Tag Archives: capacity market

ERCOT has the peak period scarcity price too high

The freeze and resulting rolling outages in Texas in February highlighted the unique structure of the power market there. Customers and businesses were left with huge bills that have little to do with actual generation expenses. This is a consequence of the attempt by Texas to fit into an arcane interpretation of an economic principle where generators should be able to recover their investments from sales in just a few hours of the year. Problem is that basic of accounting for those cashflows does not match the true value of the power in those hours.

The Electric Reliability Council of Texas (ERCOT) runs an unusual wholesale electricity market that supposedly relies solely on hourly energy prices to provide the incentives for incenting new generation investment. However, ERCOT is using the same type of administratively-set subsidies to create enough potential revenue to cover investment costs. Further, a closer examination reveals that this price adder is set too high relative to actual consumer value for peak load power. All of this leads to a conclusion relying solely on short-run hourly prices as a proxy for the market value that accrues to new entrants is a misplaced metric.

The total ERCOT market first relies on side payments to cover commitment costs (which creates barriers to entry but that’s a separate issue) and second, it transfers consumer value through to the Operating Reserve Demand Curve (ORDC) that uses a fixed value of lost load (VOLL) in an arbitrary manner to create “opportunity costs” (more on that definition at a later time) so the market can have sufficient scarcity rents. This second price adder is at the core of ERCOT’s incentive system–energy prices alone are insufficient to support new generation investment. Yet ERCOT has ignored basic economics and set this value too high based on both available alternatives to consumers and basic regional budget constraints.

I started with an estimate of the number of hours where prices need the ORDC to be at full VOLL of $9000/MWH to recover the annual revenue requirements of combustion turbine (CT) investment based on the parameters we collected for the California Energy Commission. It turns out to be about 20 to 30 hours per year. Even if the cost in Texas is 30% less, this is still more 15 hours annually, every single year or on average. (That has not been happening in Texas to date.) Note for other independent system operators (ISO) such as the California ISO (CAISO), the price cap is $1,000 to $2,000/MWH.

I then calculated the cost of a customer instead using a home generator to meet load during those hours assuming a life of 10 to 20 years on the generator. That cost should set a cap on the VOLL to residential customers as the opportunity cost for them. The average unit is about $200/kW and an expensive one is about $500/kW. That cost ranges from $3 to $5 per kWh or $3,000 to $5,000/MWH. (If storage becomes more prevalent, this cost will drop significantly.) And that’s for customers who care about periodic outages–most just ride out a distribution system outage of a few hours with no backup. (Of course if I experienced 20 hours a year of outage, I would get a generator too.) This calculation ignores the added value of using the generator for other distribution system outages created by events like a hurricane hitting every few years, as happens in Texas. That drives down this cost even further, making the $9,000/MWH ORDC adder appear even more distorted.

The second calculation I did was to look at the cost of an extended outage. I used the outages during Hurricane Harvey in 2017 as a useful benchmark event. Based on ERCOT and U.S. Energy Information Reports reports, it looks like 1.67 million customers were without power for 4.5 days. Using the Texas gross state product (GSP) of $1.9 trillion as reported by the St. Louis Federal Reserve Bank, I calculated the economic value lost over 4.5 days, assuming a 100% loss, at $1.5 billion. If we assume that the electricity outage is 100% responsible for that loss, the lost economic value per MWH is just under $5,000/MWH. This represents the budget constraint on willingness to pay to avoid an outage. In other words, the Texas economy can’t afford to pay $9,000/MWH.

The recent set of rolling blackouts in Texas provides another opportunity to update this budget constraint calculation in a different circumstance. This can be done by determining the reduction in electricity sales and the decrease in state gross product in the period.

Using two independent methods, I come up with an upper bound of $5,000/MWH, and likely much less. One commentator pointed out that ERCOT would not be able achieve a sufficient planning reserve level at this price, but that statement is based on the premises that short-run hourly prices reflect full market values and will deliver the “optimal” resource mix. Neither is true.

This type of hourly pricing overemphasizes peak load reliability value and undervalues other attributes such as sustainability and resilience. These prices do not reflect the full incremental cost of adding new resources that deliver additional benefits during non-peak periods such as green energy, nor the true opportunity cost that is exercised when a generator is interconnected rather than during later operations. Texas has overbuilt its fossil-fueled generation thanks to this paradigm. It needs an external market based on long-run incremental costs to achieve the necessary environmental goals.

CAISO doesn’t quite grasp what led to rolling blackouts

Steve Berberich, CEO of the California Independent System Operator, assessed for GTM  his views on the reasons for the rolling blackouts in the face of a record setting heat wave. He overlooked a key reason for the delay on capacity procurement (called “resource adequacy” or RA) and he demonstrated a lack of understanding of how renewables and batteries will integrate to provide peak capacity.

Berberich is unwilling to acknowledge that at least part of the RA procurement problem was created by CAISO’s unwillingness to step in as a residual buyer in the RA market, which then created resistance by the CCAs to putting the IOUs in that role. RA procurement was delayed at least a year due to CAISO’s reluctance. CAISO appears to be politically tone-deaf to the issues being raised by CCAs on system procurement.

He says that solar will have to be overbuilt to supply energy to batteries for peak load. But that is already the case with the NQC ELCC just a fraction of the installed solar and wind capacity. Renewable capacity above the ELCC is available to charge the batteries for later use. The only question then is how much energy is required from the batteries to support the peak load and is that coming from existing renewables fleet. The resource adequacy paradigm has changed (more akin to the old PNW hydro system) in which energy, not built capacity is becoming the constraint.

Chasing gold at the end of the rainbow: how reliance on hourly markets doesn’t spur generation investment


Commentators have touted the Texas ERCOT market as the epitome of how a fully functioning hourly electricity market can deliver the economic signals needed to spur investment in new capacity. They further assert that this type of market can be technology neutral in what type of investment is made. The Federal Energy Regulatory Commission (FERC) largely adopted this position more than two decades ago when it initiated restructuring that led to the creation of these hourly markets, including the California Independent System Operator (CAISO). And FERC continues to take that stance, although it has allowed for short term capacity markets to backfill for reliability needs.

But now we hear that the Texas market is falling short in incenting new capacity investment. ERCOT which manages the Texas grid projects near term risks and a growing shortfall at least to 2024. At issue is the fact that waiting around for the gambler’s chance at price spike revenues doesn’t make a strong case for financing capital intensive generation, particularly if one’s own investment is likely to make those price spikes disappear. It’s like chasing the gold at the end of the rainbow!

This is another sign that hourly markets are not reliable indicators of market value, contrary to the view of proponents of those markets. The combination of the lumpiness of generation investment and the duration of that generation capital, how that new generation undermines the apparent value in the market, and the lack of political tolerance for failures in reliability or meeting environmental targets require that a much more holistic view of market value for these investments. The value of hedging risk, providing cost stability, improving reliability and resilience and reducing overall portfolio costs all need to be incorporated into a full valuation process.