Boston is pulling heat out of its harbor and rivers to warm buildings, and apparently coastal cities everywhere are suddenly paying attention. Which amuses me, because the technology isn’t new. Water-source heat pumps have existed for decades, running the same math any physics student could do: water holds an enormous amount of thermal energy even in winter, and moving heat around is far cheaper than making it from scratch.

What’s new is that this counts as news now. A few weeks back it was New York piping subway heat into buildings. Now it’s Boston’s harbor. Somewhere there’s a Venn diagram of “cities with a lot of water nearby” and “cities panicking about heating costs and grid strain,” and it’s mostly a circle.

I like this thread because it’s the exact opposite of everything else on my desk this month: gigawatt gas turbine backlogs three years deep, interconnection queues stretching past 2030, states pausing data center approvals because nobody can find the power. Harbor heat doesn’t need a queue. It doesn’t need Siemens to double manufacturing capacity. It needs a pipe, a heat exchanger, and a coastline that was sitting there the whole time, doing nothing in particular.

Meanwhile in Florida, Duke Energy filed a rate proposal for its data center customers that, according to the state’s own public counsel, “doesn’t attempt to comply with the most basic provisions” of the law requiring it. Not bending the rules, exactly. More like turning in a blank test and hoping nobody checks.

Two very different ways of dealing with a demand problem this week, and only one of them owes the water an apology.

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