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An increasingly-viable alternative to global transmission interconnectivity is distributed energy resources (behind the meter, on utility-customer sites). The

An increasingly-viable alternative to global transmission interconnectivity is distributed energy resources (behind the meter, on utility-customer sites). The latter offers better resiliency and lower transmission / distribution losses. A well-insulated building and its hot-water tank are both (thermal) energy storage systems, that are more durable (and more affordable) than electrochemical batteries. A building can be pre-cooled or pre-heated when on-site solar is plentiful, to the end of the occupant's comfort range. This means a smaller on-site battery bank is needed to achieve year-around grid independence (for a conditioned / comfortable building). It seems that we're just getting started with on-site flexible-load control, and building energy automation generally. The higher electric rates in some markets make it financially viable for end users today.

lrobinovitch 5y ago
I work in the field of distributed energy resources and it’s incredibly cool. We’re remote first and hiring. https://www.voltus.co https://www.voltus.co
- caminante 5y ago
  It'd be interesting if you can scale and reach profitability. It seems like a reboot of EnerNoc and has much of the same team. EnerNoc was burning ~50 million/y on 400 million revenues before it was purchased at a discount by Enel. [0] [0]https://www.greentechmedia.com/articles/read/enel-to-buy-enernoc-for-250-million https://www.greentechmedia.com/articles/read/enel-to-buy-ene...
  - lrobinovitch 5y ago
    Yep, much of the same team, with a different strategy (more tech-focused and participation in more energy market programs). Regulation of DERs largely killed EnerNoc, now Enel X, and the like. Voltus' CEO helped repeal the order[1], ensuring DERs make parity with conventional generators. > if you can scale and reach profitability I don't know what I can actually reveal, but scaling is our focus right now. [1] https://www.ferc.gov/sites/default/files/2020-06/Order-745.pdf https://www.ferc.gov/sites/default/files/2020-06/Order-745.p...
    - caminante 5y ago
      That was a win! In power markets, it's really hard scaling around each market/state's idiosyncracies almost like it's not a technology problem and more regulatory/financing. Hope you guys figure it out.
      - lrobinovitch 5y ago
        100%, well put. Our energy markets team is larger than our engineering team :). But it's also certainly a technology problem in that meeting each market's idiosyncratic requirements requires technology.
- cudgy 5y ago
  Hope you don’t get gobbled up by the energy behemoths that love the centralized grid model.
- newyankee 5y ago
  Do you hire data analysts/ scientists ?
  - lrobinovitch 5y ago
    Yep, contact me at leo@voltus.co
eru 5y ago
Technology Connections has an interesting video about pre-cooling: https://www.youtube.com/watch?v=0f9GpMWdvWI https://www.youtube.com/watch?v=0f9GpMWdvWI The author also made a good point that despite wind and solar being intermittent, they are actually fairly predictable a or less day in advance (thanks to weather forecasts).
- pfdietz 5y ago
  You can see this play out in Texas, at the ERCOT dashboard. https://mis.ercot.com/public/dashboards https://mis.ercot.com/public/dashboards Interestingly, you can see that wind and solar are anticorrelated there: wind tends to die down during the day, and spring back up at night.
- mcbishop 5y ago
  The video is super articulate. I like what he did at 6:49: > So that I can take advantage of these low rates at night, I use a roughly 16kWh battery that I just happen to have lying around. I charge it up over night starting at 10pm on the dot, and it's done charging usually by 3 or 4 in the morning. I keep it topped off until around 7, and then I start using it during the day. And it doesn't need to be charged again until the evening. Now the reason I just happen to have that battery lying around, is because that battery... is my house.
cinquemb 5y ago
> … (thermal) energy storage systems, that are more durable (and more affordable) than electrochemical batteries… Agree, I think for so long the whole renewable build out has ignored storage costs which will really come to bite electrochemical battery dependent systems in the ass (because banks like UBS have long projected that costs will be harder and harder to bring down and ACS has long talked about the difficult to deal with chemistries with all the different batteries out there [and with the inherit degradation of the system over time]). I think in the long run (well, unless our political challenges with nuclear get solved), on the utility level (potentially even behind the meter for specific high energy applications that have space to construct/"mine" their own solar field), molten salt storage will take the lead (esp as salt mixtures/chemistries get cheaper, have higher thermal operating ranges, storage and transportation gets better).
- pfdietz 5y ago
  Thermal storage in hot sand seems superior. Sand is cheaper, capable of operating at high temperature, and allowing heat exchange to the working gas by direct contact in a fluidized bed heat exchanger. https://arpa-e.energy.gov/sites/default/files/2021-03/07%20Day1-Zhiwen%20Ma_NREL.pdf https://arpa-e.energy.gov/sites/default/files/2021-03/07%20D...
  - cinquemb 5y ago
    I deff would like to see a 100MW sand system built out. I think the sand direction is deff an improvement over the 300 delta_C systems now with (NaNO3, KNO3, NaNO2) at the 900 delta_C in used in the pdf, but idk if it will win out in the long run with the need for direct contact vs some kind of sCO2 system with higher delta_C mixtures (for example a theoretical mixture CaCl2 + MgCl2 with 1500 delta_C, or even engineered metamaterials[0, i've only seen some specific examples of electromagnetic metameterials when i was in school about a decade ago, this post was about a year after i left] in a mixture to have even higher delta_c). There's only so much one can do when one limits the materials used for heat capacity to naturally occurring ones (i imagine that compounds in the future could be engineered to be at least a order of magnatude higher in delta_c from natural mixtures). [0] https://news.brown.edu/articles/2012/10/quantum https://news.brown.edu/articles/2012/10/quantum
dn3500 5y ago
I live in a 200 year old house in Mexico. The walls are half a meter thick. At night we open the windows, which are oriented toward the prevailing winds, and the house cools down. Mid-morning we close it all up and it stays cool all day. Meanwhile people with modern houses have to run their air conditioning to keep cool.
- grecy 5y ago
  I saw exactly this in 2000 year old homes in Morocco where the temps are regularly 120F+ in the summer and below freezing at night in the winter. Without need of electricity there absolutely zero issues with heat or cold.
  - madengr 5y ago
    Lack of humidity helps.
- sildur 5y ago
  I have had arguments with Americans who are absolutely convinced that wasting energy in an AC is good and something to be proud of, while opening windows is primitive, and bad. It was funny.
  - eru 5y ago
    I somewhat suspect that you are being a bit uncharitable towards their position here.
    - sildur 5y ago
      They are adults. Them being wrong is their problem, not mine.
      - eru 5y ago
        I am saying that they probably didn't say what you said they did. Doesn't matter. I don't know these people.
OneTimePetes 5y ago
One another option is gravity storage- with (exotic idea alarm) a ice piston in isolation material. Basically create a artificial vertical glacier and transport the heat from the cooling into a separate storage "hot well". Then use and abuse accordingly. https://www.youtube.com/watch?v=ObvQFX6noDw https://www.youtube.com/watch?v=ObvQFX6noDw
- mcbishop 5y ago
  That's really cool (dad pun intended). I don't understand the ice component though... is the heat capture an ancillary benefit? One web-search result uses a rock mass: https://heindl-energy.com/ https://heindl-energy.com/.

