US agency’s plan to decarbonise power could walk back requirement for some plants to co-fire hydrogen from 2032: report
Industry and environmental groups have both criticised the draft regulation’s push for H2 to decarbonise intermediate-load power plants
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However, “intermediate-load” power plants with a capacity factor between 20% and 50% are mandated to go down the hydrogen pathway, as this is the only technology named as the “best system” of emissions reduction from 2032.
The EPA is set to publish the final rules next week, with expectations that fierce criticism from both industry associations and environmental groups could prompt other pathways to be included for intermediate-load power stations at least.
Trade association Edison Electric Institute (EEI), which represents investor-owned utilities in the US, argued in a letter to the EPA: “Neither CCS nor hydrogen blending are adequately demonstrated today as they are not deployable, available, or affordable across the entirety of the industry, and the attendant supporting infrastructure will take more time than EPA predicts to deploy.”
It added that while constituent parts of hydrogen blending or CCS have been demonstrated, the agency had not proven that that either system functions as a whole — ie, the operation of a power plant using these technologies, rather than an individual turbine — and could therefore not today set either as the “best system of emissions reduction” for future emissions reduction.
“Furthermore, despite the rule’s nominal ‘best system’ designation of 30% hydrogen co-firing starting in 2032 for intermediate-load units, the agency provides what amounts to a nominal emission rate that the vast majority of such operators could easily attain even without the use of hydrogen by simply constructing and operating natural gas combined cycle (“NGCC”) units,” the environmental groups added.
The EPA had excluded combined-cycle gas turbines as an option for intermediate-load power plants owing to high cost — 250% that of simple-cycle units — while the scale of emissions reduction was “unclear”, arguing that these power stations are not used enough for efficiency savings to factor in.
However, the environmental groups responded in their letter that these assumptions were wrong on all counts.
“First, EPA’s unsupported claim that the capital costs of a combined cycle units are 250 percent that of a comparable simple cycle turbine is dramatically off the mark,” they began, citing three reports which found a lower per-kilowatt cost for combined-cycle units than new simple-cycle turbines in some or all analysed scenarios, and one which showed the cost difference was less than 15%.
The environmental groups added that, based on data from the existing fleet of gas turbines operated for hours equivalent to an intermediate-load power plant, combined cycle units emissions rates were “approximately 20% lower” than those of simple-cycle turbines.
“Although hours of operation are not a perfect proxy for intermediate-load operation, these figures leave little doubt that, even for an aging fleet, combined-cycle generation provides significantly lower emissions for intermediate-load operation than simple cycle generation,” they argued.
The letter also dismissed the EPA’s claim that the stop-start operation of these power plants would negate any efficiency savings: “Furthermore, frequent starting and stopping is not characteristic of intermediate-load units, which typically run from mid-morning until evening and then ramp down or turn off at night.”
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