Run the numbers on solar, batteries, and heat pumps before a salesperson does. The Kilowatt Ledger

Terms of Use

Last updated: 15 August 2026

By using kilowattledger.docsanddeadlines.com ("this site"), you agree to the terms below. If you do not agree, please stop using the site.

What this site is

The Kilowatt Ledger publishes worked arithmetic for household energy decisions in the United States — solar arrays, home batteries, and heat pumps — together with the source documents the arithmetic is built from: utility tariff sheets, state regulator decisions, federal tax code sections, and published engineering standards. The point of every page is that you can reproduce the calculation yourself with your own bill in front of you and get the same answer, or find out why you get a different one.

It is a worksheet, not a service, and not a marketplace. This site sells nothing, quotes nothing, and installs nothing. It runs no lead form, no quote tool, and no "get matched with installers" widget. It is not affiliated with, sponsored by, or compensated by any solar installer, equipment manufacturer, lender, utility, or incentive administrator, and it accepts no referral fee, finder's fee, or commission from any of them. The only money involved is display advertising, described below, which is placed automatically and which the author does not sell directly.

No professional advice

Content here is general information, not professional advice.

The author is not a tax adviser, financial adviser, licensed electrician, HVAC contractor, professional engineer, or energy auditor, holds no licence or certification in any of those fields, and offers nothing on this site as tax, financial, investment, engineering, or construction advice. Reading this site, or emailing the author, creates no professional or advisory relationship.

In particular, this site does not:

  • tell you whether to buy a solar array, a battery, or a heat pump, or which product or contractor to choose;
  • calculate what you personally owe or can claim on a tax return, or advise on tax planning of any kind — where a federal credit is discussed, the page quotes the Internal Revenue Code section and the IRS page and stops there;
  • price your specific home, review your specific proposal, or evaluate a lender, lease, or power purchase agreement you have been offered;
  • specify equipment, sizing, wiring, or placement for an actual installation, which is work for a licensed contractor and your local permitting authority.

A payback figure is an estimate built on assumptions about the future — future rates, future production, future fuel prices. Assumptions are not facts. Anything binding needs your own utility, your own tax professional, and a licensed contractor pulling a permit in your own jurisdiction.

Accuracy and currency

Guides are researched against official sources and dated on publication. Even so:

  • Almost everything this site calculates with is scheduled to change. Federal credits expire — the Residential Clean Energy Credit (26 U.S.C. § 25D) and the Energy Efficient Home Improvement Credit (§ 25C) both ended for expenditures after 31 December 2025. Utility tariffs, export compensation rates, and time-of-use windows are revised on utility and regulator schedules, not on this site's schedule. State and utility rebate programmes run out of budget mid-year. Equipment prices, tariff rates on imported components, and installed cost per watt move constantly.
  • A guide reflects the situation at the date shown on it, not necessarily today.
  • Errors happen.

No warranty is given that content is accurate, complete, or current. If you find something wrong, please report it via the contact page — corrections are made promptly.

Limitation of liability

To the fullest extent permitted by law, the site owner is not liable for any loss, cost, delay, or damage arising from your use of, or reliance on, anything published here — including a system that does not pay back as estimated, a contract signed or not signed, an incentive missed or denied, or expenses incurred by following a guide. You use this information at your own risk.

All original text, layout, and images on this site are © 2026 Priya Raghunathan unless stated otherwise.

You may: quote short extracts for commentary, review, or reference, provided you credit the site and link to the original page.

You may not: republish whole articles, scrape or bulk-copy the site, use the content to train machine-learning models, or present material from this site as your own work — in any case without prior written permission.

Requests for permission: kilowattledger@docsanddeadlines.com

Third-party content and links

External links are provided for convenience. The site owner does not control and is not responsible for the content, accuracy, or privacy practices of any external site.

Advertising

This site displays advertising served by third parties, principally Google AdSense. Advertisements are selected automatically and do not constitute an endorsement of any advertised product or service. Appearance of an ad implies no relationship between the advertiser and this site. Solar installers, lenders, and equipment brands may well appear in those ad slots; that placement is bought from Google, says nothing about the product, and never affects what a page here concludes. See the privacy policy for how advertising cookies work.

Acceptable use

You agree not to attempt to disrupt the site, gain unauthorised access to it, scrape it in a way that burdens the server, or use it for any unlawful purpose.

Changes to these terms

These terms may be updated. The "last updated" date above reflects the current version. Continued use of the site after a change constitutes acceptance of the revised terms.

Governing law

These terms are governed by the laws of the Republic of Korea.

Contact

kilowattledger@docsanddeadlines.com