Comment by OliverJones | Hacker News Reader

Comment by OliverJones | Hacker News Reader

Once smart-grid tech starts to emerge, many possibilities to muffle the quacking of the duck curve present themselves.

The most obvious, and applicable in any climate and weather, is domestic hot water heating. Temporarily suspending power to electric hot water heaters at times of high demand can save tons of short-term load. And, it's potentially responsive enough to support frequency control ancillary services (the very expensive task of keeping the power grid running at exactly 60Hz or 50Hz when power demand is changing fast).

Another is electric vehicle charging time-shifting, either mandatory or voluntary.

A third, more complex, opportunity is HVAC. If heating / airconditioning systems can get ahead of their needs during late afternoons, then temporary power suspension in early evenings is feasible. This kind of application may be easiest to deploy in commercial locations like big-box stores, office buildings, and data centers.

A mindset change required is this: demand time-shifting IS energy storage.

A bigger mindset change: grid operators are in the information business, whether they know it or not. All this proposed timeshifting is based on information.

The saying that's now prevalent at utility conferences is, "In the past, we'd forecast load and deploy generation. In the future, we'll forecast generation and deploy load."

This.

Fuel-driven systems offer dispatchable power.

Resource-driven systems offer dispatchable load.

We're used to thinking of idled loads (factories, etc.) as wasted capital, but idled dispatchable power (peaking plant) is the same thing.

The old approach to this is described by the maxim "make hay while the sun shines". Find a task suitable to your current situation, stockpile for downtime.

(The fact that our present fuels are stockpiles of a previous era, that we're burning through at rates of 5 million times that which they accumulated, also bears heeding.)

IIRC, my Dell laptop has a BIOS option to automatically stop charging at certain times of the day, even if it's plugged into the charger. So that's another opportunity: many people seem to use their laptop plugged into the AC most of the time (and into an extra monitor, and into an external keyboard/mouse, etc). With current laptops lasting several hours while unplugged, running them from the internal battery for an hour in times of high demand is viable.

Let's take optimistic assumptions: 50 watts used by a laptop, ~4 hours a day, plugged in and used every day of the year, one laptop per an American, 300M people. All of that multiplies up to 4 * 365 * 50 * 3e+8 = 2.19e+13 watt hours = 2.19e+10 kilowatt hours affected per year. United States uses about 4.1e+12 kilowatt hours per year, that would have an impact of ~1%. Realistically it would probably be 10-100x less.

Although it does seem easy to deploy at scale, at least in the future models.

There is a tradeoff here since involving the battery will increase the overall power consumption. Cycling the battery also shortens its lifespan, and obtaining a replacement costs more energy. I think some degree of centralized control may be needed for this to pay off. That being said, i wonder if there are any existing programs that look at local electricity demand and adjust things accordingly.

then again you could use solar collectors for hot water and heating, eliminating the need for boiling with electric energy

Each of those has major problems.

Water heating is usually natural gas.

Electric vehicle charging during the day prevents charging at home. So employers would need to come on board paying for charging stations with employee parking. And shopping malls, schools, etc.

Heating is also usually natural gas, and while cooling is almost universally electric, it doesn't take very long minutes to a very few hours) in hot weather to consume any reasonable pre-cooling.

Elimination of natural gas water heaters is necessary.

Workplace charging stations isn't so much an employer thing, as a commercial real estate thing. So it's not so much an inconvenience since borrowing money to pay for upgrades of real estate is what those guys are about.

And of course natural gas heating needs to die as well.

I imagine the electric vehicle charging could be time-shifted to overnight. Between 10pm and 6am

Also, energy for water heaters and home heating vary a bit across the country. Electricity is more common in some parts than in others. Even in places that are overwhelmingly gas or propane fueled, the 10% of systems that are electrically powered represent a small but significant opportunity to time-shift demand.

A/C is definitely the largest culprit here, though. And precooling does work if you lower the temperature of the interior thermal mass of the house.

I used to do it when I was subject to random 4-hour A/C shutoffs as part of my discount plan. If I got the house down to 66˚F before the shutoff occurred, the house would remain comfortable for a couple hours. I may have used an overall larger amount of power to do this, but it was the "right" power: drawn from neighbors' solar rather than generating plants.

You could create a heatsink by freezing a mass of water then thawing it. The problem is space for large amounts of water and the high efficiency cooling and distribution system needed.

I can see where you are coming from, but you are likely not aware that a lot of this is already happening. Even my small coop gives out a few hundred dollars in rebates for electric water heaters with remote control. They use this for demand control now.

They also offer cheap ecobee thermostats, with an agreement that they can use them for load leveling. Again, rebates make it practical.

I haven't seen anyone do this with electric cars yet, but its a pretty small leap to imagine utilities offering rebates to businesses for the install, if the result is to shift demand in ways that are useful for the utility. Right now that isn't really necessary here, as the currently small demand for EV charging is mostly at night, and that is already off-peak for our utility.

The replies miss the point:

Shifting from natural gas heating and water heating cannot help flatten the duck curve, except by overall raising the demand for electricity.

Most car charging is currently overnight, which doesn't match use of solar (the low part of the duck curve). To flatten the duck curve, we need to raise that low part and lower the later part.

And if you drop the temperature of the house way low in advance, yes, you use much more power, you reduce the comfort (at least of some people!) And you still only push your peak demand out a little bit. Again, "use more power" isn't a good option to flatten the curve.

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