Energize CT and the Constellation website explains how it works. They don't buy from Eversource, they buy from the actual energy companies at auction. They bought credits a while ago and can resell at that lower rate.

They still have a markup but as others have said it's a different business with different operating costs.

https://www.constellation.com/energy-101/energy-choice/what-is-energy-deregulation.html

>As of April 1st, 2020 our seaplane operations have ceased to operate. 

Am I missing something?

It happened for a bit last year too. I made weekly trips to the gas station to keep my heat going. Right now I see heating oil between $5 and $5.25 or so, and diesel around $5.75.

One is profits. Oil companies take a percentage of the cost in profit. 15% of $2.50 is $0.37, but 15% of $5 is $0.75. Yet we have to buy the same number of gallons to heat our homes. You'd think heating oil and diesel would come from the same places though.

Supply chain lag? I'd think most local oil companies are dealing with a lot more volume than your local gas station.