Looking for a quick fix for their fast-growing electricity diets, tech giants are increasingly looking to strike deals that would let them plug directly into power plants.

It’s raising questions over whether diverting power to higher-paying customers will leave enough for others and whether it’s fair to excuse big power users from paying for the grid. Federal regulators are trying to figure out what to do about it, and quickly.

Front and center is the data center that Amazon’s cloud computing subsidiary, Amazon Web Services, is building next to the Susquehanna nuclear plant in eastern Pennsylvania.

The arrangement between the plant’s owners and AWS — called a “behind the meter” connection — is the first such to come before the Federal Energy Regulatory Commission. For now, FERC has rejected a deal that could eventually send 960 megawatts — about 40% of the plant’s capacity — to the data center. That’s enough to power more than a half-million homes.