Hernandez and colleagues publish new global study on the land footprint of energy systems and decarbonization scenarios

The authors find a range of land use intensity of energy across different energy types — spanning four orders of magnitude, from nuclear with 7.1 ha/TWh/y to dedicated biomass at 58,000 ha/TWh/y.

Highlights

Producing energy takes up land—a fact you could be forgiven for forgetting today. After all, the current energy system only occupies about 0.4% of ice-free land worldwide, most of it for hydroelectric power generation, a number dwarfed by agriculture, cities, and other anthropogenic land uses.

However, that balance is likely to change. In a new paper published in PLoS ONE, Jessica Lovering, Marian Swain, Linus Blomqvist, and Rebecca R. Hernandez, studied the land footprint of different energy sources, and our results are sobering. In a number of decarbonization scenarios, the land required for electricity generation expands by 30-80 million hectares. And that number grows to 80-800 million hectares if the spacing around the installations – for examp!e, the area between individual wind turbines – is included. This expansion is on the same order as the projected growth in global urban areas (60-241 million hectares), and not far from the growth in cropland area that could result from feeding a growing population eating higher up on the food chain (160-320 million hectares).

Let's take a step back and look at how the authors arrived at these numbers. The object of their study was the land-use intensity of energy, defined as area per unit of energy production, or more specifically, the number of hectares per terawatt-hour of electricity generation in a given year.

They calculated land-use intensity not through modeled or theoretical values for area and electricity generation, nor by just looking at a small number of facilities and extrapolating, but instead by using real-world data for a large number of energy facilities. In total, they applied 1,400 observations covering nine electricity sources—coal, natural gas, nuclear, wind, solar PV, concentrated solar, geothermal, hydroelectric, and biomass—across 73 countries and 45 US states. For some of these, they collected data from published studies, and for some they matched our own measures of area, assessed from Google Earth, to publicly available information on electricity generation. The authors included both the space needed for the power plants themselves (direct land use), and the space needed for upstream production of the fuels (indirect land use).

The study also makes a distinction between what they call "footprint" and "spacing" for natural gas and wind. Footprint area represents land directly covered by infrastructure, while spacing area is the entire area within the perimeter of a production site. For wind, for example, the footprint is just the area of the turbine pads and access roads, whereas the spacing is the area of the whole wind farm.


Guillermo Jimenez