RKCRLR
Active Member
The same entity that is would be paying for the massive utility solar arrays they're proposing. Divert that money to storage. They could also go the old fashioned route and use pumped storage hydropower.
Last edited:
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
CPUC NEM 3.0 discussion
- Thread starter jjrandorin
- Start date
RKCRLR
Active Member
Obviously when forecast supply exceeds forecast demand, the system is in an overgeneration condition. I don't see why you put the onus on solar and wind. Now if solar and wind are the most easily curtailed sources (fastest ramp up and down), and you've already curtailed the other sources that you can curtail while ensuring enough supply after the sun goes down, then you curtail solar and wind. But let's not say that the overgeneration is solar and wind's "fault," we could just as easily say it's the nuclear plant's fault for not being curtailable.
Different supplies have different characteristics, and obviously CAISO has a balancing act to do.
Cheers, Wayne
Maybe Wayne can answer this, but it looked like "a lot" of curtailment.
It seemed like May was/is a bad month, alot of sun but not so hot we are on A/c.
So it looked like curtailment for the month was 320,000 mwh mega watt hours.
Divide by 30, I guess. About 10,000 mega watt hours a day.
Well, peak demand is like 20,000 mega watts.
Does that mean at, like noon that demand that 10,000 mega watts of solar has to be curtailed for an hour?
That's almost the capacity of solar not being curtailed. The amount of natural gas at that point is only 4,000 mw.
Maybe I have the MWh to MW confused.
But sheesh. Maybe we need that solar in a month where demand is like 40,000 MW. Curtailment sounds sort of bad, its really we have solar in reserve but historically don't need it in spring.
But its almost like now is when we are overbuilding. Now.
May is a bad month for the reason that you noted and the fact that the snow pack is melting and therefore hydro generation output is increasing. The solar and wind must be heavily curtailed because everything else that can be curtailed is curtailed.
They are not curtailing solar and wind because they do not like it, they do it because they have no other options.
I am sure that the curtailments are for several hours each day with weekends and holidays being worse due to lower loads. So it is probably somewhere along the lines of 1000/MW to 2000/MW per hour. That would be a guess. Some hours more some hours less. If it is for more hours than it would be less hourly volume of course.
Baloney. PG&E NEM-PS billing has the usage data down to 5 minute increments. It isn't listed, but it is there in order to calculate the total imports for NBC on a finer scale than an hour which is what they let you download.
Now going to real time pricing is a two edge sword. If you have control to be able to charge an EV or fire up a crypto miner to consume the energy it might be useful, but as a lot of Griddy Energy customers found out in Texas you could end up paying a lot more.
Instead of this stupid proposal for a fixed monthly fee per kW of inverter capacity, they could make the NBCs a function of the maximum amount of power you export to the grid (say the peak you hit every day, for a 30-day window, for whatever window gives the highest value) in any given year, similar to a demand charge for large industrial customers, but in reverse. The higher the maximum export, the higher the NBCs. So if you build a very large, 50 kW solar system without storage, intend to push large amounts of power to the grid during midday in the summer time, and then draw huge amounts of power from the grid all winter to offset it, you're going to pay very large NBCs. However if you build a large 50 kW solar system that matches your demand quite well, and you only exported 1 kW on average at midday, well, you're not going to pay very much in NBCs. If you happen to never export power because you're always consuming more than you're producing, then you don't pay any NBCs at all. Add storage, or put in a smaller system, reduce your maximum exports, and reduce your NBCs.
Where are you getting your real-time price signal from so you can fire up your crypto rig? How are they billing when you are under a NEM contract?
When you figure that out go ahead and fire up that electric range and fry some of that baloney.
The utility may well have usage data but people can't sit around all day and day-trade their own electric usage.
As it is the IOUs have pricing which encourages anyone to use energy during non peak and it doesn't affect the demand curve at all.
You are moving the goal posts as you said that there wasn't a "billing mechanism". The CALISO site has a page with current pricing by generator, that might not be the right choice, but this information is available and can be transmitted to customers that want to do this in multiple ways. I've heard that some places in the EU have in home simple displays showing real time costs. Discrete device, app, SMS texts for humans and an API for machine-to-machine actions. For example the EV charger connected to the internet uses the API to monitor pricing, when a level is hit it starts to charge and stops when the limit is exceeded. Smart Thermostat (not in @holeydonut or @h2ofun house) turns up/down the temperature based on the pricing.
This isn't a new concept.
They just want everyone to pay them what they would have paid them with no system.
Forget what your system costs. If you put in a 12 kw system that throws off about 1,800 kwh a month, and that is your usage......
Then.
You will directly offset about 600.
Of the 1200, you send that much to the grid, but only get credit for 120, so basically you are, sort of 720 "ahead." (that's what a 1 to 10 credit ratio means)
That 720 is non peak. Your 12 kw is charged $96. If you had just bought 720 non peak kwh from them the charge would have been like $126
$126 minus $96 is about $30 bucks.
There are probably some other charges in there which eat into or eliminate the $30.
I mean, there is no pay back. I don't know how they get a "ROI" --- if you save $20 a month or $240 a year your $24,000 system pays for itself in 100 years.
There isn't a billing mechanism under the current NEM contracts and current tariff rates. You can't get paid or pay the real-time price. They might have all those things somewhere in the EU, I was talking about here. You are calling my statement baloney while describing something that does not exist.
RKCRLR
Active Member
Again, you are moving the goal posts, so baloney. The original post was about a NEW way of pricing for times with excessive renewables which has nothing to do with current contracts or current tariffs.
A billing mechanism is a way to charge a customer and PG&E systems maintain data down to at least 5 min increments and they have their own real time pricing rates, so IMHO the mechanism exists to bill customers even if the actual implementation hasn't been made yet for real time pricing.
ERCOT had this half assed system where people would be charged based on the market prices, but they didn't actually know what the prices were in real time. That really defeats the purpose of market pricing because demand isn't being controlled by pricing as it should be.
Maybe a matter of semantics but they curtail solar and wind because it is the easiest and cheapest option.
Looking at the numbers it seems like they curtail 2-3 days worth of utility scale solar production in a bad month, so they are still using ~>90% of the solar production in that month. This doesn't seem like a bad thing to me as the rest of the days/months the full solar production is still used. The bigger issue is controlling the ramp in net demand after the sun goes down, although I would think that could be mitigated somewhat by further curtailment of the solar production if necessary. Obviously ESS would help but it is expensive.
Not sure how the discussion got off on this tangent other than to say the marginal value of a kWh mid-day certain times of the year is 0 or less. I guess also to the point that residential solar is difficult to curtail unless your willing to change the grid frequency, but I think we are more than a decade away from where residential solar is a really significant issue here even with the current incentives.
RKCRLR
Active Member
One would think that the most cost effective way with dealing with excess power production would be to store it. The infrastructure and everything is already there, you're probably still paying for most of the power whether or not you are taking it. Its sort of like free energy. If the problem is the contracts they entered then that can be resolved in the future.
Similar threads
- Locked
