Houston — Total capacity in Texas' voluntary Renewable Energy Credit program, including facilities outside the Electric Reliability Council of Texas footprint, increased by about 2.6 GW, or almost 10%, between 2017 and 2018, but industry observers differ over whether such growth may continue.
Some have blamed federally subsidized renewable energy's massive growth in Texas for low power prices, discouraging investment in dispatchable thermal generation, causing ERCOT's record-low planning reserve margins of 8.6% this summer, when ERCOT expects to declare Energy Emergency Alerts.
A renewable energy credit is a stock-like certificate corresponding to an actual megawatt-hour of renewable energy. Renewable power generators can earn and sell the RECs to retailers on the open market. Texas retail electricity providers must acquire and retire RECs based on their load-ratio share of the annual renewable portfolio standard mandate.
DIFFERENT RATES OF GROWTH
ERCOT, REC program administrator, filed the report Wednesday at the Public Utility Commission of Texas (Project No. 27706), showing 28.9 GW of renewable power capacity, up from 26.3 GW in 2017. Wind provided 1.9 GW of the increase, a growth rate of almost 8%, but solar capacity grew at a faster rate, adding about 660 MW, or 52%. Other renewable energy types -- biomass, hydro, landfill gas -- were unchanged, totaling about 583 MW.
Since 2014, solar power in the REC program has grown at a compound annual growth rate of 71.4%, compared with wind's 13.8%.
Cyrus Reed, the Sierra Club's Lone Star Chapter interim director, said his group foresees renewable capacity growth of about 10% in Texas "for many years to come," as corporations and municipal utilities approve long-term power purchase agreements for wind and solar power, and participation in ERCOT's generation interconnection process "continues to be strong."
Another factor favoring solar is the PUC's decision to change the loss-of-load probability parameter of ERCOT's Operating Reserve Demand curve price adder, Reed said, which should cause the systemwide adder to be triggered more frequently at higher levels.
This decision "is beneficial to solar power since it tends to produce power at peak so we think that in particular solar power will be seen as a good investment," Reed said Wednesday.
A 30% federal investment tax credit for solar generation projects in which construction starts this year falls to 26% in 2020, 22% in 2021 and 10% thereafter.
Travis Whalen, a power analyst at S&P Global Platts Analytics, expressed confidence in solar growth, despite the winding down of tax credits, "in large part because of the improving economics of the technology, which has improved dramatically in the period ... and is expected to continue improving in the medium term."
"Our expectation is for solar to double within the next two years, and installations continue at a strong pace throughout our long-term forecast," Whalen said, which ends in 2040.
However, Whalen said the wind growth rate, in particular, "is expected to flatten substantially essentially starting next year with the expiry of the production tax credit."
The federal production tax credit is equal to $23/MWh for wind power for 10 years after the facility goes online, and construction must have started before 2020.
Michele Gregg, Texas Competitive Power Advocates executive director, said the PTC "creates an incentive for negative pricing."
"If prices continue to be suppressed, particularly as our demand increases, then dispatchable generation will continue to see price signals to retire generation rather than to invest, exacerbating the resource adequacy concerns we have been seeing," Gregg said Wednesday.
BILL PENDING IN TEXAS HOUSE
But the value of those PTCs may diminish significantly faster than 10 years, if a bill approved by the Texas Senate on April 24 becomes law. Senate Bill 2232 requires the PUC to study the market effects of federal renewable energy subsidies and recommend ways to counteract them. The bill is currently pending in the House State Affairs Committee. The regular legislative session, which occurs once every two years, ends May 27.
Asked how such a law might affect renewable growth in Texas, Whalen said it is "a difficult question to answer with any specificity, since it would obviously depend on the nature and scale of any countermeasures."
"You could see more economic curtailment if they actively counter existing production tax credits, but any such move seems like it would face strong legal challenges," Whalen said. "Countering solar subsidies would certainly slow installations, but it shouldn't reverse the course for solar generally, given the rate of cost improvements and the benefits solar provides in meeting summer peak demand."
Reed said, "[We] don't anticipate any resulting recommendations would have major impacts on renewable development because the fundamentals of low or zero marginal costs of wind and solar are so good, in addition to the availability of private land."