lrobinovitch 5y ago

I work in the field of distributed energy resources and it’s incredibly cool. We’re remote first and hiring. https://www.voltus.co https://www.voltus.co

caminante 5y ago
It'd be interesting if you can scale and reach profitability. It seems like a reboot of EnerNoc and has much of the same team. EnerNoc was burning ~50 million/y on 400 million revenues before it was purchased at a discount by Enel. [0] [0]https://www.greentechmedia.com/articles/read/enel-to-buy-enernoc-for-250-million https://www.greentechmedia.com/articles/read/enel-to-buy-ene...
- lrobinovitch 5y ago
  Yep, much of the same team, with a different strategy (more tech-focused and participation in more energy market programs). Regulation of DERs largely killed EnerNoc, now Enel X, and the like. Voltus' CEO helped repeal the order[1], ensuring DERs make parity with conventional generators. > if you can scale and reach profitability I don't know what I can actually reveal, but scaling is our focus right now. [1] https://www.ferc.gov/sites/default/files/2020-06/Order-745.pdf https://www.ferc.gov/sites/default/files/2020-06/Order-745.p...
  - caminante 5y ago
    That was a win! In power markets, it's really hard scaling around each market/state's idiosyncracies almost like it's not a technology problem and more regulatory/financing. Hope you guys figure it out.
    - lrobinovitch 5y ago
      100%, well put. Our energy markets team is larger than our engineering team :). But it's also certainly a technology problem in that meeting each market's idiosyncratic requirements requires technology.
cudgy 5y ago
Hope you don’t get gobbled up by the energy behemoths that love the centralized grid model.
newyankee 5y ago
Do you hire data analysts/ scientists ?
- lrobinovitch 5y ago
  Yep, contact me at leo@voltus.co

eru 5y ago

Technology Connections has an interesting video about pre-cooling: https://www.youtube.com/watch?v=0f9GpMWdvWI https://www.youtube.com/watch?v=0f9GpMWdvWI The author also made a good point that despite wind and solar being intermittent, they are actually fairly predictable a or less day in advance (thanks to weather forecasts).

