grid battery fleet is about to double – again So they now have two. /s

Animats 3y ago

It's easy to explain to finance people. It's a form of commodity speculation. Storage is a buy-low, sell-high business, with a daily cycle. This expansion will continue until peak and valley prices start to level out.

JumpCrisscross 3y ago
> easy to explain to finance people. It's a form of commodity speculation Energy trades unlike any other commodity due to its perishability. There is nothing easy about trading power, though if someone has a background in derivatives, that helps. (They're also irregularly perishable.) For the lay person, I'd recommend smarting up on Fabozzi's Fixed Income before trying to explain anything to anyone about trading power.
legulere 3y ago
There is significant cost in storage though, so there will still be peaks and valleys.

wolverine876 3y ago

How long does the typical battery last before it needs significant new investment (major maintenance or replacement)? In other words, how long before we need to install another 30 GW not to increase capacity, but to maintain it? I'm not a pessimist but I know that at this stage in an adoption cycle, it's all gain, but that's not the long-term reality. I'm wondering what the long-term looks like. In part, if the capacity keeps doubling, replacing 30 GW will be trivial compared to the new capacity. But eventually that will flatten out.

rpmisms 3y ago
I don't know the actual numbers on that, but I do know that stationary storage lasts much longer than e.g. EV batteries, since there are no weight restrictions, so they're cycled more gently, temps are better, they can be kept in a more optimal window, you can use things like LFP that are heavier, and BMS has more latitude with more cells to work with.
The_Colonel 3y ago
Tesla Megapacks come with a 15-year "no defect" and "energy retention" warranty. A 10 or 20 year "performance guarantee" is available for an additional cost. (an example of Li-Ion based storage, I assume it won't differ wildly with other producers) I think they can in principle last longer if used well. You can control the temperature, you can use weather forecast (as part of some network-wide forecast of future required capacity) to decide how much you should charge the batteries. You'd use the "unhealthy" charging/discharging only in extreme situations, while in the day-to-day cycles you'd keep the batteries within the healthy voltage range.
- adrianN 3y ago
  We will probably also switch to different chemistries for grid batteries. Sodium batteries for example are cheaper. Iron oxide is also interesting.
- gwd 3y ago
  Two years ago when I was considering installing a battery along with my solar panels, here was the estimations I did: 1. Additional cost of installing a 13.5kWh Tesla Powerwall was quoted as being around £12,000 2. Warranty was 80% capacity after 10 years Now, my experience with batteries in general is that once they start to go, they deteriorate pretty rapidly; so 80% after 10 years to me basically account 10 years as the lifetime of the battery. £12k for 10 years is £1.2k per year, or £100 per month: that is, the battery would have to allow me to save £100/month in electricity just to break even -- and that's before factoring in the cost of capital (i.e., if I take that £12k and invested it somewhere else, I'd have a lot more than £12k after 10 years). Even if the batteries managed to eke out a reasonable capacity for 20 years -- which seems pretty unlikely to me -- I'd still have to somehow save £50/month to break even. All in all the battery just didn't make financial sense for me as an individual. One expects that the companies doing this on an industrial scale have done the math and managed to find some economies of scale that make it profitable; but it's not out of the realm of possibility that due to a combination of optimism, overselling on the part of battery companies, and FOMO, that they've drastically overestimated the performance of their batteries, and are going to find 15 years down the road that they're beginning to fail without having paid back the capital investment used to buy them.

ChatGTP 3y ago

Anyone else starting to get the feeling that the idea of "base load" power was a scam ? By "base load" I mean the insurmountable blocker for renewable adoption. The storage industry has already proven it can basically double national installed capacity from one year to the next: It did so in 2023 and 2022, and in 2021 it more than tripled the previous year’s tally. The continuation of this trend just gets more impressive with time: A few years ago, doubling storage capacity only meant building 1 gigawatt. Now, the industry is looking at adding 14 gigawatts in a year, requiring an unprecedented amount of work at project sites around the country. It's hard to believe how quickly the renewable revolution is happening. The rise of AI? What about the rise of renewables, holy hell. I was browsing panels the other day for my upcoming project to convert our entire house to solar (we only bought last year, it's top priority for me, for my children's future) and I cannot believe that I can buy top of the range 550W panels for about $200USD per panel, like, my electricity bill is about $400 a month. It's totally ridiculous. I cannot believe people more people haven't caught onto this. I'll be able to pay off the whole system, including batteries in about two year's worth of electricity bills, granted I'm mostly installing myself, it's wild.

