Calvert Cliffs will add 190 MW by 2032 under a 20-year Amazon power contract

A capacity planner with racks in the PJM footprint reads about Amazon's 690 MW on Monday and wants to know whether that power just left the market. It did not. According to the companies' release as reported by Interesting Engineering, all the electricity Calvert Cliffs generates will keep flowing to the PJM regional grid just as it does now ^[11].

The pitch is clean power and a stronger grid. "Amazon is committed to investing in carbon-free energy to strengthen the grid and benefit the communities where we operate," said Kerry Person, vice president of AWS Global Operations and Data Center Delivery ^[10]. Joe Dominguez, Constellation's chief executive, framed it as an investment story. "This agreement demonstrates how private investment can strengthen critical energy infrastructure," he said ^[9].

Of the 690 MW, 500 MW is power the plant already makes and 190 MW is new, so about 28% of the contracted volume is added generation ^[21][22]. The companies say the agreement will help Amazon manage its energy costs for facilities across the region ^[12]. Measured against the plant, the contract is large. Interesting Engineering rates Calvert Cliffs at 1,790 MW and DCD at 1.78 GW ^[5][6]. On the larger figure, Amazon's 690 MW is about 39% of current capacity, and the uprate adds about 11% ^[19][20].

Interesting Engineering sets the deal against electricity demand rising quickly, particularly from data centers and AI ^[17]. Neither account discloses what Amazon pays. Without a price, the contract shows that Amazon will commit for two decades to power whose new portion is years away, and it shows little about what power will cost other buyers in the 2030s.

Amazon's own Maryland plans are moving in several directions, according to DCD. A campus at TPG's Quantum Frederick Park in Adamstown is under development ^[14], and the company recently bought an office and data center site outside Baltimore in a sale-leaseback with T. Rowe ^[15]. Its Fastnet cable to Ireland is set to land in Ocean City, where local moratoriums against data centers have taken effect ^[16].

The easy assumption on reading a hyperscaler nuclear headline is that a rival has locked up dedicated supply. Two questions test it. The first is whether the power goes to the buyer's own sites or stays on the shared grid. The second is whether the new megawatts arrive before or after your own need date. Grid-delivered and late, where Calvert Cliffs sits, means the buyer gets a cost arrangement and the grid gets new supply from 2030 ^[3]. Grid-delivered and early adds supply in time to help everyone on that grid. Dedicated and early should change your plans, because a competitor has taken power you could have bid for. Dedicated and late goes in the 2030s planning file.

I'd log Calvert Cliffs in the grid-delivered, late box and count its 190 MW only from the year it comes online. The tradeoff is that this treats the deal purely as supply. It sets price aside, and the contract's cost terms belong to Amazon alone ^[12].