About this site

This is published by Nathan Management, a California publisher of single-purpose calculators, run by Andrew Flores. It exists because working out whether a home battery is worth buying turned out to require assembling a tariff, a tax rule, a manufacturer datasheet and an interconnection agreement, and nothing available did that honestly.

What was actually wrong with the alternatives

A home-battery payback page can take one of two shapes that this site avoids. The first asks you for an annual saving and divides your cost by it — which hands the entire question back to the reader and calls the division an answer. The second quotes a national average cost, a national average saving, and produces a payback figure that describes no actual household.

Both share a deeper problem: they cannot return a negative result. A page whose job is to produce a payback number will always produce one, and the cases where storage genuinely does not work simply come out as large numbers of years rather than as the plain answer they deserve.

The choices that follow from that

Derive, do not ask. The tools take facts a household can gather — a quote, a rate plan, an annual consumption figure — and compute the rest. Nothing asks you for the answer.

No number without a stated basis. All 98 registered figures carry a label and a retrieval date. The sourced ones also name their source and keep an evidence record tied to a saved copy of the page they cite; the few labelled assumed are our own values, say so where they are used, and point to the methodology page instead of to an outside source. The build fails if a page cites a figure identifier that is not in the register. It does not check numbers typed straight into a page as illustrations, such as an example quote price, which are labelled as illustrative where they appear; the editorial policy sets out the difference. The methodology page is generated from that register rather than written alongside it.

A missing number beats an invented one. We hold no installed-cost data, so no sourced installed-cost figure appears anywhere on the site and the calculator asks for your quote. Where a page needs a price to show the arithmetic, it uses an example quote and labels it as illustrative. The blank is visible; a fabricated average would not have been.

No is a valid output. Three distinct failure modes are modelled and reported as sentences. Where a rate plan cannot support storage at all, the tool says so instead of quoting a forty-year payback.

How this is paid for

By advertising, if and when it is approved — nothing else. There are no installer referrals, no lead capture, no affiliate links to equipment, and no relationship with any manufacturer whose specifications appear here. The editorial policy sets out what would have to change for that to stop being true and how it would be disclosed.

The practical consequence is that the site has no reason to talk you into a purchase. Several pages here argue against buying a battery, which would be an odd thing to publish if the business model depended on selling one.

Scope, and what this is not

This covers grid-connected residential storage in the United States. It is not off-grid system design, not commercial or utility-scale storage, and not electric vehicle bidirectional charging, all of which are different problems with different arithmetic.

It is also not financial advice, tax advice, or an engineering assessment of your electrical service. Those require a licensed professional looking at your specific circumstances, and this site is a way to arrive at that conversation with better questions.

Corrections are welcome and acted on. If a figure has drifted from its source or an engine gets something wrong, the contact page reaches a human.