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Cost per usable watt hour: the only fair price comparison

Last checked November 7, 2026. Researched from manufacturer spec sheets and retailer listings. How we research.
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Short answer

Divide the price by the energy you can actually use. Rated capacity overstates every station by roughly 15 percent, so price per rated watt hour flatters whichever maker rounds hardest. Priced per usable watt hour as complete systems (station, panels it can use, cables, 7 percent Indiana tax), the ranking in our checked research is BLUETTI Apex 300 at $1.18, EcoFlow DELTA Pro 3 at $1.39, and Anker SOLIX F3800 Plus at $1.41, and the fine print under the table matters as much as the order.

The table: big three systems, priced per usable watt hour

Click any column heading to sort. Every figure traces to our checked configuration research from October 2026, rechecked for launch. These are dated research figures, not live quotes; the weekly refresh updates them, and the checked date is part of the data.

Station (system) Rated Wh Usable Wh at 85% System total with tax $ per usable Wh Panels in the system
EcoFlow DELTA Pro 34,0963,482$4,830.96$1.39Four 400W rigid
Anker SOLIX F3800 Plus3,8403,264$4,618.03$1.41Four 400W rigid
BLUETTI Apex 3002,764.82,350$2,765.86$1.18Two 400W rigid (its input cap)

Checked October 2026, rechecked November 7, 2026. System totals include the station, the panels each system can actually connect, required cables, and 7 percent Indiana sales tax. Your state tax and panel choice will change the totals; the method will not change.

Why the ranking flips, and what the metric misses

Priced by the box alone at sale prices, the Apex 300 can look merely cheap and the DELTA Pro 3 merely premium. Priced per usable watt hour as systems, the Apex is the efficiency winner and the other two nearly tie, with the Anker's stronger output stage invisible to the metric entirely. That invisibility is the lesson: cost per usable watt hour is the fairest single price number, and it is still a single number. It says nothing about refill speed (the Apex's 800W ceiling), output (the Anker's 6,000W native split phase), or expansion paths. Use it to reject bad value, then use the head to head to choose among the survivors.

The table grows as our refresh cycle verifies more models. A model joins this table only with a checked system price behind it, never with a scraped one.

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Sources and checking. Capacities and solar input limits come from the Anker, EcoFlow, and BLUETTI product pages. System totals come from our checked October 2026 configuration research including Renogy 400W rigid panel pricing with freight and 7 percent Indiana tax. Figures were checked on November 7, 2026. Prices in this category move weekly, so confirm the current listing before you buy. If you spot an error, tell us at contact@backuppowerguides.com and we will fix it and move the checked date.