Dell has stopped shipping certain highly energy-intensive gaming computers to customers in six states with new electricity consumption regulations.

The PC giant won’t ship certain computer models to California, Colorado, Hawaii, Oregon, Vermont, and Washington because of the states adopting the California Energy Commission’s new Tier II mandatory energy efficiency standards on computers and mobile gaming systems that were put into effect on July 1.

“This product cannot be shipped to the states of California, Colorado, Hawaii, Oregon, Vermont or Washington due to power consumption regulations adopted by those states. Any orders placed that are bound for those states will be canceled,” Dell’s website says regarding certain computers.

Dell confirmed to the Register on Monday that the shipping restrictions were due to the new power consumption regulations, saying that only two of its computer models, the Alienware Aurora R10 and R12, have been affected.

In order to comply with California’s and other states’ energy requirements, Dell now offers a special version of those two computer models, which adhere to the new regulations, so customers can still purchase those products.

The new regulations have been put in place due to energy supply and environmental concerns.

A study conducted by the Semiconductor Industry Association in 2015 found that computing will not be sustainable by 2040, when the energy required for computing will exceed the estimated world’s energy production.

Dell did not respond to a request for comment.