The problem with a single asset
Contract with one solar farm and you have bought a shape: strong at midday, nothing at night, seasonal to the point of embarrassment in December. Contract with one wind farm and you have bought volatility, generous over a winter week and absent over a still fortnight.
Neither matches an industrial load, which is broadly flat and does not care what the weather is doing. The mismatch has a cost, and somebody pays it, either as top-up power bought at short notice or as generation spilled at whatever the market offers.
What a hybrid does
A hybrid PPA contracts for a portfolio rather than an asset. Solar and wind are complementary: solar peaks in the middle of the day and in summer, while wind is often strongest at night and in winter, so combining them flattens the profile before anything clever happens. Add storage and you can move surplus generation from the middle of the day into the evening peak.
The result is a contract that covers more of your hours with less top-up, which is worth more than the sum of the individual assets even where the blended unit price looks higher than the cheapest one on the table.
What changes in the contract
Hybrids are more complicated to negotiate, and the complications are where the value sits.
Volume commitment. A portfolio can commit to a firmer volume than any of its components. That may be pay as forecast in place of pay as produced, or a partial baseload obligation with the seller shaping the balance.
Asset substitution. Can the seller swap an asset in or out during the term? You want traceability to named assets for reporting purposes, and the seller wants flexibility to optimise. This gets negotiated.
Storage revenue stacking. A battery serving your contract is not serving the balancing mechanism at the same time. Who captures that opportunity cost, and how it is priced, is a real negotiation and frequently a badly handled one.
Certificates. Multiple assets mean multiple certificate streams, and if the storage is charging from the grid at any point the clean claim on those units needs care.
When it is worth it
From around 20 GWh a year, and particularly where you are chasing hourly coverage and not an annual percentage. Below that the added complexity rarely pays for itself, and either a single well negotiated contract or matched supply through a supplier partner is the better answer.