Utility-scale Wind and Solar Development in Iowa: Trends, Prospects, and the Land Factor

By Jian Chen and Hongli Feng

In 2020, Iowa ranked first in the United States for percentage of state electricity produced by wind energy, which supplied 57% of the state’s net electricity generation (IUB 2022). Conversely, in 2020, solar energy had a limited role in Iowa’s electricity generation, supplying less than 0.04% of the state’s net electricity generation (IUB 2022), which ranked 43rd in the United States.

In this article, we investigate the stark development and generation disparities between wind and solar energy in Iowa. We focus on utility-scale power plants only, meaning that compiled data applies to power plants that have a relatively large nameplate capacity (one megawatt (MW) is often used as a cut-off value).

Historical wind and solar photovoltaic development

Understanding the development of utility-scale wind and solar energy is pivotal since utility-scale wind and solar power plants accounted for 95.5% of Iowa’s wind and solar power plants under operation as of November 2021, and the continued growth in wind and solar energy in Iowa will rely on more utility-scale wind and solar deployment.

Wind electricity generating capacity in Iowa has flourished since its first operable utility-scale wind power plant emerged in 1998 (figure 1). As of November 2021, Iowa operates 141 utility-scale wind power plants that possess a nameplate capacity of 11,656 MW. The first operable utility-scale solar photovoltaic power plant in Iowa was established in 2016 (USEIA 2021). Between 2016 and November 2021, nine utility-scale solar photovoltaic power plants came into operation and aggregated a total nameplate capacity of 118 MW.

Wind and solar projects on the pipeline

According to the US Energy Information Administration’s “Inventory of Planned Generators 2021,” there are seven utility-scale wind power plants and six solar photovoltaic power plants on the pipeline at various stages of preparation from 2021 to 2030. These projects aggregate a total nameplate capacity of 995.8 MW, with 853.9 MW from utility-scale wind projects and 141.9 MW from utility-scale solar photovoltaic projects. Specifically, one wind project (55.4 MW) has completed construction but is not yet in commercial operation, two wind projects (200 MW and 80 MW) and one solar project (100 MW) are under construction that are less than or equal to 50% complete, three wind projects (7.9 MW, 202.7 MW, and 7.9 MW) and five solar projects (25 MW, 3 MW, 3 MW, 7.9 MW, and 3.9 MW) have completed more than 50% of construction, and one wind project is still pending for regulatory approval. Figure 2 shows the location and capacity of the planned utility-scale wind and solar projects, which shows a similar pattern between geographical locations and resource potentials (figures 4 and 5) compared with the current spatial distribution of utility-scale wind and solar projects.

Financial incentives and regulatory policies

Different factors contribute to the development and disparities between wind and solar energy. Government intervention related to financial incentives and regulatory policies is a critical factor that guides investment into certain renewable energy technologies. Financial incentives and regulatory policies vary between wind and solar energy in Iowa. Based on the Database of State Incentives for Renewables Efficiency (DSIRE), as of 2019, there were 25 federal and state wind programs and 30 solar programs. According to DSIRE’s categorization, financial incentives constitute 72% and 76% of total wind and solar programs, respectively, and regulatory policies constitute 28% and 24% of total wind and solar programs, respectively. Note that the number of policies does not represent the degree of support.

Government policies that aim to reduce barriers to entry heavily influence the development of energy, which is especially true for wind and solar. These policies include the Renewables Portfolio Standard (RPS), loan programs, grid-connection-like programs, net metering and interconnected standards, and tax-related credits and exemptions. On the one hand, as a technology-neutral renewable energy policy, RPS tends to favor wind energy because of its cost-advantage over solar power (Wiser, Barbose, and Holt 2011). On the other hand, Iowa does not have a specific solar carve-out embedded in the RPS design that could provide additional support for solar energy deployment. Iowa chose wind energy to satisfy its renewable mandate in 1983, and wind energy development has dominated solar energy development since then.

National renewable energy policies play critical roles in influencing the development rates of both wind and solar energy. Research shows that the federal Production Tax Credit (PTC) and Investment Tax Credit (ITC) have significantly increased the development of renewable energy (Lu et al. 2011; Dwivedi 2018), as spikes in development for both sources around the introduction and expiration of each credit promoted credit renewals. However, wind received more support than solar because solar energy is not eligible for PTC, whereas both wind and solar are qualified for ITC, making wind more preferable to utility companies. Wind and solar also receive state-level supports in Iowa in the form of financial incentives such as sales and property tax exemption and investment tax credits. The most recent legislation in Iowa, the 2020 Solar Bill, codifies net metering, allows electric utilities to bill customers under net metering or inflow-outflow rate, and calls for a potential “Value of Solar” study in the future. Although the bill aims to influence residential power, in contrast to the utility-scale power this research focuses on, the passing of this bill shows that Iowa’s policymakers recognize the social interests related to solar energy use and development across the state.

