100% clean electricity: Can Iowa’s capital make history?

By Jeffrey Tomich | 12/11/2020 07:12 AM EST

Des Moines is aiming to be the first U.S. city to run on 100% clean power around the clock. What does it mean for the grid and President-elect Joe Biden’s goal to eliminate carbon emissions from the electricity sector?

Downtown Des Moines, Iowa, is shown at night in this January 2013 photo.

Downtown Des Moines, Iowa, is shown at night in this January 2013 photo. Jason Mrachina/Flickr

Nine states, more than 150 cities and hundreds of companies of all sizes have adopted 100% clean energy goals, with the most ambitious striving to meet those targets by the end of the decade.

Then there’s Des Moines, Iowa. The city of 216,000 isn’t yet part of the 100% club, but the City Council is weighing adoption of a resolution that would see it run on carbon-free energy around the clock by 2030.

The distinction is important because other cities with 100% renewable targets are trying to accomplish an easier goal — to offset energy use with renewables but fall back on fossil fuels to keep the lights on when needed. By contrast, moving to clean energy 24/7 would mean ditching fossil plants entirely and would likely involve billions of dollars in new investment in battery storage and zero-carbon electricity.


If adopted, however, Des Moines’ goal would represent perhaps the boldest climate-focused energy policy of any U.S. city and would further President-elect Joe Biden’s goal of eliminating carbon emissions from the nation’s power grid by 2035.

A 24/7 clean energy goal would appear to be a first for any U.S. city.

The Des Moines Council discussed the resolution during a two-hour work session Monday, a meeting that included local utility MidAmerican Energy Co. A vote could come later this month, according to Josh Mandelbaum, the council member who’s leading the effort.

The idea is ambitious, to be sure, and it faces opposition. Two council members indicated they won’t support the resolution as written. And MidAmerican said adding enough renewable energy capacity and battery storage or small modular nuclear generation to power the city with carbon-free energy around the clock would cost billions of dollars and lead to a sharp increase in electric rates.

Lori Bird, who tracks decarbonization pledges by cities and other large energy purchasers as director of the U.S. Energy Program for the World Resources Institute, said she isn’t aware of another city that has yet established a carbon-free energy goal.

But what Des Moines is considering fits with a broader trend among large energy buyers, who are increasingly setting their focus on decarbonizing the grid rather than just adding new renewable energy capacity.

Tech giant Google made news two months ago when it announced its goal to power operations globally, 24/7, with carbon-free energy.

"Large buyers are thinking about the next generation of clean energy purchases to see how we get the whole grid to decarbonize: What are the different things that are needed to get to net-zero emissions?" Bird said. "That’s what Google is trying to address."

To be sure, Des Moines, which has an annual budget of about $730 million, isn’t Google, whose parent company, Alphabet Inc., had over $160 billion in revenue last year.

In an interview with E&E News, Mandelbaum, who in his day job is an attorney for the Environmental Law & Policy Center, a Midwest advocacy group, conceded that it may be necessary to extend the end date for the goal to 2040 or even 2050 to get other council members "comfortable" with the resolution.

Mandelbaum also said it’s unlikely that the target would be included in the city’s future electricity agreements with MidAmerican.

But he said he’s not backing off from the need for the city to establish a stretch goal as it develops a strategy to confront climate change, the effects of which have been all too evident in recent years.

From more frequent and intense rainstorms and flooding to heat waves, a warming climate has already imposed massive costs, both on Des Moines and on Iowa’s mainstay agriculture industry. In August, a "derecho" storm saw wind gusts in excess of 110 mph and caused four deaths and billions of dollars in damage across Iowa and the Midwest, though scientific links between the frequency of the destructive thunderstorms and climate change are unclear (Climatewire, Oct. 5).

$8B price tag

The pursuit of an ambitious CO2-free electricity goal for Des Moines grew from a clean energy initiative by a statewide advocacy group, the Iowa Environmental Council. The group published an analysis in April showing the scale of wind, solar and battery storage energy needed to reach 100% renewable electricity in Iowa by midcentury.

The study showed that Iowa, a national wind leader with more than 10,000 megawatts of capacity installed, would need between 30,000 and 61,000 MW of wind and a minimum of 5,000 MW of solar to eliminate coal and natural gas from its electricity fuel mix.

But using those numbers, MidAmerican officials told the council that the 24/7 clean energy goal in the resolution would impose massive costs on residents.

Statewide, the utility estimated, making Iowa’s electricity generation zero-carbon around the clock would cost $54.7 billion to $126.9 billion, or $17,000 to $40,000 per resident based on current technologies. That doesn’t include the cost of additional transmission and distribution power lines.

