(Photo by Sarah Barrow via Creative Commons)

In Iowa, another view on how to solve wind’s variability

A groundbreaking renewable energy study is on the agenda this week at an annual gathering of the wind power industry in Iowa.

The analysis, which was published in the Journal of Power Sources, challenges the common notion that wind and solar power need to be paired with fossil fuel or nuclear generators, so utilities can meet electricity demand when it’s not windy or sunny.

The paper instead proposes building out a “seemingly excessive” amount of wind and solar generation capacity — two to three times the grid’s actual peak load. By spreading that generation across a wide enough geographic area, Rust Belt utilities could get virtually all of their electricity from renewables in 2030, at a cost comparable to today’s prices, it says.

The research is of particular interest to Midwest wind developers, who will hear from one of the study’s co-authors today at the Iowa Wind Energy Association conference in Des Moines. Cory Budischak, who teaches energy management at Delaware Technical Community College, is scheduled to speak at 9:35 a.m., immediately following Iowa Gov. Terry Branstad.

Budischak told Midwest Energy News that he started thinking about the topic after hearing a coal lobbyist claim wind could never replace a baseload power plant.

“I think this study really challenges that,” Budischak said.

Budischak and his colleagues used computer models to seek out the most economical mix of renewables and storage to meet electricity demand on the PJM Interconnection grid 30 percent, 90 percent or 99.9 percent of the time.

The team simulated 28 billion combinations of wind, solar and storage technologies using projected 2030 prices and historical weather and PJM load data from 1999 to 2002. (The PJM grid extends from Chicago east to New Jersey.)

The winning, most cost-effective combination turned out to be a whopping amount of wind power and surprisingly little storage.

The analysis found that wind power alone could meet all of the grid’s power needs 90 percent of the time if utilities over-built wind generation capacity to equal about 180 percent of peak load — around 140 gigawatts in PJM’s case.

By comparison, Iowa currently has about 5 gigawatts of wind capacity installed, with a potential wind resource of 570 gigawatts, according to the Wind Energy Foundation.

Under the study’s scenario, on windy days, thousands of megawatts of clean electricity might go to waste, but even on the worst-performing days there would be enough power from wind farms to meet all or most of the demand.

Renewables could meet demand 99.9 percent of the time by adding solar and storage to the mix and ramping up renewable generation capacity to around 290 percent of peak load.

The remaining 0.1 percent of hours could be covered by fossil fuel power plants, but if they become uneconomical to maintain, other mechanisms such as demand management, interruptible rates or other storage could close the gap.

Both systems, without subsidies, would cost less than the current one — if externalities such as health and environmental impacts are accounted for, the paper says.

The more-is-better strategy can be almost as effective as storage at smoothing out wind power’s peaks and valleys, but at a fraction of the cost, it concludes. By having more wind farms spread across a wide area, the odds of them all coming to a standstill at once diminish.

It’s a new way of approaching the challenge, Budischak said. Previous studies have looked at how to achieve significant renewable penetration, but they’ve focused on how to generate the amount of electricity we use, but no more. This study lifted that cap.

On the surface, it might seem wasteful, but the paper points out that today’s thermal fossil fuel power plants are far from efficient, and Budischak notes that the surplus power would be from a fuel-free source. “We’re not paying for the wind to blow or the sun to shine,” he said.

It’s also possible that the surplus generation could be used for electric heating, which could further improve the economics, he said. Wind generation tends to be higher and electricity use lower in the winter.

For Iowa, he said, the analysis could support efforts to expand the wind industry’s role.

“They can start to make the argument that this isn’t just something for 10 or 20 percent of our portfolio mix. We can really get to those higher percentages.”

10 thoughts on “In Iowa, another view on how to solve wind’s variability

  1. Hi Dan, Cory:
    This is exactly my conclusion as outlined in my paper “Green RE-Heat: Integrating Wind Power and Thermal Energy Storage as the Least-cost Retail Energy Option”, that is we need roughly three to four times peak wind capacity of the averge electric utility load to make a 100% renewable energy powered community, big or small. Add solar PV peaking power and it’s a no brainer. On ward.


  2. The ultimate pipe dream. On cold winter days in the United Kingdom, all those turbines struggle to operate at a 10% capacity factor.

  3. So what you’re saying is we need to cover every acre of corn ground in Iowa,Minnesota, South Dakota, Nebraska, and Kansas with windmills. Then we need powerlines up the wazoo to take this energy to the east coast states.

    Why don’t we just fill Lake Michigan up with windfarms and all down the east coast. Cape Code is great place for wind!

    Seriously, this report is absurd. Iowa has a potential of 570 gigawatts of wind energy. Where is Iowa going to grow corn and soybeans?

