The world faces an existential fight in fighting Cliamte Change. Currently the extra heat added to our atmosphere and oceans is equivalent to over three World War II Nuclear Weapons per second. Yet, at the same time, Â many of our most effective carbon-free sources of electricity, our nuclear plants, are facing shutdown. They face shutdown because they can not recover their fixed costs in markets based on incremental energy costs.
In the debate over nuclear, it is essential to realize that carbon emissions will increase dramatically when Nuclear Units shut down. Nuclear will not be replaced by renewable energy; nuclear will be replaced by units producing more carbon than the average unit currently running. Â
Units on the grid are dispatched in “Merit Order.” The cheapest plant is dispatched first, then the next cheapest plant, and so forth. It makes no sense to run a 5 cent/kwh plant if a 2 cent/kwh plant is available unless reliability or transmission constraints are present.Â
If a 1,000 MW nuclear plant shuts down, Â all available renewable units will already be running as renewables generally dispatch first due to their low costs. The additional units dispatched will be those that were just above the market-clearing price when the nuclear unit was running.
Dispatch price, based mainly on fuel price and heat rate, is a good proxy for carbon emissions. On average, these newly dispatched units will have higher carbon emissions than the units already running. Thus shutting down nuclear units will cause significant increases in Carbon emissions.
Rather than retreat in the war on carbon, we must use everything we have; we must go forward by keeping our existing nuclear units in service and adopting Small Modular Reactors.
Imagine that United Airlines needed a new airplane, their VP of procurement calls an Architect Engineer, and they design the plane and then build it on a Taxiway at Newark, resulting in a cost of several billion dollars per plane. That is the way we built our existing nuclear units. Of course, we would buy the components such as the NSSS System from Westinghouse or GE, but the “Balance of Plant” was pretty much a “one-off” design for each plant, and the cost was measured in billions of dollars which seemed to escalate monthly.
Small Modular Reactors give us the same cost savings available to the Airlines. Whereas United calls Boeing and says (after much haggling), “Send me a 777.” We will now be able to buy standardized factory-built nuclear units at a fraction of the cost of a large, specially designed unit.
Further, the SMR’s offer the high reliability essential to the grid. Several SMR units can be hooked to a common steam header, which feeds multiple steam turbines. In this configuration, any unit or turbine can be taken out of service for maintenance, and the plant continues to run.
The fight to reduce carbon requires using every resource at our disposal, including nuclear. Maybe in a perfect world, we could go to 100% renewables, but we do not live in a perfect world. We can get to 70-80% renewables with our current technology and the technology available in the next few years. But the complexity of the grid requires more than just cheap energy sources.
IN 2003 the National Academy of Engineers gave an Award for the most impressive engineering achievement of the last century. The winner was not the Space Shuttle or the Internet; it was the Electric Grid which has been called the most complex machine in existence. Grid Stability and reliability require so much more than just renewables and batteries. It requires Generator Inertia, VAR Compensation, Complex Relay Schemes, Balancing, Transmission to allow synchronizing current and Frequency Bias Current to flow, Underfrequency load shed, and a host of other items. SMR’s can help provide these needed items allowing us to achieve higher percentages of renewables.
Many will push for Microgrids, which certainly have their place in the larger picture. But with Microgrids, you doom wind as rooftop wind is not exactly prevalent. You lose the ability to locate solar in areas where it will have a high capacity factor. You lose the ability to share (and materially decrease) reserves. You lose the ability to sell renewable energy into price spikes in other areas making renewables more attractive as an investment leading to more renewable penetration.
Let’s not allow intramural fights between different types of Carbon-free energy to impede us in the goal of a Carbon-free grid. Let’s keep our existing nuclear units running, adopt Small Modular Reactors, enable the grid to support high levels of renewable energy, increase renewable portfolio standards, pass carbon taxes, work together and welcome anyone with a solution.