Free tools · Nebula sizer
Size an off-grid system.
Tell it your equipment and the backup you need. Get the batteries, panels and cabinets. Free, no sign-up.
Nebula sizer
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Your Nebula
on the battery alone, after a 10% reserve
- Energy per day
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- Solar array
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- Canopy area
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- Recharge from empty, worst month
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Battery modules from your load, the cabinet's own use and the backup days, counting 80% of each module and keeping a 10% reserve; 24 V modules for small sites, 48 V above. Panels sized for twice the daily use in the worst month and a refill from empty within 5 days. Solar outside the modelled markets is estimated from latitude and climate. We confirm every system after a site survey.
Stress test: a dark spell
Drag the slider to see how the battery holds up when the sky gives only a quarter of its usual light.
Each dark day delivers 25% of a normal day's solar energy. Starts from a full battery; the dashed line is the 10% reserve.
Against how the site is powered today
Nebula needs 4 to 8 planned visits a year. Set how often batteries are swapped at your site today.
Sustainability over ten years, against your current site
t CO2e avoided
- Site trips avoided
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- Grid charging avoided
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- Trees growing for ten years
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t CO2e avoided
- Diesel not burned
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- Fuel and service trips avoided
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- Trees growing for ten years
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Questions
About this tool
How is the system sized?
From the daily energy of your equipment, plus the cabinet's own use and losses, against the backup days you choose with no sun, and the solar needed to refill the battery in your country.
What does backup with no sun mean?
The days the site runs on the battery alone, with no sun at all, while a 10% reserve stays untouched. You choose the days; we size the battery modules to them.
How do I size solar and batteries for CCTV at a remote site?
List each device with its watts and the hours it runs a day. The tool turns that into energy per day, then picks battery modules for the days of backup you need and panels to refill them in your worst month.
How much of the battery is used?
Backup counts 80% of each module as usable and keeps a further 10% in reserve for ageing and heat.
Is the tool free?
Yes. Results appear instantly in your browser. Add your email only if you want the report sent to you.
More free tools: Hybrid Power Simulator, Carbon Impact Studio, Marine Operations.