Grid-scale storage pencils on cost per megawatt-hour, and Tesla has said as much in its own words. An earlier Form 10-K, surfaced through EdgarBeast, attributes a gain in energy gross margin to “an improvement in our Megapack gross margin from lower average cost per MWh and a higher proportion of Megapack.” Two levers, both on the cost-and-mix side of the ledger.
This is the more encouraging counterpart to the price-down story in the latest 10-K. If average selling price is falling (as the FY2025 filing states) but cost per MWh is also falling, then storage margin depends on the race between the two curves. The earlier disclosure is evidence that, in at least one period, the cost curve won.
Does it pencil? The mechanism is sound. Megapack is a standardized, factory-built product, and standardized products ride a manufacturing learning curve — each doubling of volume tends to pull unit cost down. A higher Megapack mix (versus older or lower-margin products) compounds that, because the better-margin product carries more of the revenue. That is real, durable margin, not a one-off.
The caveat is that cost-per-MWh improvement has to keep outrunning price erosion in a competitive procurement market. A learning curve that flattens while bidding stays aggressive would compress the very margin this disclosure celebrates. The filing confirms the favorable period; it does not guarantee the relationship holds every quarter.
We count, we don't advise. The takeaway: Tesla's own filings locate storage profitability in cost per MWh and product mix, which is exactly where a durable grid-storage business should earn its margin — so watch cost per MWh against ASP, not ASP alone. Language from Tesla's 10-K at sec.gov, indexed by EdgarBeast.