Public Utilities Reports

PUR Guide 2012 Fully Updated Version

Available NOW!
PUR Guide

This comprehensive self-study certification course is designed to teach the novice or pro everything they need to understand and succeed in every phase of the public utilities business.

Order Now

Solving The Crisis In Unscheduled Power

While NAESB and NERC struggle over the issue, North America steadily drifts toward unreliability.
Fortnightly Magazine - August 2004

this country's power, chronically disable governors, generate to a constant thermal rate, and over-generate in early morning hours for as little as -$100 a MWhr for a few hours to avoid $20,000-$30,000 in startup costs. This is reflected in chronic overgeneration such as by the Mid-Atlantic Area Council (MAAC) and Southwest Power Pool (SPP).

Also, the asymmetry of NERC-sanctioned payback-in-kind itself, like energy-only pricing, upward-biases frequency by rewarding over-frequency through both rewarding the over-generation that drives over-frequency and penalizing the under-generation that counters over-frequency. At the same time, it doesn't penalize under-frequency: It neither penalizes the under-generation or over-consumption that drives under-frequency nor rewards the over-generation that counters under-frequency. [NERC hasn't helped matters any by making its Disturbance Control Standard (DCS) since 1997 unidirectional to require deployment of reserves to recover only from underfrequency events, thereby incenting BAs to overgenerate to make the unidirectional recovery easier. DCS is mercifully being superseded in NERC's new draft Balancing Standard.]

Passing the buck to the interconnection creates a vicious reliability and financial/accounting circle. Rather than override the incentives for their constituent entities to over-generate, or bear the economic consequence of mindless IPP and merchant interconnection agreements, BAs "push" unscheduled power for free onto other BAs that are forced to take it for free by under-generating to keep frequency from drifting even higher and to keep their control performance from violating the NERC limit on frequency-deviation-weighted average contribution to frequency deviation. As a result either (A) inadvertent interchange accumulates as frequency creeps upward because the other BAs don't under-generate enough to keep up, or (B) inadvertent interchange stops accumulating but frequency creeps upward even more because BAs hurt their control performance by stopping frequency support or by unscheduled payback in kind of the accumulated power (notably in the Southeastern Electric Reliability Council). The Midwest ISO's Control Area Working Group has vigorously complained recently to NERC about this[11].

Patch-Up "Solutions" Backfire

ERCOT (the Electric Reliability Council of Texas) attempted to avert this problem by "killing the patient" only to create a new problem. The moment Texas introduced its market in August 2001, ERCOT centralized control by simply eliminating control areas (and therefore inadvertent interchange but not scheduling error) and thereby eliminating the frequency-stabilizing benefit of multiple entities' mutually offsetting control efforts. Average frequency deviation quickly widened in violation of ERCOT's ±23 mHz limit, forcing NERC to grant an indefinite waiver to ±30 mHz over some objections including mine, and ERCOT is now close to exceeding that limit, having experienced a May 2003 blackout along the way.

Meanwhile the Western Electricity Coordinating Council (WECC) through Bonneville has attempted a non-pricing "technical" solution to the problem of accumulation of unscheduled flows between BAs by invoking "automatic time-error correction" or immediately prompting extended unilateral payback of inadvertent interchange in staggered small increments. The small size of these increments keeps them from overly disturbing frequency but bears no relation to economic value. This automatically creates new inadvertent interchange to pay back the old inadvertent interchange, doubling the errors while removing only the accumulation motivation behind the frequency deterioration trend. The Western