4 ms·

That's an interesting point, in aggregate. As we move towards more intermittent renewables, assuming the market remains intermittent, there's an entire new cla

by ethbro 7y ago

That's an interesting point, in aggregate. As we move towards more intermittent renewables, assuming the market remains intermittent, there's an entire new class of demand that's feasible. Essentially anything that "only needs power sometime in the next week, can soak up a semi-arbitrary amount of power, and can start/stop quickly (ideally grid-controlled)."

Scoundreller 7y ago
I also think we haven't fully exploited interrmittent/responsive demand. I'd have no issues if a household or building's HVAC system, hot water system, electric car chargers ebbed and flowed their demand in response to supply. E.g. when I turn on my dishwasher, I don't care if it holds for 2 hours and then runs because the winds are calm now, but expected to pickup in 2 hours. I don't care if my hot water heater superheats water now because it's especially sunny or windy out. I don't care if my electric car chargers over the course of 8 hours in the evening, instead of charging quickly now. I don't care if my AC system makes the building a couple of degrees cooler now to thermal bank the excess supply before rates increase later.
- ethbro 7y ago
  The issue seems to be that energy markets are a long way from achieving financial market levels of responsiveness. You're essentially increasing the number of market participants a couple orders of magnitude, and the system and existing players semi-understandably balk. On the other hand, without exposure to end users, the utility-driven pace of change is going to be glacial (by which I mean, we won't have glaciers anymore either).
  - Scoundreller 7y ago
    We already have "smart-meters" that enable time-of-day billing. They just need to monitor usage on a per 5-minute basis (and I suspect they do). They don't necessarily need to report it every 5 mins (otherwise how does the current system know how to respond to demand?). I do feel like we should start billing on per-5-minute increments, then the responsiveness will come. I think overnight we'll have a thousand startups selling devices that turn on/off your HVAC or car charger accordingly and save you money overall. Possibly even with a warmer home in winter or cooler home in summer, by being strategic.
    - danans 7y ago
      > They don't necessarily need to report it every 5 mins (otherwise how does the current system know how to respond to demand?). Supply is managed at the ISO level (a grid subsection, like the entire California grid), not the individual consumer level. The ISO monitors the AC frequency of the grid, which varies with the imbalance of supply and demand. The ISO contracts with "spinning reserve" generators who supply power to the grid at low latencies when needed to meet demand, a service known as frequency regulation. There are efforts underway to provide frequency regulation via demand control and battery storage instead of spinning reserves, which are typically Nat gas turbine powered.
      - Scoundreller 7y ago
        Right, but why not let my electric car or water heater take part in that market? Instead of spinning up a natgas turbine, why not let my water heater or car charger take a break as a part of the market? There are some grid level implementations of this (install our thermostat that we can remotely turn off to get a 5% rebate), but these seem to work around the primary problem: we pay an average price for electricity, not the actual price. And if it all works based on grid frequency, the system could even work offline: water heater sees frequency drop and takes a random break between 1 and 60 minutes. Or variable-frequency drive AC drops 10% in intensity, or increases by x% when frequency is getting a little high.
        danans 7y ago
        > Right, but why not let my electric car or water heater take part in that market? Instead of spinning up a natgas turbine, why not let my water heater or car charger take a break as a part of the market? Indeed, that's precisely what I meant by frequency regulation via demand control and batteries.
        ethbro 7y ago
        (I'm not an electrical engineer) The problem I was thinking about was demand harmonics. It's not unreasonable to envision a scenario where a large number of independent devices, acting in their own self interest, end up oscillating between on and off together. E.g. by using the same logic. It seems like you need something approaching a parallelism primative to coordinate behavior. E.g. bid two steps in advance, find out if your bid was accepted one step in advance, then act. Or is bidding in energy markets already complex enough to avoid that outcome?
- archi42 7y ago
  In Austria and recently (since April?) there is a provider called Awattar. They sell energy with a flexible price model that's based on the energy spot market. They claim "you might even get paid to consume power". My car charger can interface with them, and do exactly what you suggest. In theory you "just" need smart controllers for the systems. The idea is similar to 1980s "Storage heaters", which would use cheaper nighttime power; but using fossile electricity this is very inefficient and thus bad for the environment - when exclusively using excess regenerative energy that's different though. Same for AC. The problem is when there is no excess energy for a long time; so I'd personally go with a hybrid system for heating (regenerative energy when available for a heat pump, local solar thermal energy for "base load" heating/warm water - not sure if fossil fuel for winter is necessary with that, but that depends on your climate).
pfdietz 7y ago
One very interesting example of this is high temperature storage of heat for industrial use. http://news.mit.edu/2017/firebricks-low-cost-storage-carbon-free-energy-0906 http://news.mit.edu/2017/firebricks-low-cost-storage-carbon-...

