Energy contracts are boring, long, and they survive a change of ownership. That combination makes them among the most reliably skipped documents in a diligence process, and among the more expensive things to discover afterwards.

The problem is not usually a bad rate. It is a structure the buyer did not know they were assuming.

The five clauses worth reading properly

• Change-of-control. Some supply agreements let the supplier reprice or terminate on a change of ownership. Others bind the acquirer to the full remaining term. Both matter, in opposite directions.
• Auto-renewal. Evergreen clauses that roll to a new term unless cancelled in a specific window are common. A deal closing in the wrong month can lock you into another year of a rate you planned to replace.
• Early termination. Exit fees are frequently structured as remaining contract volume at a mark-to-market difference. That is not a fixed number, it moves with the market, and it can be substantial.
• Bandwidth and swing provisions. Fixed contracts often carry penalties for using materially more or less than the estimated volume. If your plan changes production levels, you may be buying a penalty.
• Demand ratchets. A peak set before you owned the site can set a billing floor that follows you for months.

What the seller will not volunteer

Not from bad faith, usually. Energy sits with facilities, facilities does not sit in the deal room, and nobody asked. A request list saying "all utility agreements" gets you the supply contracts and misses the transportation agreements, the demand response enrollments and the interconnection commitments.

Ask specifically. Supply contracts, transportation and delivery agreements, any demand response or curtailment enrollment, any on-site generation or solar power purchase agreement, and the last twenty-four months of interval data for each site.

The interval data is the real prize

Twenty-four months of interval data tells you what a rate sheet cannot: what the load actually does, whether the site is seasonal, whether the peaks are operational or accidental, and whether the historical contract was ever a good fit.

It also gives you a baseline. Without it, any post-close savings claim is unverifiable, which matters if energy reduction is part of the investment thesis.

Portfolio effects are the upside

The bull case in most of these deals is aggregation. Two mid-sized loads bid separately are two mid-sized books. Combined, they are one larger book, and larger books get better pricing. That is a genuine synergy and one of the few that shows up in the first year rather than the third.

The constraint is deregulation. Supplier competition only exists in markets with retail choice, and a site on a municipal utility or in a regulated market has no supply contract to bid out. Map that before you model it.

A practical sequence

• Request the full document set early, not in the final week.
• Pull interval data for every site and establish a real baseline.
• Flag change-of-control and auto-renewal dates against the expected close date.
• Model the combined portfolio as a single bid to size the aggregation upside.
• Price the exit cost of any contract you intend to replace, at current market, not at signing.

None of this is complicated. It is just rarely assigned to anybody, which is why it keeps producing surprises after close.