[leetrout]

Never heard of a "virtual power plant". So they are aggregate power generation instead of a fixed plant... interesting naming choice.

> Virtual power plants, generally considered a connected aggregation of distributed energy resource (DER) technologies, offer deeper integration of renewables and demand flexibility, which in turn offers more Americans cleaner and more affordable power.

https://www.energy.gov/lpo/virtual-power-plants

[gwbas1c]

One example is coordinating Tesla Powerwalls (home battery backup): https://www.tesla.com/support/energy/virtual-power-plant/pge

> By becoming a part of the Tesla Virtual Power Plant (VPP) with PG&E, your Powerwall will be dispatched when the grid needs emergency support. Through the Emergency Load Reduction Program (ELRP), you will receive $2.00 for every additional kWh your Powerwall delivers during an event.

I should point out that I have a Powerwall, and I have no incentive from my electric utility to use it in any way. Overall, with rebates, it cost slightly more than a standby generator, and but it requires no maintenance, so it's "worth it" for me.

But, $2.00 back on a kwh is pretty nice, IMO.

[noveltyaccount]

Wow - $2.00 is crazy. I pay $0.15 per kWh (pacific northwest, inexpensive hydroelectric power). 13X, quite an incentive, even if rare.

[zbrozek]

California's PG&E is the biggest utility in the US. In their territory electricity on the default residential plan ranges from $0.41 to $0.54 per KWh.

[gwbas1c]

Still, that's 4x back. It really helps incentivize buying a larger powerwall, and disincentivizes the power company from sapping the battery dry right before you need it.

[zbrozek]

Yeah, I'm not saying it's a bad deal for the battery owner, but rather that it isn't the huge spread that you had assumed based on a reasonable electricity price. :shrug:

[Scoundreller]

How many hours a year would one expect to get this?

[callalex]

And they’re raising prices again next year.

[toomuchtodo]

You're paying retail rate. The utility pays spot prices and attempts to manage the spot price vs retail rate spread over a window of time.

[Scoundreller]

Why $2 though? When prices hit $1.50, they’ll just hit up their physical generators instead of your battery?

[SamBam]

To be clear, I think it's as much about the aggregation of "Distributed Energy Resources," DERs, as about the aggregation of generation.

From my understanding, a DER can be as simple as a smart thermostat that can receive a signal from the utility company to set the AC up a couple of degrees during a period of high electricity demand.

As energy is fungible, saving 1kW by turning off 1kW of less-necessary usage is exactly the same as generating an additional 1kW to cope with demand.

[magicalhippo]

> exactly the same

Of course except it's only the same if they're closely connected.

Here in Norway, while energy regions are connected throughout the country, the cables are quite limited between certain areas. So generation here might not help for usage there.

So being able to control usage, or having extra batteries connected near the loads, can be even more useful than extra generator capacity far away.

[jakewins]

Aye but y'all are way ahead! I get to hack on software that bids into DSO-level circuits for NODES up in Norway.

I imagine Norway is seeing a lot of the issues - and opportunities - that having high EV penetration brings, so a good place to watch for what works and what doesn't.

[soulofmischief]

Exactly the same, except during the hottest and coldest parts of the year, I pay an electric bill and still feel miserable.

[ZeroGravitas]

The point of these schemes is to provide you with energy at precisely those hottest/coldest parts of the year. If you want to pay more for potentially redundant backup and/or take the risk of the whole system going down, then you're only going to be more miserable.

[soulofmischief]

Yes, I am aware of how these schemes are marketed. I have lived in homes that use these schemes and it's not worth it.

Maybe you live in a better climate, but not getting adequate heating or cooling when I need it most negates the entire purpose of having heating and cooling.

[ghouse]

It's a horrible naming choice and it shows the industry preconception that a power plant is a large, transmission-interconnected facility.

It also, IMHO holds on to an outdated concept that all generation must be centrally dispatched. There are plenty of concepts that allow distributed dispatch including voltage (which in turn can be controlled based on local conditions).

