Cities push for 100 percent renewable electricity—whether the goal can be met still debatable
Energize Weekly, August 30, 2017
The push to reach 100 percent renewable electricity generation, led by U.S. cities, is sweeping the nation, but what that means and whether it can be done is still a subject of intense debate.
Forty cities have set some sort of 100 percent renewable goal. In 2015, Hawaii adopted a renewable power target of 100 percent by 2045. This fall, California is considering legislation to impose a 100 percent requirement by 2045.
There have been studies and some controversy on what it would take to power the entire nation with renewable energy.
“How do you operationalize these goals?” asked Elizabeth Doris, who manages the State, Local, and Tribal Program at the National Renewable Energy Laboratory (NREL) in Golden, Colo. “What is the feasibility? These are open discussions. Everything is changing very quickly.”
The 100 percent goal gained added momentum after President Donald Trump announced in June that he was withdrawing the U.S. from the Paris climate accord. Within weeks, the U.S. Conference of Mayors had approved a resolution supporting a 100 percent renewables target.
With the Trump administration abdicating leadership on climate policy—last week, it disbanded a federal climate advisory panel—cities, states and private companies are stepping into the breach, said Kassie Rohrbach, associate director of the Sierra Club’s Ready for 100 campaign. The campaign works with cities and civic groups on developing 100 percent renewable programs.
At the same time, the initiatives very much local. “We are seeing it all over the country, but it isn’t related just to one national trend,” Doris said. “It is happening in cities that have longstanding values.” Portland, Ore., for example, has long-established programs on energy efficiency, and Atlanta has a tradition of “self-sufficiency,” she said.
The “what and the when” of 100 percent renewable generation vary. The target times range from 2030 to 2050. In most cases, the focus is on electricity, either municipal consumption or citywide, and it doesn’t include other energy-consuming sectors such as transportation. San Diego has a 100 percent target, but natural gas for homes and hot-water heating aren’t included.
Then there is the question of how a city can claim it is running on 100 percent renewable power. “If you have a big municipal utility and you have a storage facility, like a big pump storage, maybe you could do it,” said Doris.
Burlington, Vt., which has a municipal utility and gets the bulk of its electricity from hydropower, became the first city to reach the goal by adding a biomass plant and wind turbines. Still, there are times Burlington Electric Department must buy power off the regional grid, which may not be renewable, for the city of 42,000.
It was a trickier exercise for Aspen, Colo., to reach its 100 percent goal. It took 10 years to get to the milestone, which the city reached in 2015. “We bought into a wind farm in Kimball, Neb., in the early 2000s and explored different projects,” said David Hornbacher, the city’s director of utilities and environmental initiatives. “The last 20 percent was difficult.”
The city met the goal with purchase power agreements (PPA). It signed a PPA with the Tri-County Water Conservancy District for the electricity from a new hydro project in Ridgway Colo., about 88 miles from Aspen as the crow flies. It also signed a second PPA with the Municipal Energy Agency of Nebraska for power from wind farms in Nebraska and South Dakota, the closest of which is about 200 miles away. The final 1 percent comes from an agreement with an Iowa landfill biogas plant some 900 miles away.
The city’s 72 million kilowatt-hours a year of electricity consumption is now met 46 percent by hydro, 53 percent by wind and 1 percent by biogas. Aspen pays transmission fees to put the renewable power on the grid, but the further away from the city, the less certain where those electrons go.
Still, Hornbacher said that Aspen’s financial support for the Ridgway hydro project and the Nebraska wind farm were key in their getting built.
The city is also clear that it is just the municipal utility that has reached the 100 percent target for the electric department, which serves only half the city of 6,800, the rest gets their electricity from Holy Cross Energy, an electric cooperative, which produces 35 percent of its power from renewable sources.
“We still have a goal to continue to push forward to migrate the rest of the community to 100 percent solar, which will require cooperation with Holy Cross,” Hornbacher said.
“We hope that what we’ve done is provide an inspiration and encourage other cities to find their own path,” Hornbacher said. “The path is going to be different for different communities.”
Burlington, Aspen and Greensburg, Kan., are the only three cities to reach the 100 percent renewable target—all three have municipal utilities.
Cities that don’t have municipal utilities but are served by regional wholesale power markets, which are operated by regional transmission organizations (RTOs), while not in a position to claim every electron used in their municipality is renewable, can say they are making their grid greener and creating a demand for more renewable generation. “It is a lot harder to make the argument when you are not in an RTO,” Doris said.
The same year Aspen met its goal, San Diego, Calif., set its own 100 percent target for the year 2035. The move came as part of the city’s Climate Action Plan, which aims to cut San Diego’s carbon emissions, half by 2035.
“There are only so many ways to reduce emissions,” said Cody Hooven, San Diego’s chief sustainability officer. “If you look at something like transportation, there are a lot more negotiations with other jurisdictions. So, we focused on energy.”
