What Will It Take to Electrify the U.S. Grid?
Michael Molitch-Hou posted on August 29, 2019 |
Engineering.com speaks to John Mitchell about electrifying U.S. infrastructure.

In a previous article on the Green New Deal, we spoke with engineering entrepreneur Saul Griffith about what steps the U.S. would need to take to do its fair share in preventing total climate collapse. Griffith’s immediate first response was to “electrify everything.”

To gain an understanding of what it would mean to “electrify everything” in the U.S., we spoke to John Mitchell, a conservation engineer who draws up proposals for The Climate Mobilization, who actually details such plans. While Mitchell has laid out numerous municipal plans for achieving large-scale electrification, he is in the process of detailing how the United States can do so on rapid scale that would fulfill the goals of the Green New Deal.

Making the National Power Grid Renewable

Currently, the national power grid is predominantly (64 percent) running on the burning of fossil fuels (35 percent gas, 27 percent coal). This glorified version of steam power has caused the atmospheric concentration of carbon dioxide to reach levels last seen3 million years ago. There is an overwhelming consensus that global society, wealthy countries in particular, needs to decarbonize. How we accomplish this is still being debated since the effects of the climate crisis are being felt.

One of the most popular strategies proposed by politicians, businesses and environmentalists alike is to shift society’s sources of energy from fossil fuels to so-called renewable energy, such as wind and solar. There are numerous issues with accomplishing such a transition and doing so in a timeline that might preserve Earth’s ecosystems and inhabitants.

Among those issues is distributing electricity in such a way that balances the advantages of those renewable sources. Collecting, storing and transmitting electricity for solar will depend heavily on where and when the sun is shining. The same is true for wind, as it relates to where and when the wind is blowing.

According to Mitchell, this means improving the existing electrical grid with “at least three” high voltage direct current lines traveling from east to west, along with lines running north to south. He believes that the lines should be buried underground to improve the grid’s resilience during the increasingly dangerous climate emergencies set to come. To overcome issues associated with land use and easement, he argues that this could best be achieved by burying the lines along the U.S.’s existing federal highways.

This strategic layout will be necessary for coordinating power supply with the aforementioned natural forces. “That’s going to be required so that we can have large solar farms in the Southwestern United States and to incorporate the explosion of Midwest wind farms, as well,” Mitchell explained.“When the sun is still up in the Western states, we’ll be able to pump large volumes of electricity to the high-density population centers on the Eastern Seaboard who are just coming home and cooking dinner at 7 p.m. while the Western states are still getting a good amount of sunshine. These kinds of things will reduce the storage capacity required.”

Manufacturing Renewable Energy

Currently, the overwhelming majority of solar equipment imports to the U.S. come from Asia. If we want to reduce the emissions related to shipping those goods, manufacturing of this equipment will have to be shifted back home. Mitchell is currently working on a national renewable energy proposal that seeks to achieve just that.

“The national plan calls for a regional manufacturing center to be developed in nine distinct locations throughout the country,” he said. “This is for the distribution of materials and the dissemination of infrastructure in the local region based on the population and the type of resource need that’s going to be there at that location. For example, large solar manufacturing in the Southwest and wind turbines in the Midwest.”

His currently plan is modeled after the PV Pioneers Program, implemented by the publicly owned Sacramento Municipal Utility District (SMUD) in the 1990s. After the community voted to close the Rancho Seco nuclear power plant, the city needed to generate alternative energy. Given the price of photovoltaics (PVs) 30 years ago, obtaining low-cost solar was a daunting project. The solution, however, wasn’t a technical one but a bureaucratic one.

In 1993, the utility began selling standardized 2kW PV panel packages for a minor $4.00 per month premium to residents interested in solar energy. This was augmented by standard permit applications for local governments, which eases the approval process and lowers bureaucratic costs.

“[SMUD was] able to have least cost bids for solar installer contractors who would receive large amounts of contracts with only minimal markups for each of their installations,” Mitchell said. “They even packaged, distributed, stored, staged and delivered the system for building the arrays to streamline the process.”

Since then, the cost of solar panels has gone down and the power capacity has gone up. According to one estimate, “In 2001, the total cost of a 2 kW solar array purchased under the program was $9,000 ($4.50 per watt) with the customer's share at just $6,000. That installed cost was nearly 10 years ahead of its time.”

Mitchell believes that the SMUD model could be blown up to a national scale, with the addition of subsidized labor training for the hundreds of thousands of installers needed for the project.

“In doing so, we could drop the cost of solar from its current $3 dollars per watt down to under $1.5 per watt for rooftop solar,” he said.

