You know the cliché about work that can be 59 minutes of boredom and one minute of white knuckle excitement and danger? In the electric power industry, this happens when a major power plant loses its connection to the grid, instantly and dramatically unbalancing the supply and demand of electricity. Blackouts follow if there isn’t an instant response.
Last week I had a similar exciting moment at a conference of utility commissioners, where I learned that a key grid reliability requirement during these emergencies has not been provided by new natural gas plants.
Assumptions are not always true
Throughout the electricity engineering community, there is an assumption that, when that kind of supply-demand imbalance incident happens, there will be an automatic response within 5-6 seconds from conventional (gas, coal, hydro) generators that stabilizes the power supply. How valid this assumption is matters, because it is used by practically every utility study and commentary aimed at highlighting limits to using renewable energy to replace fossil-fuel power plants. (See here, for example.)
The assumed difference between conventional power plants has figured prominently in current debates about the adoption of renewable energy versus an over-reliance on natural gas and coal.
Surprised looks all around
But what if that assumption turned out to be wrong? In a thinly attended session on a Sunday at the summer meeting of NARUC, (the National Association of Regulatory Utility Commissioners) I attended, a representative from NERC (the North American Electricity Reliability Corporation) committee process made an astounding revelation, that this assumption has indeed been mistaken.
The reality is that a thousand gas-fired power plants built in the U.S. do not operate properly in white knuckle emergencies. In the discussion with regulatory staff, Troy Blalock, reliability expert at South Carolina Electric & Gas, explained how jaws hit the floor as NERC’s investigation into reliability questions found that all three of the gas generator manufacturers (GE, ABB, Siemens) predominant in the U.S. had for years been delivering equipment that fail to provide this “essential reliability service”. As word spread around the 3-day NARUC conference, this news caused the same speechless, open-mouth expression.
Fossils vs. Renewables
This new information has huge implications for debates about power plant retirements and the EPA’s Clean Power Plan. NERC has not been supportive of a transition away from coal and into wind and solar, but at least one of their key concerns has been based on this misunderstanding that gas plants can always respond to these emergencies while wind and solar can’t.
To the point, just weeks before releasing a controversial report assessing the reliability concerns related to the EPA Clean Power Plan, NERC sent a red letter warning to the power industry and held a webinar saying that reliability was threatened by this failure in basically all new gas plants.
This revelation that U.S. grid reliability has been weakened by a thousand new gas-fired power plants negates the findings of several dramatic statements and studies that warn about impacts from increased use of renewables. California energy policy, FERC inquiries, and LBNL lab reports were all misled by the lack of this information that the gas-fired units are not contributing to frequency response during emergencies caused by sudden trips of large conventional generators.
Solar makes changes to improve reliability, and wind can do it too
Even more offensive to renewables advocates than the exaggerated, mistaken reliance on an assumed performance from gas plants, the power industry and media has repeated ad nauseum a story of German solar power equipment needing to change its control settings to make sure it helped, not hurt reliability—when all that time, the same thing was needed at gas-fired power plants.
As it happens, solar can make those changes, and has, a whole lot more quickly than gas plants. In Hawaii earlier this year, the solar industry successfully changed the control settings on 800,000 solar panel inverters through internet connections to make solar in Hawaii support frequency and voltage in similar emergencies.
Recognizing that grids need this service, a variety of wind turbine manufacturers have designs that provide the frequency response that is missing from the gas turbines (see here, here, here, and here, for example).
Perhaps the lack of incentives is the root of the problem
Because there is a lack of incentives for any generator to provide the frequency response we’ve been discussing, there hasn’t been a technology-neutral accounting of this service. It’s a win-win-win to fix this. We can do it in a way that leads to the grid of the future, rather than incorrectly relying on the grid of the past to maintain reliability.
Fixing the gas plants would be cheap
In last week’s session, NERC’s representative said that the cost to correct the mistake in controls at each of the gas-fired power plants is on the scale of the budget for coffee for the operators of these power plants. Despite the problem going unreported for 25 years, NERC suggested that a few memos, and no regulatory interventions, would be adequate to get the gas-fired fleet back up to expected reliability.
No mention was made by this representative of the bigger picture, and the inappropriate accusations over the years that wind and solar, rather than gas plants, are the cause of this problem. It’s time to set the record straight—and get back to our 59 minutes of boredom.
Source: Renew Economy