4 ms·

Sounds like yet another argument for investing in that energy storage low-hanging fruit of thermal reservoirs. Datacenter cooling does not need a huge delta fro

by usrusr 4y ago

Sounds like yet another argument for investing in that energy storage low-hanging fruit of thermal reservoirs. Datacenter cooling does not need a huge delta from ambient, the advantage of pumping against nighttime ambient over pumping against daytime ambient would be huge. Datacenter cooling should be dispatchable demand.

baxtr 4y ago
What does that mean? Could you expand on that?
- corint 4y ago
  At a guess, it'd mean building large slabs of concrete, or tanks of water, or other cheap item with large thermal inertia. Ideally you'd cool these down overnight, or at a period with cheap power, then under regular external temperatures you'd use these to reduce the need for cooling at periods of high power cost. Or, when it's very warm outside, these would work in tandem with the cooling systems to cope with a hot day, with the hope being that overnight you'd catch up, without needing to interrupt workloads.
bob1029 4y ago
I feel like we could do this for homes & businesses too... How big of a thermal battery (assume we are freezing water) would you need to store the cooling capacity of a 5 ton HVAC system running for 1 summer day? Perhaps we could design a new generation of heat pumps with this approach in mind.
- usrusr 4y ago
  Key difference: homes and small businesses buy electricity at a fixed rate, large datacenters are big enough for dynamic prices. In a market that doesn't completely abandon fixed rate prices this isn't really possible for smaller customers, because offering dynamic rates requires some trust that the consumer doesn't abuse the fixed rate by dynamically selecting whatever is cheaper at the time. This trust can only be established for consumers large enough for people checking the numbers and perhaps even the occasional audit.
  - bob1029 4y ago
    This is the case now, but it wasn't always. In Texas, we used to have residential plans where you payed wholesale rates for electricity (e.g. Griddy). I used to be on one of these plans and would constantly fantasize about being able to accumulate HVAC capacity at night when you would sometimes be paid to consume electricity.
    - usrusr 4y ago
      Did the "least cost router" scenario ever come up? I'd imagine that a certain kind of people would feel very much entitled to e.g. share consumption with a neighbor, switching both houses to a shared meter on either variable or fixed rate based on time of day, and power retailers frantically balancing between chasing them looking for suspicious patterns and pretending that it never happened to avoid inspiring others. (I do believe that switching to variable rates would be a good idea, that in even the poorest of the poor would the grand scheme of things be better off if they had to occasionally disconnect, less bad than if the alternative was the entire grid occasionally browning out, including services that might be more important to them than their home consumption. And peak prices would even be as high as they are now, if they weren't propped up by an army of fixed rate consumers who don't show any have of demand flexibility almost be definition)
      - bob1029 4y ago
        > I do believe that switching to variable rates would be a good idea Completely agree. Any time we try to control/subsidize costs we introduce instabilities and bad incentives into the marketplace. Texas grid was about as close as you could get to reality for a while. I would much prefer a situation where everyone is impacted by the cost in the same way. At grid scale, nothing can be stored, so financial arbitrage is effectively a scam.
- nucleardog 4y ago
  If you (as a person) can tolerate cooler temperatures well, you can already do this to some extent using the house itself as a thermal battery. Run your A/C overnight when power is cheaper and the air conditioner is more efficient (and rolling blackouts are less likely...). Cool your house to say 4-8F cooler than you'd normally keep it (close off some vents in your bedroom if you need to, though personally I prefer sleeping in the cold). If your house is well insulated you may be able to make it through a significant portion of the next day without the air conditioner needing to cut in again. In the grand scheme of things wood doesn't have a lot of thermal mass, but if there's a lot of it it still adds up. Even as the air begins to warm, the floor and walls still feel noticeably cooler.

by usrusr 4y ago

baxtr 4y ago

What does that mean? Could you expand on that?

corint 4y ago
At a guess, it'd mean building large slabs of concrete, or tanks of water, or other cheap item with large thermal inertia. Ideally you'd cool these down overnight, or at a period with cheap power, then under regular external temperatures you'd use these to reduce the need for cooling at periods of high power cost. Or, when it's very warm outside, these would work in tandem with the cooling systems to cope with a hot day, with the hope being that overnight you'd catch up, without needing to interrupt workloads.

bob1029 4y ago

I feel like we could do this for homes & businesses too... How big of a thermal battery (assume we are freezing water) would you need to store the cooling capacity of a 5 ton HVAC system running for 1 summer day? Perhaps we could design a new generation of heat pumps with this approach in mind.

usrusr 4y ago
Key difference: homes and small businesses buy electricity at a fixed rate, large datacenters are big enough for dynamic prices. In a market that doesn't completely abandon fixed rate prices this isn't really possible for smaller customers, because offering dynamic rates requires some trust that the consumer doesn't abuse the fixed rate by dynamically selecting whatever is cheaper at the time. This trust can only be established for consumers large enough for people checking the numbers and perhaps even the occasional audit.
- bob1029 4y ago
  This is the case now, but it wasn't always. In Texas, we used to have residential plans where you payed wholesale rates for electricity (e.g. Griddy). I used to be on one of these plans and would constantly fantasize about being able to accumulate HVAC capacity at night when you would sometimes be paid to consume electricity.
  - usrusr 4y ago
    Did the "least cost router" scenario ever come up? I'd imagine that a certain kind of people would feel very much entitled to e.g. share consumption with a neighbor, switching both houses to a shared meter on either variable or fixed rate based on time of day, and power retailers frantically balancing between chasing them looking for suspicious patterns and pretending that it never happened to avoid inspiring others. (I do believe that switching to variable rates would be a good idea, that in even the poorest of the poor would the grand scheme of things be better off if they had to occasionally disconnect, less bad than if the alternative was the entire grid occasionally browning out, including services that might be more important to them than their home consumption. And peak prices would even be as high as they are now, if they weren't propped up by an army of fixed rate consumers who don't show any have of demand flexibility almost be definition)
    - bob1029 4y ago
      > I do believe that switching to variable rates would be a good idea Completely agree. Any time we try to control/subsidize costs we introduce instabilities and bad incentives into the marketplace. Texas grid was about as close as you could get to reality for a while. I would much prefer a situation where everyone is impacted by the cost in the same way. At grid scale, nothing can be stored, so financial arbitrage is effectively a scam.
nucleardog 4y ago
If you (as a person) can tolerate cooler temperatures well, you can already do this to some extent using the house itself as a thermal battery. Run your A/C overnight when power is cheaper and the air conditioner is more efficient (and rolling blackouts are less likely...). Cool your house to say 4-8F cooler than you'd normally keep it (close off some vents in your bedroom if you need to, though personally I prefer sleeping in the cold). If your house is well insulated you may be able to make it through a significant portion of the next day without the air conditioner needing to cut in again. In the grand scheme of things wood doesn't have a lot of thermal mass, but if there's a lot of it it still adds up. Even as the air begins to warm, the floor and walls still feel noticeably cooler.