With a federal financing authority able to create a loan program, it would be possible for the cost of solar to be accounted for with minor monthly bills to the consumer. This would mean no money down and no major change to their electric bill for the first seven to ten years. This would be further offset by the money generated from the sale of electricity back to the grid.

According to the National Renewable Energy Laboratory, rooftop solar could account for about 40 percent of the country’s electrical power without the need to buy and use new lands. Mitchell doesn’t currently see there being a need for deploying capital-intensive and controversial nuclear energy, instead suggesting that renewables can account for the entirety of the energy grid.

That includes, in addition to wind farms in the Midwest, offshore wind installed off of the East Coast. These turbines can provide a significant portion of evening power, especially during the winter months, to the Atlantic seaboard.

Power Storage for Alternative Energy

Because the wind and sun can’t be turned on and off at the push of a button, energy storage systems will be essential to capturing electricity generated by solar arrays and wind turbines. The most obvious method for storing energy is the use of lithium ion batteries, due to their increasing ubiquity.

The global lithium ion battery manufacturing capacity is estimated to grow from 220 gigawatt-hours in 2018 to 1.1 terawatt-hours in 2028, according to Benchmark Mineral Intelligence. This will be further improved by general advancements in the technology, as well as new relationships between building and vehicle infrastructure.

Mitchell, along with engineer Saul Griffith and architect Doug Farr, believes that we are headed toward a future in which cars and houses will work almost symbiotically, with vehicles sending electricity to buildings when they are not in use. If all of these structures and automobiles are thought of as one whole, this energy can be even more efficiently distributed.

Tesla is attempting such a feat in South Australia. There, the company is working with the South Australian Government to install 5 kW solar arrays and 13.5 kWh Tesla Powerwall 2 battery systems across 50,000 homes. The project team estimates that the “Virtual Power Plant” will be possible to create at least 650 MWh of distributed energy storage capacity throughout the state. Whether or not they can pull it off is another story given Tesla CEO’s other recent issues, but the concept itself is definitely not impossible.

Problems with Material Sourcing

The use of lithium-ion batteries does have potentially larger obstacles to overcome, such as the geological constraints of Earth itself. In a chapter on “Renewable Energy Resource Assessment,” the authors of Achieving the Paris Climate Agreement Goals estimate that there will not be enough lithium or cobalt to meet the production required for renewable technology demand.

The authors wrote: “The cumulative demand for cobalt from renewable energy and transport exceeds the current reserves in all scenarios, and for lithium, the cumulative demand is exceeded in all scenarios, except the ‘potential recycling scenario.’”

Image courtesy of Achieving the Paris Climate Agreement Goals.
Image courtesy of Achieving the Paris Climate Agreement Goals.

Mitchell and the chapter’s authors pointed to alternatives to lithium-ion batteries, such as lithium-sulfur, to replace the rare and problematic metal cobalt. The report, however, notes that “a shift to Li–S will increase the demand for lithium because these batteries have a higher amount of lithium.”

Instead, the authors suggest that recycling metals will be a more viable method for obtaining rare materials. There are several problems with this solution, however. Currently, the recycling infrastructure is not sufficiently developed. The recycling processes for some materials can be environmentally and socially hazardous in themselves. 

It’s also worth noting that all of these materials are or will be increasingly involved in global conflict. Cobalt is a prime example. It is currently one of the rare metals fueling military conflict in the Great Lakes region of Africa and is associated with human rights violations, child labor and pollution.

In the Andes, lithium mining water tables are being destroyed, lakes drained and ecosystems wrecked while indigenous farmers are driven from their land. Both of these cases underscore the unequal relationship between the Global North and South, with wealthier countries exploiting poorer ones for their resources in order to fuel consumptive lifestyles.

Mitchell sees overcoming this disparity as being key to ensuring an ecologically sustainable future.

“If we allow half our population to suffer and die, I don’t think any of us will survive,” he said. “The treatment of the Global South or more impoverished nations in how we utilize these resources is going to be key to whether or not we survive in the long term. It is my hope that we will recognize the collective threat and align together to ensure our survival.”

In addition to the human impact, the destruction of wildlife, habitats and ecosystems that occurs as a result of mining and other extractive procedures. In the effort to fight climate change, it should not be ignored that the planet is simultaneously facing an extinction and biodiversity crisis.

The UN Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services believes that the unprecedented loss of animal, insect and plant life is as great as a threat to life on this planet as the climate crisis. Some species are going extinct at rates of tens to hundreds of times more quickly than in the last 10 million years.

Alternatives to Storing Alternative Energy

Faced with the obstacles from the chemical energy storage methods described above, many look for other means of storing power. Mitchell highlighted two interesting possibilities: pumped hydroelectric energy storage (PHES) and compressed air energy storage (CAES). 

