The Market Florida Almost Has: SEEM and the Midday Solar Surplus

I. What SEEM actually does

SEEM matches willing sellers and buyers of surplus power in fifteen-minute windows, using whatever room is left on existing transmission lines. The design is deliberately narrow. It is a bilateral market (each trade is one seller paired with one buyer, not a single pooled price for everyone), and it moves only energy that is already surplus, at a low transmission charge meant to make short, opportunistic trades worthwhile.

Membership is a matter of public record. FPL, Duke Energy Florida, and Tampa Electric are all listed participants, alongside regional names like Southern Company's utilities, the Tennessee Valley Authority, and Dominion. The platform's rules and roster sit on SEEM's own site, and the filings that created it are in FERC's public docket system, so a reader who wants to check who is trading and under what terms can do so without asking anyone's permission.

II. The honest math on a midday glut

Florida has built a lot of utility-scale solar over the past decade, FPL most of all, and more arrives every year. At midday that fleet can produce more than the local system wants, and without enough batteries to soak it up, the extra power either gets curtailed (dialed back and wasted) or sold to someone who can use it right then. SEEM gives that second option a fast, automated venue instead of a phone call between schedulers.

The catch is timing. The sun that floods Florida with cheap power at 1 p.m. is doing the same to Georgia and Alabama, so the neighbors who might buy often have their own surplus at the exact same moment. Whether a trade clears depends on someone nearby being short of power and on the transmission path having room, and at last public report the volumes moving through SEEM are modest next to the region's total demand. It helps at the margin. It is not a release valve for every spare megawatt.

III. Who sits at the table

Three Florida utilities carry most of the state's load, and all three are in SEEM: FPL, which is the largest and owns the bulk of the solar; Duke Energy Florida, which serves much of the north and the Gulf coast up around Clearwater; and Tampa Electric, the smaller investor-owned utility centered on Hillsborough County. Municipal systems and cooperatives serve other pockets of the state and take part in various ways.

Beyond the state line sit the counterparties that make a trade possible, mainly Southern Company's utilities in Georgia, Alabama, and Mississippi, plus the Tennessee Valley Authority and Duke's Carolinas operations. FERC, the Federal Energy Regulatory Commission, oversees the whole arrangement because the power crosses state lines, which is also why so much of the paper trail is public.

IV. Why it stops short of a real market

Some economists and clean-energy groups argue Florida and its neighbors should go further and form a regional transmission organization, the kind of independent operator that runs PJM in the mid-Atlantic or MISO across the Midwest. Those markets dispatch power plants centrally, run day-ahead and real-time auctions, and pay separately for capacity (a plant's promise to be available when demand peaks). SEEM does none of that. It trades surplus energy in quarter-hour slices and leaves every utility in charge of its own grid.

Whether that changes is genuinely unsettled. FERC let SEEM take effect in 2021 after the commissioners split evenly on whether to approve it, which is a thin mandate, and there is no scheduled path from a light trading platform to a full independent market. It depends on FERC's appetite, on what state regulators in Tallahassee and elsewhere want, and on whether the utilities themselves see a reason to give up control. For now, the honest answer is that Florida has part of a market and no clear timetable for the rest.

V. Worth watching this month

1. FERC's public eLibrary, where SEEM's tariff and membership filings live, is the place to watch for any new participant or rule change, most of which are routine.

2. SEEM's own membership roster is worth a periodic check for a new Florida entrant, such as a municipal utility or cooperative joining, which would signal the platform is still growing.

3. The Florida Public Service Commission's docket list is where utility solar and storm-hardening cases surface, and while those are state matters rather than SEEM business, they shape how much surplus solar Florida will have to sell.

4. The U.S. Energy Information Administration's monthly Florida electricity data is the simplest way to track whether the state's solar share keeps climbing, which is the real driver behind any midday surplus.

5. Any FERC technical conference on Southeast market design, if one is scheduled, would be the rare item here that genuinely matters, because that is where talk of a real regional market would start.

Does SEEM lower my electric bill?

Not in any way you can trace on a statement. Any savings or revenue from a surplus trade flow through a utility's fuel costs and are spread across all customers, so the effect on a single bill is small and indirect.

Is SEEM the same as a power market like PJM or ERCOT?

No. Those are organized markets with an independent operator, central dispatch, and capacity payments. SEEM only matches surplus energy in fifteen-minute windows and leaves each utility running its own system.

Who runs the grid in Florida, then?

Each utility runs its own. Florida has no independent regional grid operator, so FPL, Duke Energy Florida, Tampa Electric, and the others balance supply and demand within their own territories and trade at the edges through SEEM.

Why does Florida have a midday surplus at all?

Because it has built a large amount of solar that peaks at the same time every clear day. When that output runs past what the local system needs and batteries are not available to store it, the extra power has to be sold or curtailed.

Can I see who is trading on SEEM?

Yes. The membership roster is posted on SEEM's website and the filings that created the market are in FERC's public docket system, both open to anyone.