Monday, March 2, 2020

A Frequency Control Ancillary Services story

Frequency Control Ancillary Services (FCAS) has not been the hot topic in public discussions of the electricity sector, but recent events in South Australia made "Don't Forget About FCAS!", by Allan O'Neil at WattClarity, the most interesting article I've read in some time.

The grid in South Australia has one major interconnector to another grid, which was taken out of service by a storm on January 31st, 2020, essentially "islanding" the state's system. I first noticed discussion on events from a tweet listing generators (mostly wind) that would be "ramped down and constrained to zero" when "operational demand in South Australia falls below 800 MW". Operational would mean demand from the grid, which in South Australia is lessened significantly during the day as 1 in 3 houses are reported to have solar panels. For perspective, average consumption in the state is less than 1400 MW; demand following below 800 MW has been rare but occurences are growing (now 200+ a year).

The state was better prepared for the loss of transmission the year than it had been in 2016, when it suffered a full blackout. In part driven by changes made after the 2016 blackout the state has become a net exporter. Operational system peaks have been around 3,000 MW (now occurring after solar's productive hours), and the state's gas capacity  (~2700 MW) is capable of meeting about 90% of that. The state also has about 2,700 MW of wind capacity, so stories coming out claiming the state survived the loss of the interconnector include phrases like "renewables saved the day" - although we know many wind generators were constrained off, natural gas climbed to 60% of production (it's usually about 50%), and demand wasn't high (averaging ~1,250 MW).

All sorts of interesting aspects to be explored, but for me the most interesting was this: during the loss of the interconnector FCAS became more valuable in South Australia than "energy" (the production from generators).

There's something in the Watt Clarity article for many different audiences - including battery performances from both the large grid-connected units and the appearance of FCAS being provided by aggregators of residential units.





spreadsheet

Friday, February 28, 2020

California utility changes efficiency metric to "avoided carbon"

From the Sacramento Municipal Utility District (SMUD):
The new metric expected to encourage building electrification
The SMUD board voted to change the metric by which it measures the progress of its energy efficiency investments, switching from energy savings to avoided carbon emissions, making it the first entity in the United States to do so. The change will enable SMUD’s energy efficiency programs to focus investments on those that reduce carbon emissions at the lowest possible cost to customers and clear the way for expanded investments in building electrification alongside traditional efficiency approaches. 
“With carbon as our new measuring stick, helping our customers go all-electric will be as important as helping them use less energy,” said Rachel Huang, director of Energy Strategy, Research and Development. “Additionally, because this change encourages electrification, our customers will benefit from improved indoor air quality and reduced monthly energy bills.”
Under SMUD’s recently-adopted Integrated Resource Plan, building and transportation electrification are key strategies to achieve net zero carbon emissions by 2040. Switching to avoided carbon as a metric for energy efficiency investments aligns SMUD’s energy efficiency program with its net zero-carbon emissions goal...
 Good to see a utility focus on selling their product with the intent of it being a net good.

For my opinion on traditional conservation, or efficiency, programs, see "f in efficiency: Free-riders of the soft path"