Estate Step-up in Basis & Wind Energy

Client recently inherited farmland, some of the land has oil/gas mineral rights and other land has wind turbines. I understand the land itself receives a step up in basis as well as the oil/gas mineral rights but what about the wind energy? The client wants to sell the revenue stream from wind energy, hence the question. A CPA in the office argues that its similar to the mineral interests and he'd have basis. I see how wind turbines could increase or decrease the value of the land itself. I just can't wrap my head around something like wind energy having basis. Has anyone run across this before? Can you point me in the right direction to research?

Doesnhe own the turbines, or does he grant a lease or easement to a company that owns them?
Either way, I don't see why iys value is not stepped up at death.
He'd be selling his asset, either tangible or intangible. The underlying revenue stream may be the way to value it, bit it's not what he'd be selling.

You might want to look at the discussion we had about inherited book royalties.

viewtopic.php?f=8&t=8139&p=77091&hilit=author+ird#p77091

He leases to the company that owns them.

Thanks, I'll read the referenced discussion!

If he leases to the company that owns the turbines, would there not be either an easement to allow that company to build or install them on his land and to have access to them? Or even (unlikely) a piece of the land separately carved out (by sub-dividing)? And I wonder if it matters whether the lease is for a flat annual amount, or contingent on something. And I wonder whether the easement is perpetual or for a fixed number of years. And I wonder what happens to the turbines when the lease ends.

What I'm getting at is that he'd need to sell the easement/piece of land, which itself has value and should be stepped up.
And he'd sell the rights he has as lessor to collect future rents. The value assigned to thode rights would depend on the terms of the lease.

But from what I see so far, I don't see IRD.