Why are we limited to selling solar energy in real-time only?

[aesculus]

It's probably my confusion and I have not read the restrictions yet but I am not sure why we are restricted to only selling back solar power while we produce it.

It would seem we should be able to save our solar power in the PW and then play it back anytime during the day we want to just as long as we don't go over the rate we contracted for in our PTO.

So for instance I might create 20 kwh of solar in a day at a max rate of 4 kw/hour. I think I should be able to play back to PG&E at 4 kw/hr for 5 hours if I wanted to. Now reality says I would probably want to use some of that solar to offset my own use during peak so it would need to be calculated based on:

rate = (total solar produced - peak consumption amount) / hours in peak. Where rate cannot exceed your PTO. If you have stuff left over it just gets sent back after peak but no real gain or loss.

Does this make sense or am I missing something (like a rule?).

 

[power.saver]

Good question, and in CA soon you can (if not already approved by your utility). The CPUC ruled on this last year.

CPUC Decision here

 

[getakey]

you charge PW from solar during low rate. Then power house from PW during High rate and send solar to Grid at high rate. I don't see how you can make it better than that

 

[ohmman]

you charge PW from solar during low rate. Then power house from PW during High rate and send solar to Grid at high rate. I don't see how you can make it better than that

Well it depends on your TOU cutoffs, right? I frequently refill my PWs early in the morning and I'm left sending back solar during a less-valuable time. If I could dump more solar into the grid during peak (from my rooftop AND my PWs) then I'd make more "room" to charge in part-peak. The goal would be to only sell back during peak and never during the shoulders.

I looked at the NEM 2.0 documents but couldn't find anything specific. That doesn't mean it wasn't there, it just means I wasn't able to find it. The only thing I saw was something akin to “storage customers will be treated identically to non-storage customers” for the purposes of NEM. But @power.saver seems to have something of an answer above.

 

[ewoodrick]

The grid has enough "free" energy when the demand does down. No need to buy any.

 

[aesculus]

Good question, and in CA soon you can (if not already approved by your utility). The CPUC ruled on this last year.

CPUC Decision here

Thanks for this.

I wonder though if this will be a catch 22 that will force those of us who have EVA (PG&E) to adopt another plan since we will be changing and all grandfathering rules will go away. So once again we will probably have to do the math to see what works out the best. This could take the bite out of going to EVA2 if you can sell all your unused power back in peak.

 

[power.saver]

Well this decision allows for "no grid charging" or "no storage export" so you can do one or the other. The key will be for Tesla to get the PW certified under the new UL-1741 CRD (Certification Requirements Decision) standard so that they can be approved by the utilities for these use cases. I would choose "no grid charging" and take advantage of storage export to shift solar generation to the later peak period. This is also the only option that preserves the ITC requirement of only charging from solar, yet allows that stored energy to be exported later.

 

[Ampster]

The grid has enough "free" energy when the demand does down. No need to buy any.

That may be true in your neck of the woods, but in California during the neck of the duck curve our TOU rates are the highest. There is a lot of grid support battery systems being built here just to provide power during that time when power is needed the most. Most of those batteries will be charged during the days when solar is so plentiful it is being curtailed.

 

[troptop]

I would also like to empty my battery into the grid whenever I choose to, and I would choose to do it at peak time.

 

[charlesj]

Thanks for this.

I wonder though if this will be a catch 22 that will force those of us who have EVA (PG&E) to adopt another plan since we will be changing and all grandfathering rules will go away....

No free lunch, payment postponed and they will get you. After all that is why they are in business to make all $$$ they can.

 

[troptop]

I would also like to empty my battery into the grid whenever I choose to, and I would choose to do it at peak time.

Actually now that I ve learnt that SCE will only pay wholesale (like 0.03$ per kWh) for electricity I net produce, I see that its totally pointless being a net producer.

 

[charlesj]

Actually now that I ve learnt that SCE will only pay wholesale (like 0.03$ per kWh) for electricity I net produce, I see that its totally pointless being a net producer.

We have a tri county community power agreement for power generation only and they pay much more, closer to $.06/kWh or more. But, PG&E still gets a lot of revenue for everything else, delivery, profit, etc.
And, we are expanding to more counties or rather more counties want to join us.

 

[Ampster]

We have a tri county community power agreement for power generation only and they pay much more, closer to $.06/kWh or more. But, PG&E still gets a lot of revenue for everything else, delivery, profit, etc.

We have a similar CCA (Community Choice Aggregation) in Sonoma County that also serves Mendocino County. They just reduced their full retail dividend for excess generation but it is still better than PG&E. I was a net consumer of power but had a Net credit dollar balance. That washed out at True Up. Other than Non Bypassable Charges that is an optimum strategy for me.

 

[charlesj]

We have a similar CCA (Community Choice Aggregation) in Sonoma County that also serves Mendocino County. They just reduced their full retail dividend for excess generation but it is still better than PG&E. I was a net consumer of power but had a Net credit dollar balance. That washed out at True Up. Other than Non Bypassable Charges that is an optimum strategy for me.

Too bad these CCAs cannot buy the whole system, wires and all then the rates would begreat.
My son lived in Sana Clara for a while, saw his electric bill, couldn't believe how cheap his power was in total.
I called the provider, they own everything but the generation that is what PG&E buys at.

 

[miimura]

Too bad these CCAs cannot buy the whole system, wires and all then the rates would begreat.
My son lived in Sana Clara for a while, saw his electric bill, couldn't believe how cheap his power was in total.
I called the provider, they own everything but the generation that is what PG&E buys at.

That is the difference between a CCA and a municipal utility. Santa Clara and Palo Alto are examples of municipal utilities in the area.

 

[charlesj]

That is the difference between a CCA and a municipal utility. Santa Clara and Palo Alto are examples of municipal utilities in the area.

Yep, still too bad that is not what was negotiated if at all possible.

 

[Ampster]

Yep, still too bad that is not what was negotiated if at all possible.

CCAs are a result of deregulation started in 2000. Municipal Utilities have always been around so it was always possible for a municipal utility to be formed by buying out the infrastructure of a Investor Owned Utility. The reality in the marketplace is that kind of acquisition is not economically practical because of the huge unknowns of deferred maintenance. The hope of lower rates is probably a pipe dream because of that. Briefly during the bankrupcty of PG&E, the City/County of San Francisco discussed purchasing the assets of PG&E but that discussion went nowhere.
There was no need to to negotiate anything during deregulation discussions because that conversation was always about deregulating generation,