Clean energy must be done better

Speakout

Robert McTaggart, assistant department head of Physics at SDSU
Posted 7/1/21

Building more charging stations will not help electric vehicles unless we make more electricity. To do this sustainably, we must address the long-term life cycle issues associated with making clean energy.

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Clean energy must be done better

Speakout

Posted

Building more charging stations will not help electric vehicles unless we make more electricity.  To do this sustainably, we must address the long-term life cycle issues associated with making clean energy.

One such issue is our preference for a once-through cycle that is cheap initially.  Although much of a solar cell can be recycled, it is not, and the silicon-containing material presents challenges.  For wind, we are just starting to downcycle wind turbine blades and explore biodegradable materials.  Nevertheless, little downcycling or recycling of renewable waste (or “clean waste”) occurs today.

For nuclear, we plan to throw away 90% of the energy that remains in nuclear waste.  Moreover, none of the critical elements that would benefit renewables and energy storage are being recovered from spent nuclear fuel.

Building better nuclear, renewables, and efficiency measures that are easier to recycle will help.  We also need to power our recycling with clean energy to facilitate less mining, less reliance on others for our critical elements, less waste to bury, and fewer carbon emissions. 

The carbon emitted to solve the intermittency of renewables is problematic.  Texas has the most wind capacity.  California has the most solar capacity.  Yet both used fossil fuels to deliver enough air conditioning during our summer heat waves.

Using the same approach to recharge electric cars will emit more carbon.  We need energy storage, fossil fuels with carbon capture, and nuclear power to complement renewables at the utility scale.  Of these, nuclear power is the most ready.

Recently, a sodium-cooled nuclear reactor supported by Bill Gates and Warren Buffett has been discussed for Wyoming.  It is designed to deliver flexible power to support renewables.  By not using water for cooling, safety is enhanced, it is resilient during a drought, and it can deliver the requisite carbon-free process heat to recycle wind, solar, and battery technologies.  If similar reactors consume our existing nuclear waste, all the better.

A growing common interest for nuclear and renewables is making hydrogen.  

Hydrogen is an alternative to natural gas and batteries for just-in-time energy that emits water instead of carbon during power generation.  We can reduce intermittency issues by using excess grid energy to generate hydrogen.  Furthermore, biomass is a potential feedstock for hydrogen.

More renewable energy is terrific if we match supply with demand, become more sustainable and carbon-free, and build clean energy technologies in the United States.  Avoiding nuclear energy, emitting backup carbon, and throwing away imported renewables and batteries do not help.  Yet that is exactly what we are doing.