    140 gigawatts of windmills would cover over 7100 square miles of windfarms. Seriously, people do live in Iowa. At what point do wind turbines become pollution of its own.

    Making the state into one big windfarm for PJM is absolutely asinine.

  4. I’m a little confused by your math. 140 GW would mean about 47,000 (3 MW) wind turbines. Each wind turbine has a footprint of about a quarter-acre, so a total of 11,750 acres, or about 18.4 square miles, would be taken out of production. Yes, the actual wind farms themselves would be much larger, but you can farm in between the turbines.

    How on earth do you get to 7,100 square miles? And where did you get the idea that someone wants to turn Iowa into the sole power source for the PJM? The paper isn’t a policy proposal.

    The PJM, incidentally, covers 214,000 square miles, so even if we roll with the 7,100 square mile figure, that’s only 3% of the territory covered by wind farms. A lot of land, no doubt, but not quite the impact you’re making it out to be.

  5. The choice between nuclear and renewables will be very regional. The utility below should be considering more low carbon power and converting the old 1000mw coal to either: 1. more ND wind,solar,hydro,CCGT’s 2.same as 1 but broader regional wind per above article 3. same as 1 but nuclear instead of CCGT’s 4. no more wind,solar,hydro but 100%nuclear. The mining and wood product industries, which use close to 50% of their output, could care less how the power is produced, just that it’s cheap. The residents of the area would be very divided and could easily vote for number 1 or 2 even if it costs more. Right now coal is cheap form North Dakota or Wyoming so coal wins the day without carbon cost. Kansas and Nebraska are envious of Iowa’s leadership in wind.
    Minnesota Power In NE Minnesota just filed there 10 year resource plan to the PUC. They decided to shut down two smaller coal plants rather than install emission controls minus CO2. The big Boswell “base-load” coal plant at around 1000mw will continue to burn coal from most likely the parent companies coal mine in North Dakota. . Also have 400mw of North Dakota wind with 100 to 200mw more planed. Some hydro existing but 250mw of Manitoba hydro planed. Over the next decade they do plan to incorporate natural gas generation first to fire existing boilers then CCGT’s to the ultimate goal of 1/3 coal,1/3 gas, 1/3 renewables, but only as load increases. To keep the 54 year old Boswell plant going, some $350 million will need to be spent on emission hardware not counting CO2 of course. So unless there is a cost of carbon,it will take maybe two decades to reach this goal. Seems they should just accelerate there plan by shutting down the 1000MW coal spending the $350 million on CCGT’s and more renewables This seems like the classic case you explained above to replace coal with CCGT’s since I believe they have the gas available.

  6. You can farm between the windmills. But you would also be busy picking up all the dead birds and bats, as there would be few left alive in Iowa.

  7. Below is the latest form Certs news letter part of MN Office Of Energy Security/Commerce Dept.

    “One way they do this is through adding forms of renewable energy to the power grid. Currently in Minnesota and the Midwest, wind is the most abundant clean energy resource. In addition to wind, we also utilize biomass power from trees, animal waste and plant matter, and hydropower from flowing water. Over the past several years MISO has been integrating more wind power initiatives into the power grid, and we dug a little deeper to find out what this means for Minnesota.

    On November 23rd, MISO announced that they had reached 10,000 megawatts (MW) of wind power overnight, which put them past the 10 gigawatt hour (GWh) mark for production of wind energy. At that same time, it was reported that wind energy accounted for 25% of the energy being used. According to MISO, total wind capacity has grown dramatically in the last seven years due to a national desire for cleaner energy, as well as mandates for renewable energy options.

    So, what does this mean for us? We know that the Midwest has some of the strongest and most consistent wind patterns in the nation. We also know that installation of infrastructure for wind farms can be fairly costly and that harnessing the wind through wind farms can sometimes be fairly inefficient. In order for consumers to benefit from wind energy, MISO is currently undergoing a solution-based process for addressing the operational challenges of harnessing the wind in their footprint. In January of 2010, MISO began working with stakeholders to design and implement a market strategy to take into account the current and projected increases of wind generation in their footprint and make the “concept of non-dispatchability less applicable.” Through the introduction of Dispatchable Intermittent Resources (DIRs), MISO will be able to allow resources such as wind to participate fully in energy markets.

    As MISO plans for a future of increased wind generation, they continue to actively forecast wind resource output at five-minute and hourly intervals, while working toward enhanced methodologies and accuracies in order to benefit from our most promising renewable energy resource—wind.”

  8. Place wind turbines next to large bodies of water and on days with excess wind power, split water into hydrogen gas to store and use in gas turbines when the wind doesn’t blow.