otherme123 3y ago
I've been in your boots for 15 years, and I barely convinced anyone. Even my thermal panels are viewed with suspiction, and people don't believe me when I told them my hot water come from them with a little help from an electric heater in the winter. They pay themselves once per year, easily. Frustratingly, the more common doubt is "if it's so good, how are there so few people doing it?" At this point I gave up. I enjoy my free electricity, and even earn some money, but quietly. A pending change in households is going 24/48V DC. The inverters are costly, and they feel stupid when you know a lot of appliances have an AC/DC transformer to undo what your $3K inverters are doing 10 meters away, losing maybe 20% in the process.
- ChatGTP 3y ago
  Frustratingly, the more common doubt is "if it's so good, how are there so few people doing it?" Do you think that 15 years back it was prohibitive from a cost perspective now? Was it always this economically viable? I mean ~ $200 a panel, it's a true no brainer, maybe the initial outlay was a little too much for people way back when? On the other hand, I guess with peaking electricity prices in many parts of the world, it would've easily paid itself off by now for most people.

rapsey 3y ago

Are there other players other than Tesla making these?

DoingIsLearning 3y ago
BYD, Hitachi, Siemens (energy).

dappermanneke 3y ago

a doubling of barely anything is still barely anything

Y-bar 3y ago
Let's play chess. If I win, you send me some rice, ok?
- fbdab103 3y ago
  In case anyone is unfamiliar: https://www.dr-mikes-math-games-for-kids.com/rice-and-chessboard.html https://www.dr-mikes-math-games-for-kids.com/rice-and-chessb... "Oh emperor, my wishes are simple. I only wish for this. Give me one grain of rice for the first square of the chessboard, two grains for the next square, four for the next, eight for the next and so on for all 64 squares, with each square having double the number of grains as the square before." The emperor agreed, amazed that the man had asked for such a small reward - or so he thought. After a week, his treasurer came back and informed him that the reward would add up to an astronomical sum, far greater than all the rice that could conceivably be produced in many many centuries!
- dappermanneke 3y ago
  against what timeframe are you betting a load of money on batteries displacing all fossil fuels
- kgabis 3y ago
  Can the number of grains follow an S-curve?
  - Y-bar 3y ago
    A number of grains can apparently follow many different curves: http://foodfont.com/rice/ http://foodfont.com/rice/

modeless 3y ago

Doubling in 2024 is great but the estimate for 2025 is nowhere near doubling again. How many doublings will we need to store enough energy that solar can replace all non-renewables? I imagine it's still a lot. Edit: this page claims we need 84 times what we had in 2022, the estimate for 2024 is ~3x higher, so call it ~5 more doublings after this year. https://www.alsym.com/blog/how-much-energy-storage-do-we-need-for-a-completely-clean-u-s-electric-grid/ https://www.alsym.com/blog/how-much-energy-storage-do-we-nee...

colechristensen 3y ago
The opposite needs to happen, industry needs to adjust to taking advantage of regular daily energy price swings. Plenty of industries can. Instantaneous pricing for electricity motivates people and industry to make better choices. Very cheap energy will enable interesting things too.
- adrianN 3y ago
  Realistically both things will need to happen. There is a lot of demand that can’t be time shifted by more than a few hours. We need storage for a few weeks of consumption eventually.
- ssl-3 3y ago
  Indeed. As a consumer in Ohio, variable-rate pricing kind of scares me: It's nice to be able to run the clothes dryer without any concern over what time of day it is. We don't do variable-rate pricing here (at least for residential users). But I'd manage to sort it out in pretty short order, I think: It usually isn't very important to me what time of day the clothes get dried (as long as they don't sit long enough to get stinky), so I would indeed be motivated to pay attention to that. I, myself, would even become motivated to automate it so that the clothes begin drying automatically when energy is [relatively] cheap. I can also imagine things like automating water heating: Burn Joules when it is cheap to do so, and store [most of] them for later use at a time that may be more convenient to me. (The math gets interesting on this one.) Having very cheap energy be available occasionally would also be neat: I've got computationally-intensive tasks that need to get done some day. These cost real money to run on the hardware that I have. It sure would be nice if I could save some money by only doing these tasks when power is cheaper. (Right now, I do try to optimize timing them for energy efficiency. For instance, in the summer it is cheaper to run them on cool nights when the windows might be open than during a hot, sunny day when the aircon might barely be keeping up.)

deleted 3y ago

[deleted]