Why energy footprint should be part of every climate conversation

Ontario is facing a twin challenge: a growing demand for electricity and a shrinking supply of undeveloped land. By 2050, electricity needs are projected to rise by 75%, driven by electrification, population growth and the development of new industries.

Meeting that demand will require a massive build-out of clean energy infrastructure.

But where will it go?

Conversations about electricity sources often focus primarily on cost, emissions or reliability. One critical factor is frequently overlooked: land use.

Solar farms, wind turbines and nuclear generating stations all have dramatically different spatial footprints. And in a world of competing land demands, including housing, agriculture and conservation, space is not a neutral or unlimited resource. If we want to expand clean energy without displacing communities or ecosystems, we must ensure land is part of the conversation.

Comparing the land-use intensity of electricity

We compared three clean energy technologies:

• Nuclear

• Solar (ground-mounted photovoltaic)

• Wind (onshore)

To assess their spatial impacts, we used a metric called land-use intensity of electricity (LUIE), which is the number of hectares needed to produce one terawatt-hour (TWh) of electricity per year. The lower the LUIE, the more efficient the technology is in terms of land use.

LUIE data for solar and wind comes from a 2022 study by Lovering et al., which analyzed dozens of real-world facilities using satellite imagery, public records and geospatial analysis. Nuclear data is based on the Bruce Power site in Bruce County, Ontario—one of the largest nuclear generating stations in the world.

Key assumptions from the data:

• Nuclear: The Bruce Power site, including the natural lands around the generator buildings, occupies approximately 930-932 hectares and generates ~45 TWh per year. This translates to a LUIE of 20.7 ha/TWh/yr.

• Solar:  Datasets included operational ground-mounted photovoltaic facilities in 18 US states. Land use calculations include panel areas, access roads and ancillary infrastructure.

• Wind:  Land use includes the footprint area (the land physically covered by turbine pads and access roads) as well as spacing between the turbines. In most cases, the spacing area can support other uses, such as agriculture. However, as turbines require a minimum spacing distance (7–15 times the rotor diameter for optimal performance) which may preclude the use of the land for other purposes such as housing or high-density development, this area remains a relevant part of the land-use calculation.

Land requirements by energy source

To compare across technologies, we looked at two scenarios:

1. Generating the same output as Bruce Power (45 TWh/year)

2. Meeting Ontario’s current annual electricity demand (137 TWh/year)

Source	LUIE (ha/TWh/yr)	Land for 45 TWh/yr (ha)	Land for 137 TWh/yr (ha)
Bruce Power Nuclear Generating Station	20.7	932	2,837
Solar (ground photovoltaic)	2,000	90,000	274,000
Wind (footprint only)	130	5,850	17,810
Wind (with spacing)	12,000	540,000	1,644,000

Nuclear is nearly 100 times more land-efficient than solar, and nearly 600 times more efficient than wind when turbine spacing is included.

What this means for Bruce County and SON Territory

Bruce County spans roughly 4,067 sq km and lies within the Territory of the Saugeen Ojibway Nation (SON), which encompasses around 8,093 sq km. The Bruce Power site occupies just 0.2% of Bruce County and 0.1% of SON Territory while producing 45 TWh annually.

Here’s how much land would be required by other energy sources to produce the same output:

Source	Percentage of Bruce County region	Percentage of SON Territory
Bruce Power Nuclear Generating Station	0.2%	0.1%
Solar (ground photovoltaic)	22.1%	11.1%
Wind (footprint)	1.4%	0.7%
Wind (spacing)	132.5%	66.7%

The bigger picture

Land use may not dominate headlines, but it will shape the long-term sustainability of our energy transition. As electricity demand grows, land-use conflicts will only intensify. New homes, expanded farms, protected habitats and industrial zones all require space, and energy infrastructure must fit into this already crowded landscape.

Nuclear energy remains unmatched in its ability to deliver baseload electricity with minimal land disruption. Generating the same output with wind would require turbines across the entirety of Bruce County, and then some.

Choosing power sources that are dense, efficient and respectful of land constraints is not just a technical decision, but also a planning imperative.

And for a province trying to reconcile decarbonization with development, that matters.

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Dr. Stephanie Keating is Director, Environment, part of the Bruce Power Nexus Research Centre.