Home Energy Load Audit
XLSX · 55 KBList your appliances room by room to see how much electricity you use, and when. Includes a 12-month bill history, a meter log to split day and night use, and typical wattages.
The companion tools from The Practical Solar Guide, in chapter order. Spreadsheets and checklists to work out what you use, size the system, compare quotes and keep an eye on it once it's running. Free to download, no sign-up.
Eight chapters on going solar properly, written by an engineer, with a free tool for each one. Read the first two chapters free.
Before anyone quotes you a system, find out what you actually use and what you can cut. It's the cheapest kWh you'll ever save.
List your appliances room by room to see how much electricity you use, and when. Includes a 12-month bill history, a meter log to split day and night use, and typical wattages.
Paste in your load audit, plan your changes (timers, swaps, shifting loads to daytime) and see the energy, money and payback of each before you size any solar.
Where the panels go, which inverter can take them, and how much battery you really need. Check the numbers yourself before you trust a quote.
Walk your roof with a compass app, tape measure and camera: direction, pitch, shading and usable area for each roof face, plus a roof-condition check before panels go on.
Check string lengths against your panel and inverter datasheets for hot and cold days, test start-up surges from motors and compressors, and tick off the features you need.
Work out the energy each job needs, from outage backup to evening use, then check usable capacity and whether the bank can deliver your biggest loads.
Compare quotes like for like, don't pay the final invoice until handover is done, then keep a monthly eye on the system and on your payback.
Put up to three installer quotes side by side: equipment, warranties, compliance and the things a quote doesn't state. A filled-in example is included.
Print it and go through it with your installer on handover day, before you make the final payment.
Copy three numbers from your inverter app once a month and see how they compare with what your system should produce. Also has a maintenance schedule and a fault log.
Enter your quote, tariff and local production for year-by-year savings and break-even, next to the chapter's case study for South Africa, Australia, the UK and the US.
Spreadsheets are .xlsx files: open them in Excel or any app that reads Excel files. Yellow cells are for your inputs; each workbook has a Start Here sheet and a worked example. These tools give estimates to help you plan and ask better questions; they don't replace a site visit by a qualified installer.