Texas electric grid serves record-high power demand

Energy Information Administration ^ | AUGUST 17, 2015 | Energy Information Administration

[thackney]

During the recent heat wave in Texas, the Electricity Reliability Council of Texas (ERCOT), the operator of the electric grid covering most of the state, set a new record for electricity use when demand for electricity reached 69.8 gigawatts (GW) between 4:00 p.m. and 5:00 p.m. on August 10. ERCOT has been able to handle this extremely high demand without any system emergencies. In its summer 2015 reliability assessment, the North American Electricity Reliability Corporation (NERC) had forecasted a higher reserve margin for Texas's electric grid this summer (16.24%) compared with previous years (14.98% in 2014). Reserve margins reflect the amount of available generating capacity in the absence of unplanned outages at projected peak system demand. Reliability planning helps to ensure that there are enough electricity supply and transmission resources to meet demand even if there are unexpected outages of generation plants or transmission lines. Although sustained high summer temperatures and strong population and economic growth pushed peak demand higher than forecast, the grid has performed as expected.

In August 2011, ERCOT declared several emergencies in an effort to reduce electric demand. Rolling power outages were avoided because load curtailment was carried out through demand response and interruptible load contractual agreements, calls for voluntary conservation, and execution of short-term contracts that brought four generators back from nonoperating status. Since then, grid operators have worked to better ensure reliability in ERCOT.

Unlike all other U.S. regional transmission organization wholesale electricity markets, ERCOT has neither a capacity market nor a requirement that energy suppliers build or purchase reserve capacity to meet unexpected supply shortages. Instead, ERCOT allows wholesale prices to rise relatively higher than in other markets during system emergencies. This encourages consumers to conserve energy while relying on high wholesale electricity prices to spur investment in generation resources.

Price caps are instituted in wholesale markets so that generators cannot charge unreasonable prices when power is scarce. ERCOT price caps have risen from $1,000 per megawatthour ($/MWh) at the 2001 start of retail competition to $9,000/MWh since June 1 of this year. ERCOT has made efforts to encourage market transparency and disclosure to discourage companies with market power from overcharging during system emergencies. ERCOT day-ahead zonal prices were near $2,250/MWh during the hour of greatest demand on August 10.

ERCOT has taken additional price-related actions to encourage investment in generation. These actions include adding a premium to real-time prices when resources are scarce based on the outage risk and the lost value to consumers of an outage, establishing price floors for emergency response services to keep prices from falling during emergencies, and allowing generators to earn a capacity price for reserving a limited amount of capacity to provide ancillary services.

ERCOT has also added more generating capacity and demand response. Since last year's NERC summer assessment, more than 6 GW of new generating capacity, mostly natural gas and wind, has been installed in ERCOT. Year-to-date through August 11, Texas used a record-high 4.5 billion cubic feet per day of natural gas to help fuel the state's expanded power generation needs. ERCOT also has several types of demand-response programs that allow participants to bid in a price for either voluntarily using less electricity or by running distributed generation resources. Together these demand-response programs represent 3.4% of the ERCOT total internal demand forecast.

[thackney]

[trebb]

Must be a lot of new electric vehicles plugging in.....

[knarf]

Wec are the best at everything

[thackney]

ERCOT says while the summer temperatures are partly attributable to the increase, the state’s explosive population growth is the real driver.

“A large part of the demand we’re seeing is customer growth over the last few years,” said ERCOT COO Brad Jones last week.

http://www.rtoinsider.com/ercot-demand-records-17050/

[thackney]

Statewide population change
2010 Population: 25,145,561
2014 Population: 26,956,958
Population change: 1,811,397
Percent change: 7.2%

http://www.texastribune.org/2015/05/21/interactive-texas-population-growth-2010-2014/

[ProtectOurFreedom]

So how much of that came from dearly beloved windmills?

[thackney]

At the time of the peak, not very much.

2,242 MW
http://www.ercot.com/content/gridinfo/generation/windintegration/2015/08/Wind%20Integration%20Report%2008-10-2015.pdf

Peak wind output that 24 hours was 8,608 MW shortly after midnight.

We are averaging about 10% generated by wind over the year.

[Cletus.D.Yokel]

Oh, my!
For grins and giggles:

[crusty old prospector]

I’m doing my part to drive up natural gas prices.

[nascarnation]

Wouldn’t solar panels be a better choice in areas where the high demand period is summer air conditioning?

[thackney]

Solar is nice for matching timing of AC peak loads, but not so nice in being economic.

But solar might fit that spot as a peaking unit, if the price can work without subsidies.

[ProtectOurFreedom]

Yes. But you still need to invest 2X in capital equipment: once for the solar plant and once for the backup plant to make power at night and days when the sun doesn’t shine. That’s the dirty secret of solar.