For Des Moines, which represents about 10% of MidAmerican’s load, the utility estimates 24/7 renewable energy and lithium-ion battery storage would cost $8 billion and require a swath of land the size of the state Capitol complex — about 10 square city blocks — to site batteries. To achieve the goal with small modular nuclear reactors (SMRs) would cost as much as $2 billion, said Mike Fehr, MidAmerican’s vice president of renewable generation.

Residential customers, Fehr said, would see bills rise 50% if the utility pursued the SMR scenario and nearly quadruple if it relied solely on renewables and battery storage. Bill impacts for commercial and industrial energy users could be even greater, he said.

For their part, MidAmerican officials say they’re not dismissing council members’ clean energy ambitions.

The utility, with 696,000 Iowa customers, said it shares those goals and is working to achieve a carbon-free power system.

"We think our track record speaks for itself," utility spokeswoman Tina Hoffman said.

MidAmerican, owned by a holding company controlled by Warren Buffett’s Berkshire Hathaway, has its own renewable energy goal established in 2016.

The utility is on track to produce enough renewable energy by 2025 — mostly wind — to offset 100% of its customers’ energy use. It will reach 83% of its goal this year, according to preliminary numbers, and the utility expects to be at 90% next year, all while keeping rates well below the national average.

"Simply by being our customer, by being in Des Moines, every customer gets 83% of their energy from renewable resources," Kathryn Kunert, vice president of economic connections and integration at MidAmerican, told the council.

Most of the renewable energy comes from MidAmerican’s 30-plus wind farms, representing more than 7,000 MW. The utility is also adding solar capacity and a battery storage pilot project. But sustainability must be balanced with reliability and affordability, Kunert said.

"Because the wind doesn’t always blow and the sun doesn’t always shine, our renewable assets cannot be relied upon to provide the consistent and reliable power our customers need," she said.

Repeating the impossible

For that guarantee of reliability, MidAmerican has looked to another part of its generating portfolio: a fleet of six coal units.

Indeed, while environmental advocates largely praise the company for aggressively adding wind capacity, they’re also sure to note that the expansion of wind in Iowa over the last decade hasn’t always translated into an equivalent drop in carbon emissions.

"Expanding wind clearly doesn’t necessarily mean falling emissions," said Kerri Johannsen, energy program director for the Iowa Environmental Council.

The group’s April report showed that despite more wind power continuing to be added, coal is still a substantial part of Iowa’s electricity mix, and power-sector greenhouse gas emissions have actually risen in each of the past two years — a fact it attributes to the 706-MW Marshalltown natural gas plant and Iowa coal plants, which are selling some of their output into the broader regional market.

MidAmerican officials acknowledged on Monday that the company’s coal plants could continue to run and pump out carbon emissions even as the utility reaches its 100% renewable goal.

In fact, part of the debate at Des Moines’ City Council this week echoed a national discussion: How do you get from a high concentration of wind and solar to a 100% carbon-free power grid? It’s a question that becomes more important as automakers shift from gasoline and diesel-powered cars and trucks to electric vehicles.

Bird of the World Resources Institute said it remains to be seen if existing technologies are enough to fully decarbonize the grid, or if technologies such as next-generation nuclear, green hydrogen or carbon capture will have to play a role. The answer could vary regionally, she said.

"But it’s going to be more cost-effective to get to net zero if there are some firm, dispatchable resources on the grid," said Bird, who is also a former analyst at the National Renewable Energy Laboratory.

Mandelbaum said he believes MidAmerican’s rough cost estimates are "inflated" and cites data from investment bank Lazard to suggest there’s also a compelling economic argument for further ramping up renewable energy: namely, that adding new renewable energy capacity, which has no fuel costs, can be cheaper than continuing to maintain and run existing fossil fuel plants.

He and other supporters of the 100% clean energy goal don’t dispute that getting to a carbon-free electric system for the city will require significant investments and come with challenges. But they argue that fretting about the scale of the task misses the point of establishing a goal and beginning to work toward it.

"We’re not demanding this happens tomorrow," Johannsen said. "But if we’re going to be where we want to be in 10 years, we need to start planning today."

Mandelbaum said if someone had proposed 10 or 15 years ago that 80% of energy sold to MidAmerican customers would come from renewables, they would have been told it was impossible.

"But here we are," he said. "MidAmerican has pushed further than anyone would have thought possible 10 years ago. We are confident, with the right policy levers in place, they can do it again over the next decade."