NEW ORLEANS — Competitive transmission, hurricane forecasts and maximum generation alerts were among the topics at the Gulf Coast Power Association’s MISO South regional conference Feb. 8. Here’s some of what we heard.

Bear Bullish on Hartburg-Sabine Project

MISO CEO John Bear predicted the Hartburg-Sabine Junction market efficiency project will produce better than a 1.35:1 benefit-cost ratio, although he acknowledged it did not have “broad” stakeholder agreement.

“I do think it’s the right answer. I think it really does help us with our reliability issues in the South, with load pockets; making sure that we can support the growth that we need from an economic standpoint, from a reliability standpoint, from a resiliency standpoint. It checks all those boxes.”

The RTO issued a solicitation for competitive bids on the estimated $130 million, 500-kV project in eastern Texas last week. (See Hartburg-Sabine Tx Project Open for Bids.)

GCPA Executive Director Tom Foreman asked Bear why there hasn’t been more transmission built through MISO to deliver SPP’s growing wind generation to the east.

“The economics have to be right for both parties,” Bear responded. “There’s a lot of analysis underway to look at that, but we’ve got a lot of work to do to make sure it makes the most sense. With the amount of wind that’s on the system today and low gas prices, more wind doesn’t necessarily lower LMPs.

“Trying to understand how to operate [the SPP] seam reliably and efficiently is also really important,” Bear added. “We don’t have as mature a relationship working with SPP on that seam because it hasn’t been [there] as many years” as MISO’s seam with PJM.

Moving Beyond the ‘Cone of Uncertainty’

Chris Hebert, TropicsWatch manager for StormGeo, said the “cone of uncertainty” developed about 15 years ago to forecast hurricanes’ paths is no longer the state of the art.

Hebert explained that the cone is actually constructed by joining the edges of a series of circles, each representing a 67% probability of the storm passing through. As forecasting has improved, the cones have gotten narrower.

But that can lead to dangerous complacency, he said, noting that Hurricanes Katrina (2005), Ike (2008), Joaquin (2015), Matthew (2016) and Harvey (2017) strayed outside their predicted paths. “Being outside the cone doesn’t mean you’re safe,” he said.

Hebert said a consensus of models is better at indicating the current uncertainty and potential impact of storms.

Judith Curry, president of the Climate Forecast Applications Network, said she used “ensembles” of models and Monte Carlo sampling to help Florida Power & Light pre-position utility crews before Hurricanes Hermine (2016), Matthew and Irma (2017).

Curry said it’s too early to blame climate change for affecting either storm intensity or frequency. “It’s impossible to separate what might be global warming from natural variability,” she said, adding that data on warming’s impact on storms are unlikely to be clear until about 2050.

The consensus is that warming will cause an increase in storm intensity — including more Category 4 and 5 hurricanes — but that the overall number of tropical cyclones will decrease, Curry said. “If those predictions are true, we may have smaller overall impacts from hurricanes later in the century. But this is all very speculative. The climate models are nowhere near good enough to actually predict this,” she said.

Sallie Rainer, CEO of Entergy Texas, discussed her utility’s response to Hurricane Harvey, which dropped 50 inches of rain in its service territory over eight days in late August and early September, flooding six major substations.

The experience is leading the company to seek more information about local watersheds, she said. “Understanding where those bayous and tributaries will dump the water when we’ve had 50 inches come in … and being able to lay that over our topology and our equipment [will show] what we need to protect … if we need to raise control houses, put floodwalls up.”

Entergy Talks Tax Savings

Phillip May, president of Entergy Louisiana, said the reduction in the federal corporate income tax from 35% to 21% will result in about $100 million in annual savings for the company’s customers. “We believe tax reform will have significant and meaningful benefits to our customers,” he said.

Max Gen Events

During a discussion on MISO’s maximum generation events in April 2017 and January 2018, Independent Market Monitor David Patton reiterated his call for the RTO to exercise more control over the scheduling of maintenance outages.

Patton said an excessive number of planned outages contributed to 22 days of conservative operations in load pockets in spring 2017, including three days of maximum generation alerts in April 2017, which included an April 4 emergency max gen event following the loss of a large nuclear unit in the South during a period of high load.

“It would have been great if we’d started our outages earlier or spread them out, because we had more capacity than we knew what to do with in the peak period and then we scheduled ourselves into an emergency in terms of the outages in March and April,” he said. Under its Business Practices Manual, MISO can only “recommend [an outage] schedule that maintains system security and minimizes adverse impacts.” (See MISO South Outages Worry RTO, Monitor.)

Patton said the biggest problems occur when transmission and generation outages are scheduled simultaneously in the same area. “If you take a major line out of service and then you take a large generator that played a key role in relieving the flows into that area, you can end up with congestion that’s very difficult to manage and generates a lot of cost quickly.”

Patton, however, said the South would have been in worse shape had it not been part of MISO. “Having MISO operating the integrated region between the South and Midwest increases reliability in both regions,” he said.

He recommended that MISO purchase capacity in four seasonal tranches to ensure sufficient generation year-round and give resources options on when to accept capacity obligations. Load-modifying resources — demand resources and behind-the-meter generation that provide capacity — shouldn’t be summer-only, he said.

Most LMRs called up for the first time in a decade during the April 4 event failed to respond properly to scheduling instructions. (See 4 LMRs Face Penalties after MISO Max Gen Emergency.)

Richard Doying, executive vice president of operations, said MISO staff are preparing a white paper on whether it should be planning seasonally rather than its traditional focus on the summer peak. He noted that LMRs represent almost 10% of the RTO’s fleet.

— Rich Heidorn Jr.