80-100% Carbon Free - Brian Jensen

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I think there is a straightforward path toward 80% carbon free energy for all energy sectors transportation, electricity and industry. Currently carbon free (or carbon neutral) energy accounts for 21% of the U.S. total energy needs. Why the range of 80 to 100% in the title? Getting to 100% carbon free energy is really hard and expensive, 80% is much more achievable with existing technologies. If we truly need to get to 100% carbon free on a total energy basis to stave off the worst of climate change, then we need to attack the remaining 20% with a mix of carbon capture and advanced storage and other technologies. I haven't listed a time frame for all of this, it is possible by 2050, but this would take a huge effort, and the U.S. and the world would have to be fully committed and significantly ramp up their current zero carbon efforts to make this happed by 2050. The process of going from 21% to 80% involves adding more and more renewables and other clean sources of energy while managing the load to utilize all the clean energy.

Figure below is the California electricity "Duck Curve".

The keys to utilizing more renewables (hence keeping renewables attractive for continued investment and decarbonizing energy) include:

Shift as many loads as possible to the peak sun time of the day while lowering loads when renewable energy production is low.
Install more wind to cover peak load times (in California).
Switch other renewable power generation (hydro, geothermal, biomass) to variable where it makes sense.

Items below are some concepts to increase the carbon free energy percentage to 80%:

Install workplace electric vehicle charging to incentivize EV driving and charging at peak sun.
Have a massive education campaign on time of use (TOU) electricity metering. Households and businesses will manage their loads around lowest cost energy (peak renewable generation).
Electrify housing and businesses with HVAC heat pumps, heat pump water heating, and all electric appliances.
Install battery energy storage where it makes sense. Solving the duck curve problem with battery storage alone would be too expensive. Connect all home and business on-site energy storage to the grid and pay customers to use half of their battery pack during critical needs (this reduces natural gas peaker plant use).
Install load controls (smart or time based) on large electric loads (EV charging, hot water heating, washing machines, etc.) so they operate at peak sun hours or after peak evening load.
Globally about 75 million tons of hydrogen is produced annually (for industrial, petrochemical, fertilizer uses), 99.9% of this hydrogen is produced from fossil fuels. All of this current hydrogen production can be switched to using renewable power using electrolyzers. Hydrogen production can be made during the day at peak sun times. The key is to use the lowest cost energy available (peak renewables production) and not to produce hydrogen from stored power (don't use energy storage to create hydrogen, the economics are a lot worse). Another key element to enable this is R&D investment is variable production hydrogen to reduce the cost of the electrolyzers. When all of the hydrogen is produced for industry and transport is carbon free, then we can have the conversation about hydrogen for power generation. Hydrogen can be converted to synthetic natural gas for longer term storage to operate power plants for extreme weather events or long periods of low renewables production (storing and transporting synthetic natural gas is easier than using hydrogen directly, no change in infrastructure needed).
Build more transmission lines to move renewable power where it is needed.
Schedule very large power source demands (state water pumping, desalination, etc.) to run 100% at peak sun hours and ramp down at peak demand.
Greening transportation autos and small trucks are straight forward, lithium batteries work well for these with charging at the workplace and home off-peak. Trucks, ships, locomotives and aircraft on the other hand work best with liquid fuels, Batteries are very expensive and heavy for these applications, and hydrogen as a transportation fuel has its challenges with its density and infrastructure issues (there may be a case for hydrogen in transportation in large off-grid operations (mines, etc.) and small to mid size islands (islands too far for a connection to a larger electrical grid). There are also challenges with bio fuels (land use, competing with food crops, scaleability, etc.). I think synthetic fuels are the way to go for the heavy transport. These fuels can be made with renewably produced hydrogen and carbon capture (from power plants near term and from the air long term).
Continue greening industry energy use by switching as much energy use as possible to electric, then use synthetic natural gas (made from renewables) for high temperature needs.
Carbon capture is very energy intensive, plan on operating these plants on variable power, with plants operating at 100% at peak renewable generation times.

There are many more solutions to reduce carbon, we need to be creative about it. Most of the options listed above require investment, policy changes and determination to make happen. It needs to be a priority.

Some additional links:

California current carbon free electricity percentage

Google's 2030 plan

Gridlab and Berkeley 90% carbon free electricity by 2035 plan

IEA World Energy Outlook report

REN21 report

Center for Climate and Energy Solutions

National Geographic carbon free blueprint

National Potential for Load Flexibility

Wood Mackenzie 50% renewables by 2030

Wood Mackenzie 100% renewables

Hydrogen production