Land footprint of wind and solar energy

Figure 3 shows the geographical locations of current utility-scale wind and solar projects in Iowa. Unsurprisingly, the geographical distribution for current utility-scale wind projects largely overlaps the area with the highest wind resources in Iowa (figure 4). On the other hand, the majority of current utility-scale solar power plants reside in areas where the solar radiation is the lowest (figure 5). Nonetheless, we cannot tell if solar natural resources play a role in development location as there are only nine utility-scale solar projects and solar potential does not vary significantly across the state.

To further look at the land use characteristics of wind and solar projects in Iowa, figure 6 shows the map of average farmland value by county from 2000 to 2021. Combined with figure 3, we find that Iowa’s wind projects are primarily located in areas with high farmland values. In contrast, the nine current solar projects are mostly located in brownfield land and old manufacturing sites to reduce development costs. Wind turbines can co-exist with crops and some studies show they can have positive effects on crop yield (Kaffine 2019; Takle 2018) and farmland value (ILC 2019), whereas solar photovoltaic panels compete with crop production for land. Both wind turbines and solar panels also have environmental impacts related to land and soil (Armstrong et al. 2014; Thomas et al. 2018), and the impacts and perceptions of these impacts can influence communities’ attitudes, often significantly.

It is hard to compare the land footprints of wind and solar energy because many solar panels are concentrated in one field for a solar project whereas wind turbines are spread across fields. However, we can compare their land costs separately based on reports from various sources. According to Halvatzis and Keyser (2013), the average land lease payment per MW of wind turbine in Iowa is $4,000 per year, which is consistent with USDOE’s national average of $3,350 per year (USDOE 2022). Siting one MW of solar panels currently takes approximately 5–10 acres of land in Iowa (Ong et al. 2013) with per acre solar lease rates ranging from $600–$1,100 (ISETA 2020; IFT 2021), implying an annual land cost of $3,000–$11,000 for installing one MW of solar capacity. Therefore, the land cost of solar in Iowa can be comparable to wind but is likely to be greater than wind depending on per-acre lease payment and the number of acres used for each megawatt of power generated. At the rate of 5–10 acres of land for one MW of solar panel electricity, it will take about 60,000 to 120,000 acres of land to reach 11,656 MW of the current total wind capacity in Iowa, and an additional 4,250 to 8,500 acres of land for the 854 MW of wind capacity in the pipeline. To put the numbers in perspective, the 2017 Agricultural Census indicates that Iowa has 26.5 million acres of cropland, of which about 1.6 million acres were enrolled in the Conservation Reserve Program averaged annually over the last 10 years. Both solar panels and wind turbines can have significant impacts on neighboring land and communities, which often results in heated local debates and eventual local regulations.

Local regulations on siting

Siting regulations, on a local level, guide and permit the development of renewable energy technologies. Not all Iowa counties have adopted zoning regulations—as of 2021, 21 of Iowa’s 99 counties have a utility-scale solar zoning ordinance, and 58 counties have a utility-scale wind zoning ordinance (table 1). The county-specific zoning ordinances are designed to deal with building specifications and restricted areas of construction and differ across counties in zoning stringency such as setbacks, ground cover, and decommissioning agreement. The clarity of utility-scale zoning ordinances reduces soft costs by eliminating the information uncertainty between renewable energy developers and local communities and reducing the risk and time associated with developers seeking siting locations for utility-scale wind and solar power plants. Therefore, a lack of clarity on utility-scale solar photovoltaic energy tends to hinder utility-scale solar energy’s development abilities in Iowa. Given the growing interest in solar and concerns over broader impacts, some counties have implemented a moratorium to allow time for regulation development. For example, on December 21, 2021, Johnson County enacted a temporary moratorium (until June 5, 2022) on utility-scale solar energy systems in unincorporated Johnson to review and discuss solar-related regulation (JCBS 2021). And on March 8, 2022, Green County approved a temporary moratorium on utility-scale solar farms for six months (Carison 2022). Moreover, to protect more productive farmland, Iowa lawmakers proposed a bill on February 15, 2022, that could limit solar panels to less productive farmland with a minimum setback distance of 1,250 feet from the nearest neighboring landowner (Peikes 2022).
 