by ethbro 7y ago

Scoundreller 7y ago

I also think we haven't fully exploited interrmittent/responsive demand. I'd have no issues if a household or building's HVAC system, hot water system, electric car chargers ebbed and flowed their demand in response to supply. E.g. when I turn on my dishwasher, I don't care if it holds for 2 hours and then runs because the winds are calm now, but expected to pickup in 2 hours. I don't care if my hot water heater superheats water now because it's especially sunny or windy out. I don't care if my electric car chargers over the course of 8 hours in the evening, instead of charging quickly now. I don't care if my AC system makes the building a couple of degrees cooler now to thermal bank the excess supply before rates increase later.

ethbro 7y ago
The issue seems to be that energy markets are a long way from achieving financial market levels of responsiveness. You're essentially increasing the number of market participants a couple orders of magnitude, and the system and existing players semi-understandably balk. On the other hand, without exposure to end users, the utility-driven pace of change is going to be glacial (by which I mean, we won't have glaciers anymore either).
- Scoundreller 7y ago
  We already have "smart-meters" that enable time-of-day billing. They just need to monitor usage on a per 5-minute basis (and I suspect they do). They don't necessarily need to report it every 5 mins (otherwise how does the current system know how to respond to demand?). I do feel like we should start billing on per-5-minute increments, then the responsiveness will come. I think overnight we'll have a thousand startups selling devices that turn on/off your HVAC or car charger accordingly and save you money overall. Possibly even with a warmer home in winter or cooler home in summer, by being strategic.
  - danans 7y ago
    > They don't necessarily need to report it every 5 mins (otherwise how does the current system know how to respond to demand?). Supply is managed at the ISO level (a grid subsection, like the entire California grid), not the individual consumer level. The ISO monitors the AC frequency of the grid, which varies with the imbalance of supply and demand. The ISO contracts with "spinning reserve" generators who supply power to the grid at low latencies when needed to meet demand, a service known as frequency regulation. There are efforts underway to provide frequency regulation via demand control and battery storage instead of spinning reserves, which are typically Nat gas turbine powered.
    - Scoundreller 7y ago
      Right, but why not let my electric car or water heater take part in that market? Instead of spinning up a natgas turbine, why not let my water heater or car charger take a break as a part of the market? There are some grid level implementations of this (install our thermostat that we can remotely turn off to get a 5% rebate), but these seem to work around the primary problem: we pay an average price for electricity, not the actual price. And if it all works based on grid frequency, the system could even work offline: water heater sees frequency drop and takes a random break between 1 and 60 minutes. Or variable-frequency drive AC drops 10% in intensity, or increases by x% when frequency is getting a little high.
      - danans 7y ago
        > Right, but why not let my electric car or water heater take part in that market? Instead of spinning up a natgas turbine, why not let my water heater or car charger take a break as a part of the market? Indeed, that's precisely what I meant by frequency regulation via demand control and batteries.
        ethbro 7y ago
        (I'm not an electrical engineer) The problem I was thinking about was demand harmonics. It's not unreasonable to envision a scenario where a large number of independent devices, acting in their own self interest, end up oscillating between on and off together. E.g. by using the same logic. It seems like you need something approaching a parallelism primative to coordinate behavior. E.g. bid two steps in advance, find out if your bid was accepted one step in advance, then act. Or is bidding in energy markets already complex enough to avoid that outcome?
archi42 7y ago
In Austria and recently (since April?) there is a provider called Awattar. They sell energy with a flexible price model that's based on the energy spot market. They claim "you might even get paid to consume power". My car charger can interface with them, and do exactly what you suggest. In theory you "just" need smart controllers for the systems. The idea is similar to 1980s "Storage heaters", which would use cheaper nighttime power; but using fossile electricity this is very inefficient and thus bad for the environment - when exclusively using excess regenerative energy that's different though. Same for AC. The problem is when there is no excess energy for a long time; so I'd personally go with a hybrid system for heating (regenerative energy when available for a heat pump, local solar thermal energy for "base load" heating/warm water - not sure if fossil fuel for winter is necessary with that, but that depends on your climate).

pfdietz 7y ago

One very interesting example of this is high temperature storage of heat for industrial use. http://news.mit.edu/2017/firebricks-low-cost-storage-carbon-free-energy-0906 http://news.mit.edu/2017/firebricks-low-cost-storage-carbon-...