Best of the Above – Energy for Western Colorado

A recent commentary described ideas for “all of the above” energy for Western Colorado. What will constitute our energy future, and can we identify a more appropriate approach based on a “best of the above” strategy? Coal should also be kept on this list with oil and gas extraction and energy production, because it provides almost half Routt and Moffat’s tax base in Northwest Colorado, high-income jobs and supplies clean, reliable 24/7/365 low-cost electricity. Additional ideas included were: geothermal electrical generation, grid-scale battery storage, hydroelectric pumped storage, natural gas electrical generation, carbon dioxide capture, nuclear power electrical generation, solar power and storage and biomass electrical generation. Here is some information which may be helpful as we contemplate how to meet our future electrical needs.

• Geothermal electrical generation has an average of just 12% efficiency (net electricity produced divided by the energy input). This compares to 64% average efficiency of combined-cycle gas turbine (CCGT) generators. Further, the capital cost for geothermal, per unit of electricity produced, is more than three times that of CCGT units.
• Grid-scale battery storage is a non-starter. The average duration of lithium-ion grid-scale batteries is four hours. Xcel Energy has announced a demonstration-scale 10-megawatt, 100-hour duration system using iron-air technology. It will occupy 5 acres of land, with a round-trip production efficiency of only 35-38%. Moreover, battery cells would need to be replaced after just 10 years.
• Pumped storage hydropower essentially acts as a battery, generating power through the movement of water between two reservoirs — one higher, one lower. The $1.5–2 billion proposed project between Hayden and Craig would take at least five to six years to complete and would be capable of producing 600 megawatts of power over eight hours. What happens then?
• Our abundant natural gas reserves should be used to supply new CCGT generators replacing our local coal-fired plants, while reducing carbon dioxide emissions by around 50%. Because carbon dioxide is only .4 of 1% of the atmosphere, reducing its amount by any percentage is costly and will be added to consumer electric bills. Indeed, according to the IPCC (Intergovernmental Panel on Climate Change), if the entire United States met its 2050 net zero goal, the amount of warming averted would be only 0.034 degrees Celsius – a trivial amount which no one could feel.
• Carbon dioxide capture and storage systems do not work, even though the EPA has proposed a rule that requires their adoption. Of the more than 3,000 coal-fired power plants in North America, exactly two of them — one in Saskatchewan and another in Texas — currently use such systems on a commercial scale. Both units capture far less emissions than the EPA 90% requirement, and do so at enormous cost to the consumer.
• Next-generation nuclear plants are a definite possibility for Western Colorado. They could be sited at current coal plant locations, saving the cost of supporting infrastructure. Consider the Natrium reactor under construction near a retired coal plant in Kemmerer, Wyoming. The 345-megawatt unit will provide 24/7/365 electricity to 400,000 homes. A similar unit could be a great replacement for our current coal-fired power plants.
• Renewable energy sources such as wind and solar are intermittent and require backup by “dispatchable” capacity to meet demand and stabilize grid voltage and frequency. System costs escalate with increasing proportion of variable renewables. Combining intermittent power with utility-scale batteries could potentially reduce reliance on natural gas for peaking power, but these can only marginally flatten the supply curve, and only for a few hours. They cannot store solar and wind energy from Monday so that you can use it on Wednesday.

The 19-megawatt biomass generation plant proposed by Xcel Energy for the Hayden power plant would be a step backwards. In addition to low efficiency (around 20%), burning biomass fuels results in the release of various other harmful gases such as carbon monoxide, NOx (nitrogen oxides) and VOCs (volatile organic compounds), which all contribute to air pollution. It would be better for the environment to keep the coal-fired units operating.

So a “best of the above” energy strategy would energetically pursue new natural gas-fired plants and next-generation nuclear power. In the meantime, our political leaders must act to keep our coal-fired plants operating to supply reliable, 24/7/365 dispatchable, low-cost electrical power for all, adding alternatives only when they demonstrate the same capability.