pfdietz 5y ago
You can see this play out in Texas, at the ERCOT dashboard. https://mis.ercot.com/public/dashboards https://mis.ercot.com/public/dashboards Interestingly, you can see that wind and solar are anticorrelated there: wind tends to die down during the day, and spring back up at night.
mcbishop 5y ago
The video is super articulate. I like what he did at 6:49: > So that I can take advantage of these low rates at night, I use a roughly 16kWh battery that I just happen to have lying around. I charge it up over night starting at 10pm on the dot, and it's done charging usually by 3 or 4 in the morning. I keep it topped off until around 7, and then I start using it during the day. And it doesn't need to be charged again until the evening. Now the reason I just happen to have that battery lying around, is because that battery... is my house.

cinquemb 5y ago

> … (thermal) energy storage systems, that are more durable (and more affordable) than electrochemical batteries… Agree, I think for so long the whole renewable build out has ignored storage costs which will really come to bite electrochemical battery dependent systems in the ass (because banks like UBS have long projected that costs will be harder and harder to bring down and ACS has long talked about the difficult to deal with chemistries with all the different batteries out there [and with the inherit degradation of the system over time]). I think in the long run (well, unless our political challenges with nuclear get solved), on the utility level (potentially even behind the meter for specific high energy applications that have space to construct/"mine" their own solar field), molten salt storage will take the lead (esp as salt mixtures/chemistries get cheaper, have higher thermal operating ranges, storage and transportation gets better).

pfdietz 5y ago
Thermal storage in hot sand seems superior. Sand is cheaper, capable of operating at high temperature, and allowing heat exchange to the working gas by direct contact in a fluidized bed heat exchanger. https://arpa-e.energy.gov/sites/default/files/2021-03/07%20Day1-Zhiwen%20Ma_NREL.pdf https://arpa-e.energy.gov/sites/default/files/2021-03/07%20D...
- cinquemb 5y ago
  I deff would like to see a 100MW sand system built out. I think the sand direction is deff an improvement over the 300 delta_C systems now with (NaNO3, KNO3, NaNO2) at the 900 delta_C in used in the pdf, but idk if it will win out in the long run with the need for direct contact vs some kind of sCO2 system with higher delta_C mixtures (for example a theoretical mixture CaCl2 + MgCl2 with 1500 delta_C, or even engineered metamaterials[0, i've only seen some specific examples of electromagnetic metameterials when i was in school about a decade ago, this post was about a year after i left] in a mixture to have even higher delta_c). There's only so much one can do when one limits the materials used for heat capacity to naturally occurring ones (i imagine that compounds in the future could be engineered to be at least a order of magnatude higher in delta_c from natural mixtures). [0] https://news.brown.edu/articles/2012/10/quantum https://news.brown.edu/articles/2012/10/quantum

dn3500 5y ago

I live in a 200 year old house in Mexico. The walls are half a meter thick. At night we open the windows, which are oriented toward the prevailing winds, and the house cools down. Mid-morning we close it all up and it stays cool all day. Meanwhile people with modern houses have to run their air conditioning to keep cool.

grecy 5y ago
I saw exactly this in 2000 year old homes in Morocco where the temps are regularly 120F+ in the summer and below freezing at night in the winter. Without need of electricity there absolutely zero issues with heat or cold.
- madengr 5y ago
  Lack of humidity helps.
sildur 5y ago
I have had arguments with Americans who are absolutely convinced that wasting energy in an AC is good and something to be proud of, while opening windows is primitive, and bad. It was funny.
- eru 5y ago
  I somewhat suspect that you are being a bit uncharitable towards their position here.
  - sildur 5y ago
    They are adults. Them being wrong is their problem, not mine.
    - eru 5y ago
      I am saying that they probably didn't say what you said they did. Doesn't matter. I don't know these people.

OneTimePetes 5y ago

One another option is gravity storage- with (exotic idea alarm) a ice piston in isolation material. Basically create a artificial vertical glacier and transport the heat from the cooling into a separate storage "hot well". Then use and abuse accordingly. https://www.youtube.com/watch?v=ObvQFX6noDw https://www.youtube.com/watch?v=ObvQFX6noDw

mcbishop 5y ago
That's really cool (dad pun intended). I don't understand the ice component though... is the heat capture an ancillary benefit? One web-search result uses a rock mass: https://heindl-energy.com/ https://heindl-energy.com/.