California Renewable Feed-in-Tariff

[saladhawks]

I have been asked to review proposed changes to the California Public Utilities Commission Feed-in-Tariff, specifically the allowable size of PV systems that can be interconnected to distribution systems. Note that these proposed changes are under consideration as a result of increasing the Renewable Portfolio Standard (RPS) to 33% w/o requiring the construction of new transmission lines.

Previous review limited the max. size of DG (all generators) resources to 15% of the peak load at the point of interconnection. Consideration is being given to increasing the max. size limit of PV only systems to 30% of the peak load at the point of interconnection. The rationale is that peak PV output coincides to a large degree with the peak loading on distribution feeders.

It does not appear that any significant testing / analysis of this proposed change has been made to date. It sounds reasonable to me. Any thoughts?

 

[redfurry]

Why is the number so low, even at 30%?

I know that in Sarnia, Ontario they've connected around 20MW of solar PV to a feeder (which is probably much larger than the peak load on the feeder).

As long as voltage regulation isn't a problem, and as long as there aren't any islanding problems, they should be able to generate as much as they like without any adverse effects on the system. PV inverters generally make for pretty good citizens on a distribution feeder.

 

[davidbeach]

PV inverters generally make for pretty good citizens on a distribution feeder.

Never had to deal with voltage regulation on a long, multi-branched rural distribution feeder, have you? Try putting more PV on one branch than the entire circuit load and look at what happens to the voltage regulation for other branches.

 

[redfurry]

Quote (davidbeach):
"Never had to deal with voltage regulation on a long, multi-branched rural distribution feeder, have you?"

Actually I have, which is why I noted that the only major obstacle to installing PV is voltage regulation.

On urban feeders voltage regulation just isn't a problem and even large installations of PV pose very few issues.

On a stringy rural feeder, no amount of generation is safe and the effects on voltage will vary dramatically depending on existing load and generation location.

I dislike the kind of rule where the regulator says that generation equal to X% of load is allowed.
As the saying goes: One size fits all ... badly.

 

[alehman]

The limit seems strange to me also. In my area there is no specific limit, so long as it doesn't cause power quality or voltage problems. But then we don't have a lot of PV in Kansas.

Alan
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"It’s always fun to do the impossible." - Walt Disney