virtual power plant, anyone observing

ggelitetrader000 · Jul 30, 2020

Trader200K said:
While the basics of 'community grid/power sharing' seems attractive, there are a ton of practical issues.

Economics is a big one. Large wholesale genco plants efficiently produce cheap power through economies of scale. Distribution companies buy power wholesale and will not want to essentially start paying retail by allowing customers to offset on a direct kWh basis. Granted consumers have zero fuel cost, but also they have a very large investment in panels/etc to amortize. Mass numbers of consumers won't screw with doing it without financial value in return, especially if payback runs 10-15+ years. They will not be happy to see their arrays pumping out max current with some variable rate paid by the distribution company shrunk to zero ... like happened to large wind farms when power companies give preference to their internal generation assets because of their fixed costs. Using customers for occasional peak shaving is no value to the home solar owner. Ongoing time/expense of maintenance of the complex system also falls now to the home owner. Complexity is expensive to repair.

So rates for reverse power purchase will likely have to be at wholesale, making payback iffy for the homeowner. If govt forces the ute to pay more than wholesale without rate increases, grid maintenance is threatened. Like Maduro pricing kWh below cost and subsidizing with oil revenue ... that dried up and took their grid reliability with it.

Let's say you actually get to the place where consumers generate as much power as several old plants that got decommissioned. What if conditions change and large numbers of people, for reason X, decide to pull their plug from the program? Will the govt force them to remain, invest more? Spend time screwing with something they don't want to do? The ute's alternative is to buy expensive grid intertie power to keep the lights on while building new plants. Will spare intertie energy even be available at all?

Then from a technical perspective, the permutations of say 50,000 consumer grade inverters buzzing a bell curve of currents/frequencies into distribution feeders will make the operation of power dispatch and troubleshooting for boots on the ground linemen an absolute nightmare trying to maintain voltage/power factor/etc standards within required tolerance. All the engineering assumptions of the original grid design are out the window.

A tree breaks a line, one or more consumer's inverter fail's to clear and it continues to push 220 back into the local transformer, making 7200v+ on the primary side where the lineman is getting ready for his broken strand repair. Would you want that job?

Or imagine the sun pops out, everybody is up, large reverse currents hits a substation and the bulk grid behind it has no place to send the current. If dispatch can't shut all/enough of the back feeders off, voltage spikes and breakers open and a bunch of grandmas' oxygen concentrators, water pumps and sewage lift stations stop.

While there could conceivably be a workable tech solution, it sure can't be ad hoc. Grid dispatchers need to be able to control all the components in the system to prevent damage to the system. That takes design standards that work in all the permutations the grid has to deal with. This is a big deal.

Then there is internal/external/regulatory politics. Utes are only 2-3% more efficient than governments. Ute management ditto. Ute lawyers are legion and largely intractable islands of "NO". Tech mgmt is generally well above average (to stay alive in such a dangerous enviro), but hamstrung by mgmt/legal. Result: slow moving, status quo enviro. (With all things considered, just might be the management style needed to just keep the lights on.)

While I do like the idea of cutting my e-bill with my own power, the idea of local energy gen/storage "only for local use" is a more tech, economic and practical answer.

Electricity is 50% more expensive than gasoline on a BTU basis. Energy sold back at wholesale is tiny compared to the direct benefit of local use that completely offsets buying more energy from the grid at retail. Why cut the ute in on the best part of the benefit of your investment when they are getting the indirect benefit of not building more gen plants? Both the consumer and the ute win this way without the complexity and any of the operational risk.

But cheap, local energy storage is the key to making at work. Probably in the range of $50/kWh storage all-in that can live quietly in your basement/garage for 10+ years with only minor care. We should be there in 3-5 years ... if we can keep the country together til then.
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this is way over ma head so it is going to take some time to digest all this.

ironchef · Aug 2, 2020

Trader200K said:
But cheap, local energy storage is the key to making at work. Probably in the range of $50/kWh storage all-in that can live quietly in your basement/garage for 10+ years with only minor care. We should be there in 3-5 years ... if we can keep the country together til then.
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Good post. I agree.

Local electricity generation is approaching breakeven but timing is not optimum unless storage is available. I would do it if cost effective local energy storage is available.

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virtual power plant, anyone observing

ggelitetrader000

ironchef