In PHES, energy is stored in the form of water and gravity. When electricity generation is greater than the demand, the power is used to pump water up to a higher elevation reservoir. Then, when demand is greater than the amount being generated, water is released downhill, pushed by gravity to spin turbines and create more electricity.

So far, PHES is the largest form of grid storage available. The U.S. Department of Energy lists PHES as representative of 95 percent of all active tracked storage globally at over 184 GW of capacity installed. The U.S. has 25 PHES sites.

PHES facilities are net consumers of energy due to the losses occurred in pumping water, with round-trip energy efficiency for these systems ranging between 70 and 80 percent. Obviously, the major drawback from such a system is that it requires a great deal of water and storing it at a sufficient height. This usually means mountainous areas, raising possible ecological and social issues, but it may also be deployed in disused mines and other brownfield locations (previously developed land that is not in use).

Mitchell pointed out that there are emergent storage systems that serve as alternatives. This includes a method that uses cranes and blocks of concrete, developed by a Swiss company called Energy Vault, as well as a technique involving trains, hills and concrete, pioneered by Advanced Rail Energy Storage.

The environmental engineer, however, is an advocate of CAES. In the case of CAES, surplus energy is stored in the form of compressed air and released when demand is high to power a gas turbine. Existing systems rely on underground salt caverns to store the air, leading to efficiency of about 70 percent and the need for natural gas to fire up the turbine due to temperature drops from the depressurization process.

To overcome this issue, Mitchell proposes the use of what he refers to as a “trigenerational above ground system.” While the heat captured from pressurizing the gas can be used to heat buildings, industrial applications or for cooking and heating water, the ultracold temperatures produced from the depressurization process can be used to cool buildings, chill water for industrial activities or for single pass air cooling of solar farms and rooftop solar—to create an additional 7 percent generational efficiency to solar arrays.

The Social Buy-In

Regardless of the exact methods used to generate and store power, Mitchell believes that a massive federal program will be necessary to deploy them. Using federal funds for large infrastructure projects is not unheard of in the U.S. In fact, it’s something the country was once known for in the 20th Century.

“There are federal authorities for electrical power distribution at the local level: the Bonneville Power Administration and the Tennessee Valley Authority,” he said. “Those are both associated with large-scale national projects, developing massive hydroelectric power in the Pacific Northwest the other for a rural electrification program in the 1930s. Those are the kinds of programs we’re talking about.”

The planning and technologies are all ready to go, but there are social and political obstacles preventing their implementation, according to Mitchell. Because there are so many aspects of the Western lifestyle that are in opposition to the survival of the planet, he believes that the U.S. government will need at least a 70 percent buy-in from society as a whole to begin executing the transformation required to survive. 

“You couldn’t buy a private vehicle during World War II. They just didn’t make them because they were all making material for the war,” Mitchell said. “In our current situation, internal combustion-driven cars may need to be off the table. Those are kinds of measures that are going to be required when you have a national climate emergency and mobilization. The primary reason why you would need to have at least a 70 percent national buy-in to the climate emergency as a national emergency is the inertia of trying to incorporate consumption restriction for certain goods and services that have a high carbon footprint.”

Once this buy-in occurs and national momentum does shift in the right direction, the sustainability engineer believes a social transformation will necessarily follow. This will involve broad social welfare and education programs that will be needed to survive the likely market upsets that will result from jolts to the fossil fuel economy.

In Mitchell’s view, implementing the necessary strategies to fight ecological collapse will necessitate leadership from the executive branch downward, including the overwhelming majority of congress. However, to make that happen, collective action will be required to fight entrenched moneyed interests involved in the political process. He highlighted a2016 Princeton study that found: “The central point that emerges from our research is that economic elites and organized groups representing business interests have substantial independent impacts on U.S. government policy, while mass-based interest groups and average citizens have little or no independent influence.”

In order for that mass action to occur, Mitchell argued that severe climate events will likely have to wake people up to the emergency at hand. 

“My understanding is that would occur when we have a significant collapse of the arctic sea ice and then the large changes to our weather patterns: heat waves, droughts, hurricane events in the Northern hemisphere,” he said. “Even so, it would still probably require something like 600,000 people in D.C. blocking the roads for six months before we actually got that level of national emergency, but we’ll see.”

As the conversation continued, we learned that this was only the tip of the melting iceberg for both Mitchell’s proposals on changing the national energy infrastructure and his thoughts on sociopolitical factors. We went on to discuss electrifying transportation, replacing the agricultural system and the reality of climate predicament we’re facing. These included autonomous vehicle fleets; no-till, organic farming; strategies for direct air capture of carbon dioxide; and the fact that we may already be locked in for 3 to 4°C of warming this century. These topics and more will be covered in our follow-up with Mitchell.

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