Texas law splits land rights into two categories: surface estates and mineral estates. In places where oil and gas activity has been common, this makes sense. The mineral rights to a given amount of land—that is, the under-the-surface resources that can be developed—have a distinctly different value to the property than the right to what’s on the surface, where people can live/graze cattle/grow crops/etc. But as we enter a bold new energy frontier, West Texas property sales are now looking to add a new category: that of the “wind estate.”

KUT talked to a prospective land buyer who discovered this while browsing property online:

Trey Murphy is a grad student in North Carolina, but he has dreams of owning land in West Texas. A few months ago, he was looking at real estate online and came across something strange.

“I saw that there was this particular listing that was selling the surface estate, but not willing to sell the wind estate,” he says.

Most people would have no idea what that means. But Murphy is originally from Texas, and, as luck would have it, he studies “energy geography.” He knows that in Texas, one tract of land can be owned in different ways by different people.

Texas law currently has no definition of “wind rights,” but, as a title lawyer the radio station spoke to notes, property deeds are notoriously flexible in Texas, so there’s no reason a landowner looking to sell couldn’t declare substitute the word “wind” for “mineral” in a deed stating “mineral rights do not convey.”

Where it gets trickier is what that means in practical terms. Windmills sit on the surface, after all, and while Texas law is fairly explicit on how mineral and surface rights interact. Generally speaking, ties go to the mineral rights owner, which has the right to “reasonably necessary” use of the surface in order to exploit the mineral resources—they can enter the property, build roads, store equipment, install pipelines, and more, to ensure that they’re able to access the portion of the property that they own. There’s no clarity about how that would apply in regards to wind rights.

This isn’t the first time this has been raised—it’s just that, as wind power occupies a more significant part in the Texas energy portfolio, the questions now carry more urgency. In 2007, the State Bar of Texas’s Oil Gas & Energy Resources Law Section Report published a paper called “Undertaking the Severance of Wind Rights” that addressed whether this was even possible in the state (it is). The specifics of how those rights break down—if the surface rights or the wind rights owner will have the ability to determine where windmills should be placed, say—is an open question still. But its one whose answers are likely to be determined in court in the not-too-distant future, as deeds that carve out this exception become more common.