Solar Load & Battery Planner
Inventory off-grid electrical loads and estimate daily energy, panel quantity and nominal battery capacity from your own assumptions.
- 1List your devices
- 2Read the answer as you type
- 3Download or print it
Loading the worked example…
Assumptions
Results update as you type. Example figures are illustrative.
Your working data
Edit cells directly or import a CSV. Download “Input CSV” for the required column names. Up to 200 rows; scroll the table sideways for additional fields.
Detailed analysis
Exports include all results, regardless of the search filter. The HTML report includes assumptions and source data; use your browser’s Print command for PDF.
Chart shows the first 20 rows; negative values use a warm color. Click table headers to sort.
Compare up to four scenarios
Capture the current inputs, change assumptions and capture again. Scenarios are included in downloaded projects.
What this model includes
Energy-budget estimate only, not an electrical design. Assumes all running loads can coincide and only one device starts at a time. No weather, shading, wiring or battery chemistry model.
Import and save safely
CSV imports use your current assumptions. Project files restore assumptions, rows and saved scenarios. No automatic saving: download a project before closing this page. Imports are limited to 10 MiB and 200 rows. Calculations run in your browser; the site’s advertising and analytics follow its privacy policy.
Using Solar Load & Battery Planner
Inventory off-grid electrical loads and estimate daily energy, panel quantity and nominal battery capacity from your own assumptions.
- Set sun hours, efficiencies, panel watts and backup days.
- List each device with quantity, watts, hours a day and starting watts.
- Read the panels, battery and inverter beside your table, then download them.
Example
The worked example includes Lights, Fridge, Laptop. Change the first peak-sun hours/day setting and compare the result with a saved baseline.
Questions & answers
What does Solar Load & Battery Planner calculate?
Inventory off-grid electrical loads and estimate daily energy, panel quantity and nominal battery capacity from your own assumptions.
What are the important limitations?
Energy-budget estimate only, not an electrical design. Assumes all running loads can coincide and only one device starts at a time. No weather, shading, wiring or battery chemistry model.
Can I continue my work later?
Yes. Save a project JSON file and reopen it with Import CSV / project. It contains the working data, assumptions and up to four scenarios. Nothing is saved automatically.
What CSV columns do I need?
device, qty, watts, hours, surge. Download Input CSV for a compatible example. CSV imports keep your current assumptions.
Are these example figures current industry benchmarks?
No. They are illustrative values to demonstrate the model. Replace them with figures appropriate to your situation.
Related tools
A useful next step for your task.
Everyday CalculatorsAppliance Energy AuditBuild a whole-home appliance inventory, compare active and standby consumption and identify the biggest annual energy costs.
Everyday CalculatorsBattery Runtime EstimatorEstimate ideal runtime from capacity, voltage, load and supplied usable fraction.
Everyday CalculatorsElectricity Cost CalculatorEstimate appliance electricity use and running cost from wattage, usage time and the energy rate you enter.
Everyday Calculators2026 Tax Refund EstimatorEstimate your 2026 federal income tax refund or balance due with the new IRS brackets, standard deduction, tips, overtime, car-loan and senior…
Help improve this tool
Report a problem or suggest an improvement
Describe the issue without pasting private tool input. Feedback goes to our admin inbox.