Blackouts Present Opportunities to Implement Reliability Solutions

Texas temperatures have normalized, and power has been restored, but the question remains how can future blackouts be prevented? Additionally, what can the rest of the country learn from the blackouts in both Texas and California?

There are several lessons we can learn from these blackouts, which happened just seven months apart. As a member of the Path to 100% community of experts and through my decades of work for Wärtsilä, I believe now is the time to find answers together to help states decarbonize in a practical, reliable and affordable way.

In August of 2020, Californians suffered largely because the state does not have enough firm capacity within its borders, forcing them to rely heavily on the western interconnect for their power. On the opposite side, and where I want to focus, the Electric Reliability Council of Texas (ERCOT) stands alone — and when their lack of winter preparedness caught up with a grid — engineered only for hot summers and mild winters — there was no one to step in and help. Very simply, you could say that California relies too much on their neighbors for firm capacity, and Texas perhaps too much on themselves to handle any situation, including extreme weather events.

What we have learned from both of these incidents is that there must be adequate, dispatchable, carbon-free power as we see more extreme weather events, like the arctic weather that crippled most of Texas in February.

What went wrong in Texas?

The recent arctic cold wave caused widespread blackouts in Texas because many power plants were not designed for extreme ambient temperatures causing them to become inoperable during the below-freezing temperatures. Although it may be expensive, winterizing gas supply and power plants are required to avoid a similar blackout scenario. The gas system was not able to maintain adequate flow and pressure, meaning utilities were caught off guard when both gas heating and power generation fuel flows peaked simultaneously.

Furthermore, Texas does not have firm rules on power plant engineering for ambient temp ranges. Recommendations from ERCOT were published after the 2011 blackouts, but they are not mandatory like they are in the eastern part of the country. For example, a new large 1,000 MW combined cycle gas plant just north of Houston was designed for a minimum of 15°F, but when temperatures went below 10°F, the plant could not operate. More than 20 GW of power plants had similar issues.

On the open electricity markets, plant investors struggle to see an economic reason for winterizing for extreme conditions that may never happen. Indeed, it is going to be more expensive to engineer power plants to expand the temperature range down from 15℉ to 0℉, but again the critical need for power during these conditions would make the investment prudent.

Wärtsilä has almost a gigawatt of gas power plants in Texas, which are built according to Finnish standards and include an insulated building that covers and protects all equipment — even in sub-zero temperatures. These flexible power plants remained operational during the crisis, which offered some reliability for Texas. Wärtsilä power plants reach 25% of full output in mere 25 seconds after start command and reach full plant output in five minutes, so they can offer fast cure from stand-still in situations when power is needed instantly. They offer the lowest heat rate of any simple-cycle technology in the power industry and constant performance over a wide range of ambient conditions, including in 100+ Fahrenheit heat waves. One important feature that helped Wärtsilä plants produce power in Texas through the crisis is the low 75 Psi gas pressure required to produce full output — gas turbines typically need 300 Psi or more to stay on-line.

Regulators and system planners analyze energy use based on one event in ten years, which determines the need for generation capacity and the required reserve margin. The current planning process does not account for extreme weather conditions that happen once in a hundred years.

Moreover, to handle fuel-supply constraints, dual-fuel generation could offer an efficient and flexible solution. Liquid fuels can be stored in large quantities at power plant sites for occasions when gas is not available or pressure is too low. In the future, liquid backup fuels can be carbon neutral methanol or ammonia, offering firm power with long-term carbon-free at-site energy storage. Additionally, excess electricity from periods of oversupply of solar and wind energy can be used to produce renewable fuels locally.

If everything had worked in the cold, ERCOT could have managed the load during the cold wave without blackouts or with minor and controlled rolling blackouts. In comparison, this is quite different from what happened in California last summer. The Golden State was simply lacking an estimated 5 GW of capacity during the worst moments of the August heatwave.

The benefits of “common sense” regulation

Texas is too “unregulated” regarding the technical requirements to handle ambient temperatures on the power and gas systems. Instead of tearing everything down due to a lack of technical engineering requirements, require winterization of the Texas power system through common-sense policy.

One area where the unregulated ERCOT market remains a bit risky is capacity adequacy since there is no regulation on how much firm capacity must be maintained to cover the peak loads. ERCOT has done well in this area despite the closures of several large carbon-intensive coal plants. However, establishing a firm capacity target will ensure the grid is as prepared as possible for the next extreme weather event.

Integrating renewable energy to provide reliability

Renewable energy was not the main cause for the widespread blackouts in either state, but they are part of the solution. Renewable fuels such as hydrogen or carbon-neutral synthetic methane produced using curtailed electricity from periods of high oversupply from solar and wind — can be used to overcome the long-term storage challenge and produce long-term, dispatchable, or firm capacity.

Adding flexible gas capacity — capable of converting renewable fuels in the future — along with battery storage will help safeguard system reliability under all weather conditions. Old, inflexible power plants need to gradually retire because they do not offer the flexibility necessary to balance the variability of wind and solar power.