By Amanda Durish Cook

MISO Under New Load Forecasting Method

CARMEL, Ind. — MISO will this year draw on three sets of contributors to create its load forecast for 2020 transmission planning.

The RTO said last week it has moved ahead with a proposal to have Purdue University’s State Utility Forecasting Group (SUFG) and consulting firm Applied Energy Group (AEG) work with 20-year forecasts provided by load-serving entities.

By June, MISO will have its first load forecast based on the four 15-year future scenarios it uses annually in its Transmission Expansion Plan. Throughout last year the RTO had been examining how it could coordinate its annual load forecasting with its annual transmission planning.

Until the compromise was struck late last year, MISO had put a temporary hold on ordering more independent load forecasts from the SUFG. LSEs will now develop 20-year base load forecasts that include monthly predictions for energy and non-coincident peaks, which the SUFG will use in its state-by-state forecast.

The LSEs will also compile demand-side data separately for AEG, which will use the figures to develop demand-side management potential used in RTO planning. (See MISO Presents Load Forecasting Compromise.) MISO plans to compile and check forecast data and serve as a liaison between all parties.

“The original goal of this merged proposal is to provide more clarity, consistency and efficiency to load forecasting,” MISO adviser Ling Hua said at a Feb. 13 Planning Advisory Committee meeting.

MISO will begin building models in May for resource forecasting as part of MTEP 2020.

MISO’s 140-plus LSEs received load forecast surveys in mid-January and were expected to respond by Feb. 15. The RTO said it will next month check the submitted data for completeness.

Veriquest Group’s David Harlan said he still didn’t see how MISO’s new process will translate into new load shapes.

Hua said the RTO isn’t aiming for new load shapes for 2020’s MTEP, just a more detailed forecast.

“We’re envisioning that this is going to be an incremental step. For this time around, we’re going to implement more granular load data, but updated load shapes will be for the next time around,” she said.

Hua said questions on the new process can be directed to loadforecast@misoenergy.com.

MISO to Process Hybrid Interconnections Under 1 Form

MISO plans to allow generating facilities using more than one fuel source — or hybrid resources — to submit a single request to join the interconnection queue, pending FERC approval.

The current Tariff prohibits customers from designating two fuel types on an interconnection request, but MISO’s proposal will allow them to submit a hybrid generating interconnection on a single application.

The revised interconnection request form will allow interconnection customers to “check all that apply” for fuel sources, including a line for storage, a change that will ease an “administrative burden,” MISO said. Hybrid interconnection requests are technically already permitted by the RTO, just under separate applications.

“It’s the same policy, just a practice change,” Resource Interconnection Planning Manager Neil Shah said.

MISO plans to file the proposal by the end of the month.

The RTO also plans to make a similar interconnection Tariff filing this month, clarifying that it allows two facilities to share a single point of interconnection, provided it, both facility owners and the transmission owner sign an agreement. (See MISO Queues up Interconnection Options.)

Draft Rules Discourage Weak Grid Interconnections

In an effort to ward off inverter-based instability, MISO is firming up rules requiring inverter-based generators seeking to enter the interconnection queue to provide a specific set of calculations and documentation.

The RTO has already drafted new Business Practices Manual language, although stakeholders at a Feb. 12 Planning Subcommittee meeting urged it to take a more active role in calculations before finalizing rule changes. (See MISO Moving to Head off Inverter-based Instability.)

Under current practice, interconnection customers must submit short-circuit ratios (SCRs) to MISO before the close of the first decision point in the interconnection queue, while TOs must calculate and report fault megavolt-ampere values to those customers. In addition, the customers must also either submit manufacturer documentation showing that their generation can steadily operate or an Electromagnetic Transients Program-based study report showing stable operation for the inverter-based resource.

Clean Grid Alliance’s Rhonda Peters argued that the RTO isn’t allowing interconnection customers enough time in the queue to pull together all the required documentation.

“It’s not cheap to hire a consultant to put together a model,” Peters added.

She also suggested that MISO calculate the SCRs for customers, given the lack of a standard method for calculating. All interconnection customers should be working from the same set of assumptions, she said.

Other stakeholders urged MISO to take the reins in crafting SCR values at the beginning of the definitive planning phase of the queue.

Shah said MISO can examine taking a more involved role in calculating the SCR values, adding that the SCR is a simple calculation, if customers are working off accurate grid information.

“To my understanding, calculation of the SCR takes no more than 20 minutes if you have the right models in place,” Shah said.

The RTO asked for more stakeholder feedback on the draft rules through Feb. 26.

MISO Proposes Virtually Unchanged MTEP 2020 Futures

MISO expects current policy and economic trends to persist from 2020 to 2035, suggesting only slight changes to the four futures that guide the planning behind the MTEP.

“MISO believes there has been minimal changes since the MTEP 19 futures, and we’re in the same place trend-wise where we were last year,” Planning Manager Tony Hunziker said during the Feb. 13 meeting.

The RTO in 2017 began developing 15-year futures meant to be reused over multiple annual planning cycles after staff noticed little year-to-year change in forecasted trends. (See MISO to Recycle Tx Planning Scenarios for 2019.)

MISO’s four 15-year futures include a base case/limited fleet change scenario, continued fleet change future, an accelerated fleet change future, and a future in which distributed and emerging technologies become more widely used in the RTO’s footprint.

For MTEP 2020, MISO plans a simple refresh of its underlying data, including new capital cost data, demand forecasts, fuel forecasts, generation retirement projections, renewable targets and updated statistics on the interconnection queue, Hunziker said. The futures will be discussed again in April and finalized in June.

Veriquest’s Harlan said he wanted MISO to discuss the possibility of an additional future during the workshop, asking for a fifth future that illustrates an increasing reliance on imports in local resource zones and the closing physical gap between generation and load as gas and coal units retire. Other stakeholders asked that the RTO start including findings from its ongoing renewable integration impact assessment in MTEP futures. (See Study: MISO Grid Needs Work at 40% Renewables.)

MISO has said it may consider working on completely new future scenarios for MTEP 2021.