Finally (and perhaps most importantly), it implies that only devices that export generation are part of the solution. The supply and demand must be balanced in real-time. And the demand side of the equation is often much less expensive than the supply side.

[idiotsecant]

What? It's the opposite of literally all these things.

[sunk1st]

Yeah I think that’s why GP is saying it’s a poor choice of name.

[SamBam]

But if the industry is the one naming it, why are they going against their own "preconceptions?"

I feel like GGP is the one with the preconception about the name "power plant," while the industry (as shown here) is starting to use it to be this broader term encompassing distributed generation and price-influenced demand, etc etc.

[ghouse]

As an industry, the term "power plant" is something that generates power (electric energy). However, much of the DER opportunity is not generation, but load. Which is why the term "Virtual Power Plant" is a misnomer and predisposes people to only be thinking about the generation side of the supply/demand equation.

[SamBam]

Right, but it's precisely that shift that the term is supposed to induce. From a fungible energy perspective, there really isn't that much difference between increasing the supply by an additional MW and decreasing the demand by an additional MW. Moreover, that additional MW that's now in the grid is the greenest possible energy, provided without producing a single atom of CO2.

When people thinking about generation they think about something different than reducing demand, but it's critical to start seeing that those can be the same thing, in certain circumstances.

[ZeroGravitas]

Virtual Power Plants, both in general (see first sentence on wikipedia: https://en.wikipedia.org/wiki/Virtual_power_plant), and specifically in the definition given in the comment you replied to, include "demand flexibility" so your comment is confusing.

[garba_dlm]

it's an attempt to bridge the language

because you're right, the people that own this stuff (and work on these companies) are used to thinking in terms of large transmission-interconnected facilities.

so my take this move has most to do with how to bill people, and how to collect payments and pay taxes on said payments and so on. I expect that the actual electrical engineering is treated as an implementation detail

[7thaccount]

Yes. VPPs was the more common academic term used for many years. Recently, FERC came out with Order 2222 that essentially paved the way for Distributed Energy Resources (DERs) to participate in the wholesale electricity markets (think organizations like CAISO that determine the optimal schedules for thousands of power plants on an hourly and 5-minute basis via a market) via a DER Aggregator.

So if you take all these infinitesimally small sources and add them up, a single entity can be a market player for them as a kind of tiny virtual power plant. Naturally, this is extremely complicated and took years to get through the legal processes and for the various grid operators to get it figured out. It's still a work in progress.

[hosh]

I heard of the concept for some time but I guess someone is coining it as a term to make it an easier sell.

[Animats]

Right, this is new hype for an old concept. It's mostly load management, with some batteries.

Calling this "virtual power plants" is deceptive. It doesn't generate power. It just moves the load around in time a bit. There are limits to how much benefit that can yield. At some point, customers will want to heat their water or charge their car.

Much of this is a attempt to deal with the problem of intermittent wind power. Wind power varies about 4:1 over the course of a day. Here's today's graph for CAISO, for the West Coast.[1] And for PJM, for the East Coast[2]. Both had about a 4:1 range today, and for both, it bottomed out about now, in late morning. A huge tie line from California to Pennsylvania would not have helped. Peak wind output today was before dawn, which is the lowest period for load.

At least with solar you know when there's going to be output. But even that can vary about 2:1 from day to day in PJM's area.[3]

The important question to ask is, if the grid has N hours of storage, how often is there a power shortage? What should N be? A few hours? A few days?

[1] https://www.caiso.com/TodaysOutlook/Pages/supply.html

[2] https://dataviewer.pjm.com/dataviewer/pages/public/wind.jsf

[3] https://dataviewer.pjm.com/dataviewer/pages/public/solar.jsf

[sanderjd]

> It's mostly load management, with some batteries.

There is some amount of distributed generation out there as well, in the form of either oil or natural gas backup generators, which can be used similarly as batteries.

Edit to add: This wasn't meant as a disagreement with your point. I don't think the existence of a small amount of generation changes the fundamental equation you pointed out on this.