The press release for the OntarioEnergy Board's Market Surveillance Panel (MSP) Monitoring Report on Ontario'sElectricity Markets noted four recommendations, including: “an increase
in the frequency with which interties are scheduled, and the associated
frequency of demand and intermittent generation forecasts as well as
pre-dispatch schedules” and; "accelerating efforts to make wind generators
dispatchable ...” The MSP
report's information supports the claims (argued previously here), that the
depressed market prices, and dumping of excess generation, will not simply
continue, but grow over the next decade if Ontario's supply procurement
policies persist.
The Market Surveillance Panel (MSP) report delivers an analysis of
“low-price” hours (defined as the Hourly Ontario Energy Price – or HOEP – being
below $20/MWh). In comparing the Ontario
Energy Board (OEB) seasons, where winter begins November 1st and
summer begins May 1st, the report notes;
“The greater frequency of low-price hours in this year and in the past two years mirrors the general trend of lower Ontario demand and also reflects the increase to Ontario baseload supply, or generation that is offered like baseload supply (i.e. generators with fixed price contracts per MWh delivered). “
Baseload is difficult to define precisely in Ontario, as it has come to mean the electricity that the market needs to distribute because it is pre-purchased, regardless of demand. That generally includes nuclear units, a significant share of hydro generation capacity, a variety of, mainly natural gas, non-utility generators (NUGs), and generators contracted by the Ontario Power Authority (OPA) where the contract requires the grid to take all output (primarily wind and solar supply). Table 2.8 of the MSP Report (page 103) demonstrates the supply/demand relationship when the HOEP drops below $20/MWh. I've recreated much of that table, from existing data I've collected from available IESO sources; adding columns for wind data, and correcting a mistake in the April data on the original MSP Report.
Year | Month | Number of Low-Price Hours | Ontario Demand | Net Exports | Ontario Demand Plus Net Exports | Wind Production | Wind Capacity Factor | Corrected MSP Excess Low-Priced Supply | MSP Ontario Demand Plus Net Exports | Corrected MSP Total Supply |
2010 | 11 | 75 | 13,493 | 1,280 | 14,773 | 824 | 67% | 1,525 | 14,788 | 16,313 |
2010 | 12 | 62 | 14,522 | 2,085 | 16,607 | 720 | 56% | 590 | 16,692 | 17,282 |
2011 | 01 | 73 | 14,683 | 2,024 | 16,707 | 713 | 54% | 574 | 16,877 | 17,451 |
2011 | 02 | 27 | 15,769 | 1,002 | 16,770 | 995 | 71% | 477 | 16,779 | 17,256 |
2011 | 03 | 67 | 14,583 | 1,146 | 15,730 | 753 | 54% | 355 | 15,745 | 16,100 |
2011 | 04 | 211 | 13,550 | 1,473 | 15,023 | 722 | 52% | 656 | 15,072 | 15,728 |
515 | 14,433 | 1,502 | 15,935 | 788 | 59% | 696 | 15,992 | 16,688 |
Presumably the “excess low-priced supply” was either curtailed by
steam bypass (primarily at Bruce); by taking nuclear reactors, or NUG
suppliers, off-line; or, just as likely, by allowing water to flow freely
instead of diverting it through hydroelectric turbines (the tools available to
the IESO are shown here). The MSP Report notes
that frequently the ability to curtail wind production would eliminate some of
the negative, and low, pricing. What
caught my attention here was the high wind production during the low-priced
hours. It appears that during low-price hours the recently contracted wind production was slightly higher than the low-priced supply being curtailed.

Wind is particularly problematic due to its
erratic intermittent character, but it's really the proportion of supply that
the market is required to take, in scale to the overall market, that primarily determines the HOEP. Theoretically, a healthy market features a uniform price which is set by the last unit purchased. That price can only be meaninggully set where there is price competition, among suppliers. In Ontario market, the HOEP price is meaningless to the contracted generation - which is mostly referred to as "baseload" here. Adding to the confusion, some supply that is not run constantly, or on a must-take contractual basis, also has set prices; Ontario Power Generation (OPG) has regulated hydro assets meant to balance the grid and meet ramping demands throughout the day. I am grouping the data by baseload
generation as a percentage of Ontario's demand, not inclusive of all hydroelectric output. That makes my measurements conservative, and the data shows prices dropping, and net exports increasing, at slightly above 85% baseload to demand. As baseload exceeds 100% of demand, we expect the price to be low, or negative (depending on export markets) - these situations are known as Surplus Baseload Generation (SBG) periods to the system operator that predicts upcoming SBG conditions, in order to plan supply curtailment actions.


The number of hours where baseload exceeds Ontario
demand is set to rise rapidly through 2014, when refurbishment work on nuclear
reactors will temporarily slow the growth (in this model).
However, the continued growth of wind that is currently foreseen will
have a disproportionate impact on seasonal excess supply frequency. Because wind performs poorly in summer's heat
(average capacity factors in the low teens), removing nuclear capacity will temporarily reduce hours where baseload exceeds demand – but the higher capacity factors of
the shoulder seasons, and cooler periods, means that surplus baseload
generation will escalate rapidly with increasing wind capacity even with a lower nuclear contribution in Ontario's supply mix. It will simply move from primarily a problem from May-October (the OEB's summer period, and also the period of most SBG periods in 2009), to a year round issue.
None of this information is new to those of us familiar with the
data. My previous forecasting project concluded we are moving
towards a supply mix where approximately a third of all wind output will need
to be curtailed, dumped on export markets, or displace baseload hydro and/or
nuclear, a conclusion reached earlier in the year by Aegent EnergyAdvisors.
The Market Surveillance Panel's Report urges the IESO to speed up
the process designed to make, “wind generators
dispatchable,” which is a solution to the market pricing, but a solution that
is to pay suppliers without accepting supply from them. The IESO's process, SE-91, seems to have a worrisome focus, albeit one determined by
government policy. Central forecasting
may be a tool to determine how much to pay suppliers when their production is
curtailed due to a surplus of supply – but there seems less interest in
making the forecast accurate with the lead time, and frequency, required by the market design. Most of the 'stakeholders' are from the renewable energy industry, and as such
wouldn't have any foundation of knowledge in the requirements of a healthy market.
That won't be
much of an impediment in Ontario, where there isn't a healthy market, and
none seems likely in the foreseeable future.