Every product on ShopForTerra carries a 1-to-10 eco-score and one or more eco-tags. The score is meant to be a quick 'is this worth your attention?' signal; the tags are meant to let you check the working. This article explains how both are produced so you can see the reasoning behind any rating, not just the number.
Why publish the methodology
When ratings are published as a single opaque number, the rater can be quietly biased by commercial pressure — a brand that pays more could get a bump. Publishing the rubric makes that harder. If you understand what each factor measures and how it's weighted, you can sanity-check the score against your own priorities, and you can tell when something looks off.
The eco-score is not a third-party certification. It's an editorial rating by a small team. We're upfront about that. The methodology exists so the editorial judgment is reproducible, not so we can pretend it's an audit.
The four factors
The score is a weighted blend of four factors.
Energy savings (40 percent)
The largest weight goes to whether the product genuinely reduces household energy use, relative to the typical product it replaces. A solar panel that produces kWh displacing grid electricity scores here; an air conditioner that uses 30 percent less electricity than the model it replaces scores here; an insulation product with a higher R-value per inch scores here.
We look at published efficiency specs (SEER, EER, R-value per inch, panel efficiency percentage, battery round-trip efficiency) and at the manufacturer's published lifetime yield or savings estimates. Where claims depend on assumptions (sun hours, climate zone, usage pattern), we mark them as such.
Durability (25 percent)
Long-lived products amortize their embodied energy over more years of use. A battery with 4,000 cycles at 100 percent depth of discharge outranks one with 500 cycles. A solar panel with a 25-year linear warranty outranks one with a 10-year limited warranty. A window AC rated for 10+ years of use outranks a throwaway unit that won't survive three summers.
Warranty documents and published cycle life are the primary inputs; in their absence, brand track record and parts availability stand in.
Material impact (20 percent)
This factor considers what the product is made of, how much of it is recycled content, and what happens at end of life. Recyclable aluminum framing and steel-cased batteries score higher than un-recyclable plastic-only housing. Modularity and repairability count — a battery whose cells can be replaced without replacing the whole unit outscores a sealed one.
This is the factor where we lean most on eco-tags: a product tagged 'Modular' or 'Repairable' is showing its work for this category.
Brand behavior (15 percent)
The smallest weight goes to company-level signals: warranty terms, repair availability, parts support, take-back programs, and whether the brand publishes its own sustainability reporting. A smaller weight because company behavior is harder to verify than product specs, but it still matters when the spec sheets are close.
How the tags work
Eco-tags are short, evidence-yielding labels that show why a score is what it is. We use them rather than long-form notes because they're scannable — you can see at a glance that a portable power station is tagged 'LiFePO4,' 'Off-grid Ready,' and 'Plug-and-Play Solar' and understand the reasoning.
The full set of tags is open-ended; we add new ones as products warrant. A few examples:
- 'Plug-and-Play Solar' — the product supports direct plug-in solar charging without a separate charge controller
- 'Off-grid Ready' — designed to operate without grid infrastructure
- 'Energy Efficiency' — meaningfully more efficient than the typical product in its category
- 'Modular' / 'Repairable' — components can be replaced or extended individually
- 'DIY Friendly' — practical for a homeowner to install without specialist labor
How to use the score
The score is a starting point, not a verdict. Two products with similar scores can be very different fits depending on your home, your climate, and your goals. Use the tags to align what you care about (repairability, off-grid capability, raw efficiency) with what the product actually delivers.
When you've narrowed it down, the calculators on the home page can put real numbers on whether the upgrade makes sense — and the rest of the Learn library walks through the buying process for each category.