A study conducted at Columbia Law School’s Sabin Center for Climate Change Law cites recent moratoriums enacted in Iowa to halt wind energy development in various counties (Marsh, McKee, and Welch 2021). Adair, Hardin, and Madison Counties enacted caps or moratoriums in 2019 that limit the amount of wind turbines in each county. These cases highlight the importance of local regulations on the development of solar and wind energy. Furthermore, contextualizing these moratorium cases may help reassess the narrative behind local ordinances. In the case of Adair County, 14 utility-scale wind projects created a cumulative 865 MW of nameplate capacity between 2010 and 2021. Over those 11 years, Adair County had the highest concentration of wind turbines in the state, which constituted 9.4% of Iowa’s total utility-scale wind nameplate capacity in 2021. With an influx of projects entering an already-developed wind turbine infrastructure, one could argue that Adair County’s cap is not surprising.

To sum up, wind energy has dominated utility-scale renewable electricity generation in Iowa in the last couple of decades and will likely continue to do so in the foreseeable future. Utility-scale solar projects have the potential to make Iowa’s electricity grid more diversified with its recent explosion of growth. With sustained support of government policies, and also expansion of counties that incorporate solar into zoning ordinances, Iowa will see continued growth of utility-scale solar. However, concerns over land use and related regulations will play a critical role in the development of both wind and solar energy in Iowa in the immediate future.

References

Armstrong, A., S. Waldron, J. Whitaker, and N.J. Ostle. 2014. “Wind Farm and Solar Park Effects on Plant–soil Carbon Cycling: Uncertain Impacts of Changes in Ground-level Microclimate.” Global Change Biology 20(6):1699–1706.

Carison, C. 2022. “Greene County Supervisors Approve Solar Farm Temporary Moratorium.”

Dwivedi, C. 2018. “Influence of Production and Investment Tax Credit on Renewable Energy Growth and Power Grid.” In 2018 IEEE Green Technologies Conference (GreenTech), 149–154. Piscataway: IEEE.

Halvatzis, S., and D. Keyser. 2013. “Estimated Economic Impacts of Utility Scale Wind Power in Iowa.” Technical report No. NREL/TP-6A20-53187. National Renewable Energy Lab.

Lu, X., J. Tchou, M.B. McElroy, and C.P. Nielsen. 2011. “The Impact of Production Tax Credits on the Profitable Production of Electricity from Wind in the US.” Energy Policy 39(7):4207–4214.

Iowa Farmer Today (IFT). 2021. “Too Early to Tell How Solar Farms Impact Land Value.”

Iowa Land Company (ILC). 2019. “Do Wind Turbines Increase My Iowa Farmland Value?”

Iowa Solar Energy Trade Association (ISETA). 2020. “Iowa Solar Energy Fact Sheet.”

Iowa Utilities Board (IUB). 2022. “Iowa’s Electric Profile.”

Kaffine, D.T. 2019. “Microclimate Effects of Wind Farms on Local Crop Yields.” Journal of Environmental Economics and Management 96:159–173.

Marsh, K., N. McKee, and M. Welch. 2021. “Opposition to Renewable Energy Facilities in the United States.”

Ong, S., C. Campbell, P. Denholm, R. Margolis, and G. Heath. 2013. “Land-use Requirements for Solar Power Plants in the United States.” Technical report No. NREL/TP-6A20-56290. National Renewable Energy Lab.

Peikes, K. 2022. “Iowa Lawmakers Advance a Bill Placing Restrictions on Solar Panels Built on Farmland.”

Takle, G. 2018. “Iowa State University Research Finds Wind Farms Positively Impact Crops.”

Johnson County Board of Supervisors (JCBS). 2021. “Moratorium On Utility-Scale Solar Energy Systems Greater Than 10 MW (AC) Is In Effect Until June 5, 2022.”

Thomas, K.A., C.J. Jarchow, T.R. Arundel, P. Jamwal, A. Borens, and C.A. Drost. 2018. “Landscape-scale Wildlife Species Richness Metrics to Inform Wind and Solar Energy Facility Siting: An Arizona Case Study.” Energy Policy 116:145–152.

US Energy Information Administration (USEIA). 2021. “2021 Form EIA-860 Data.”

US Department of Energy (USDOE). 2022. “Land-Based Wind Energy Economic Development Guide,” pp. 38. Accessed on 2/23/2022.

Wiser, R., G. Barbose, and E. Holt. 2011. “Supporting Solar Power in Renewables Portfolio Standards: Experience from the United States.” Energy Policy 39(7):3894–3905.

Suggested citation:

Chen, J. and H. Feng. 2022. "Utility-scale Wind and Solar Development in Iowa: Trends, Prospects, and the Land Factor." Agricultural Policy Review, Winter 2022. Center for Agricultural and Rural Development, Iowa State University. Available at https://agpolicyreview.card.iastate.edu/winter-2022/utility-scale-wind-and-solar-development-iowa-trends-prospects-and-land-factor.