The city, however, doesn’t have a municipal utility and is served by San Diego Gas & Electric (SDG&E), an investor-owned utility. “We are exploring several pathways,” Hooven said.
One option could be “community choice” energy. California gives towns and cities the ability to aggregate their electricity demand and buy power on the wholesale market. Marin and Sonoma counties and San Francisco are already using community aggregation.
A report on other options will be sent to the city council earlier next year, Hooven said. “Any pathway we take, we want to look at local generation . . . at least in the region,” she said.
San Diego’s plan has its skeptics and opponents. SDG&E received regulatory approval to spend money on a public relations campaign on community aggregation. “They have formed an independent marketing division to engage and lobby along their perspectives,” Hooven said.
Other utilities are responding in different ways to the push for all-renewable electricity. In April, Portland, Ore., adopted a 100 percent target for 2050. In May, Portland General Electric, the investor-owned utility that services the city, suspended plans for two new natural gas-fired plants, saying it did so after listening to customers, regulators and stakeholders.
Salt Lake City, Utah, set a 100 percent goal for 2032 in July 2016. The move came at the same time the city was renegotiating its franchise agreement with Rocky Mountain Power, a subsidiary of investor-owned PacifiCorp, to serve as the community’s electricity provider.
In August 2016, the city and the utility signed a Clean Energy Cooperation Statement that lays out how the two will work to develop clean energy resources. In September, the city signed a five-year franchise agreement with Rocky Mountain Power. The previous agreement had been for 25 years. Salt Lake City also became the first municipal customer in a new Rocky Mountain Power solar program.
“Cities are a natural focus for renewable energy policies,” said the Sierra Club’s Rohrbach. “What cities provide is an opportunity for their leaders to be advocates . . . Ultimately what it comes down to is the cities are leveraging their buying power and their political will.”
While cities may attain a real or virtual 100 percent renewable target, whether the entire nation can meet that goal is an unsettled question and one that has provoked controversy, most notably in dueling papers in the Proceedings of the National Academy of Sciences that led to a Twitter storm that engulfed both scientists and the media.
The most comprehensive study on high penetration of renewables nationally was done by NREL in 2012. It concluded an 80 percent renewable energy grid was possible.
To get there would take a doubling in the pace of installing renewable energy sources and then doubling it again, and an investment of between $320 billion and $1 trillion above the utility industry’s baseline investment of $4 trillion.
The question of getting from 80 percent to 100 percent, just as it was for Aspen, becomes tricky, and that is where the conflict is.
The source of the technical fight was a 2015 paper by Stanford University professor Mark Jacobson. The Jacobson analysis argued that all power needs in the U.S., this includes transportation, could be met with electricity from renewable sources—wind, solar and hydro—with a stable grid and at a low cost.
In June, a paper disputing Jacobson’s conclusions appeared in the academy proceedings by a group of researchers led by Chris Clack, a former National Oceanic and Atmospheric Administration (NOAA) scientist and now CEO of renewable energy software firm Vibrant Clean Energy.
The paper attacked Jacobson’s work, saying it “involves errors, inappropriate methods, and implausible assumptions.” Much of the critique centers on questions of modeling and assumptions, such as a dramatic increase in hydropower.
Jacobson charged that his critics were nominally representing interests such as the nuclear power industry. Clack said that even when shown errors, Jacobson refused to modify his plans and rejected the claims that they were backing nuclear power.
The Jacobson analysis used a modeling tool called LOADMATCH, which is designed to match demand and supply. In that exercise the, program showed that renewable electricity could be supplied for about 11.37 cents a kilowatt-hour.
That is more than the conventional electricity cost of 10.6 cents a kilowatt-hour, but the Jacobson analysis includes savings in curbing pollution and its impacts on health, as well as cutting greenhouse gas emissions.
“It is a simplistic supply-and-demand model,” Clack said in an interview with GTM Research. He contended that only a comprehensive grid-integration study, identifying where on the system renewable generation is located, can determine how much renewable energy the grid can handle and at what cost.
“At 80 percent, it is reliable. When you get to 100 percent, you just don’t know if it is reliable,” Clack said. “Once you go up over 80 percent, the costs are very high.”
There isn’t a comprehensive grid balancing study, said NREL’s Doris. “We don’t have it,” she said. “How do you prioritize those investments? That would be well informed by a study of what is the most viable and economical.”
Jacobson stands by his work. “We are saying this is technically possible,” he told GTM Research in an extensive interview. “Whether it is a good idea or not is a political issue.”
Jacobson said his research group is now working on 100 percent renewable plans for 35 cities. “The blueprint part is we would like countries, states and cities to adopt the goal of 100 percent clean renewable energy by no later 2050, with 80 percent by 2030.”
“We realize the end result will not look like what we propose,” he said. “We are just saying here is one way to do it. There are multiple ways . . . as you get close to 100 percent, you will sort out the remaining details.”