How Alberta’s electricity grid almost failed – twice

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Alberta’s electricity grid needs better supply forecasting and more transparency to prevent the problems that led to an emergency alert in January and lights going out in April, according to the province’s power market watchdog.

A report released Tuesday by the Market Surveillance Administrator (MSA) examined how thousands of Albertans came to grapple with rolling blackouts in April – and why their phones, televisions and radios blared with an emergency alert in January, warning them to curtail power use to avoid catastrophic grid failure.

Widespread problems included inaccurate supply forecasts by the Alberta Electric Systems Operator (AESO), significant power exports to other jurisdictions and multiple gas-fired power plants all being offline at the same time.

Recommendations in the report include improving forecast data and transparency, and devoting sufficient resources to identify instances of suspected compliance contraventions by power generators. The MSA also called for generators to have better reasons to take their power plants offline – and for those reasons to be routinely audited by the AESO.

Marie-France Samaroden, the vice-president of grid reliability operations at the AESO, said that the operator has already implemented some of the improvements documented in the report, particularly when it comes to forecasting supply.

That includes how the temperature swings affect ice forming on wind turbines, which played a role in the April blackouts: “What we’ve come to learn in talking to our service providers since then is that a one-degree change in temperature could mean icing,” Ms. Samaroden said in an interview.

“If there’s even a chance of icing, it’s noted for us so that we can take that into account in our forecasts.”

She added that other changes will be considered as part of Alberta’s government-mandated market redesign, which is currently under way.

The province’s power market is unique in Canada in that it has no central or Crown power provider. Instead, private companies run the power plants that feed electricity into the grid. The AESO works with industry and the government to manage and plan that market.

The electricity landscape in Alberta – and indeed globally – has evolved significantly since the market was first designed. Goals to decrease greenhouse-gas emissions are increasingly counting on electrification, for example, putting more pressure on grids, and the move toward renewable assets that are more spread out means transmission systems are being decentralized.

Utilities Minister Nathan Neudorf said in a statement Tuesday that the report underscores the importance of improving the grid reliability through market reforms, and that the grid alerts in January and April “served as powerful reminders of the importance of having reliable electricity.”

Here’s why Alberta’s grid teetered on the brink – twice – according to the MSA.

Jan. 13

Leading up to the Jan. 13 alert, the AESO reckoned that supply to Alberta’s power grid would be tight, but manageable. But the province was in a deep freeze: As some communities felt historic low temperatures, demand skyrocketed; on Jan. 11, Alberta set a new record of 12,384 megawatts.

The day before, a 300-MW gas-fired plant in Grande Cache, owned by Maxim Power Corp., had tripped offline. Maxim initially thought the outage would be short-lived, but two days later, it was still stuck generating only around 70 MW.

Six other gas-fired plants also went offline or reduced supply on Jan. 12 and 13, and the extreme cold almost halved the amount of power coming from two of the province’s larger hydro assets. Imports were limited, too, as other jurisdictions in the West also experienced the brutal cold snap.

Alberta Premier Danielle Smith has frequently blamed the inconsistency of renewables as one of the governing factors of the January alert. However, the MSA report says that wind generation, while low, consistently met or exceeded forecasts made within 24 hours of the alert. It added that solar forecasts were “not relevant during the time of peak scarcity, which occurred after sunset.”

But even with multiple power plants offline, the AESO’s supply adequacy report (which rates how likely it is that the province will have enough power) was slow to signal increasing scarcity. In fact, it did not anticipate the tight supply conditions on Jan. 13 until the evening before.

Had the report signalled potential scarcity well before, it would have provided a better signal to the market and been less susceptible to sudden shifts based on forecast error and outages, the MSA said.

April 5

Unlike the January threat to Alberta’s power grid, high demand did not play into April’s rolling blackouts. Instead, the province’s first forced outages since 2013 boiled down to a rapid loss of supply.

The AESO knew there would be some gas-fired power plants offline that day, but thought its supply cushion put it in good shape to meet supply. Then the wind dropped off and unexpected mechanical failures hit various power plants, slashing the forecast supply cushion.

Ten gas-fired power plants experienced some level of planned or forced outage or capacity reduction leading up to the rolling blackouts. That included a planned outage at the largest power generator in the province, Shepard, a natural gas plant near Calgary owned by Enmax and Capital Power.

Once again, the AESO’s supply adequacy report was slow to react to deteriorating conditions. Through the morning of April 5, a series of outages in short succession compounded with existing outages to reduce the supply of gas-fired generation by approximately 4,000 MW. The grid was also producing around 400 MW less wind generation than expected, with forecasts not having taken the possibility of icing into account.

Just before 9 a.m., the AESO issued load shed instructions, which are controlled outages by electric utilities, to reduce grid strain. The result was rolling blackouts across Alberta.