The spec sheets, side by side

Why this database exists

Off-grid equipment is sold with the numbers that flatter it. Battery listings lead with amp hours rather than usable energy, inverters with peak watts rather than continuous, generators with runtime at a load fraction nobody states, and panels with laboratory output that no roof reproduces. None of that is dishonest exactly, and all of it makes two products impossible to compare without transcribing both datasheets onto a common set of columns.

That transcription is what this section is. Each category is normalized onto the same fields, each row records where its figures came from and how confident we are in them, and each product has a page that works its own numbers through for an off-grid build: what a battery can really deliver and how many you would need, how many panels of a given model fit on a controller before a cold morning destroys it, what an inverter costs you in idle draw every day of the year, how many kilowatt hours a generator returns per gallon.

How to compare properly

Three habits do most of the work. The first is to compare on the normalized ratio rather than the sticker price: dollars per kilowatt-hour, per watt, or per amp, because those are the figures that survive differences in size. The second is to check the specification that constrains your particular design before looking at price at all, since a cheaper unit that cannot deliver the current your inverter needs is not cheaper, it is irrelevant.

The third is to read the test conditions. A cycle life quoted at 80 percent depth of discharge is not comparable with one quoted at 100 percent. A continuous rating at 25 degrees Celsius is not what you get in a hot mechanical room. A runtime at quarter load is not a runtime at half load. Where a datasheet gives a number without its conditions, treat it as marketing until you find them.

Where the numbers come from

Figures are transcribed from manufacturer datasheets or primary retailer specification pages, dated, and flagged: verified means read from the manufacturer's own sheet, partial means some fields came from a retailer page or are missing, and generic means the value is class-typical rather than model-specific. Prices are list or observed retail at the date recorded and move constantly, which is why they are here for the ratio rather than for the last dollar.

The whole set is published as CSV and JSON on the open data page under a permissive license, because a table you cannot take away with you is not much of a reference. The price index tracks market ranges over time, the methodology page explains how the research is done, and corrections are logged publicly rather than edited away.

Reading a datasheet without being misled

Manufacturers rarely lie on a datasheet. They choose which figure to lead with, and which conditions to omit, and between those two choices a great deal of comparison becomes impossible unless you know what to look for.

The first question to ask of any figure is: measured under what conditions? Temperature, load fraction, depth of discharge, and distance all change results substantially, and all are routinely left off marketing pages while appearing in the full sheet. The second is: continuous or peak? Inverters, batteries, and generators all publish both, and the peak figure is the one that appears in advertising. The third is: nameplate or usable? Battery capacity and panel output are both quoted at conditions you will not reproduce.

The fourth is about what a warranty actually promises. A product warranty and a performance warranty are different terms of different lengths, and both depend on a company still existing to honor them. Off grid, how a claim is handled matters more than how long the term is: who pays freight on something heavy, whether a replacement ships before the failed unit goes back, and whether an owner installation voids anything.

Where these tables record a figure that its manufacturer published without conditions, it is recorded as published and flagged rather than quietly normalized, because inventing the missing conditions would make the table look tidier and be worth less.

Where to go from a spec table

A specification only means something inside a design. The system planner sizes array, controller, battery, and inverter against each other from your own load list and location, which is the order these decisions actually come in. Lesson four covers building that load list, lesson five the battery and inverter decision, and lesson six the wiring and protection that keep any of it safe.

What is deliberately not in here

There are no star ratings, no editor's picks inside the tables, and no scores. A score is an opinion with a number painted on it, and the opinion usually belongs to whoever is selling. What is here instead is the manufacturer's own figures, normalized, dated, and sourced, plus arithmetic that turns them into something usable. Where this site does have an opinion about what to buy, it lives on the gear page, separately, with the commercial relationships disclosed.

There is also no attempt to list everything. The tables cover the equipment people building off-grid systems are actually choosing between, and they grow when readers ask for something that is missing. A comprehensive catalog of every product ever sold would be less useful, not more, and impossible to keep honest.

How the categories relate

Read across the tables rather than down one. A battery's discharge rating caps the inverter it can feed; the inverter's charger rating sets the generator that suits it; the controller's input ceiling caps the panel string; the panel's cold voltage is what tests that ceiling; the pump's startup draw is what tests the inverter surge. Nearly every expensive mismatch in an off-grid build happens at one of those boundaries.

Each product page names the nearest alternatives in its own table and points at the specific figures in the neighboring tables that constrain it, which is the fastest way to check a shortlist for the mismatch you have not thought of yet.

Confidence flags, and why they are on every row

Each row carries one of three flags. Verified means the figures were read from the manufacturer's own datasheet. Partial means some fields came from a primary retailer specification page, or that fields are missing because the manufacturer does not publish them. Generic means a value is class-typical rather than model-specific, which happens most often with figures manufacturers rarely publish, such as idle consumption or startup surge.

Showing that distinction is more useful than hiding it. A table where every cell looks equally authoritative invites decisions that the underlying evidence does not support, and the fields most often missing are frequently the ones that matter most to an off-grid design. Where a figure is absent, it is left absent rather than filled with an estimate that would be indistinguishable from a measurement a week later.

The same principle runs through the rest of this site: the laws pages mark a rule as unclear rather than guessing, and the calculators publish their formulas and constants. A reference is only worth using if you can tell how much weight each part of it will bear.

Using the data elsewhere

These tables are published as CSV and JSON on the open data page under a permissive license, with the same fields, the same confidence flags, and the same dates as the pages here. Take them, put them in a spreadsheet, and sort them however your own design needs, because a reference you cannot export is a reference you have to keep coming back to on somebody else's terms.

The same numbers feed the calculators on this site, so a figure you see in a table is the figure the arithmetic uses. The battery calculator, the solar calculator, the wire gauge calculator, and the generator calculator all show their working for the same reason: a result you cannot check is a result you should not act on.

If you publish or cite anything from here, a link back is appreciated and the date matters, since specifications and prices both move. If you find a figure that no longer matches its source, tell us; corrections are logged publicly with the date they were made.

For what to buy rather than what exists, the gear page lists what this site actually vouches for and says plainly where it earns a commission. For what things cost this month, the price index. For the parts worth keeping on a shelf before something fails, the spares reference.