Solar & battery
Solar Installation Capacity Calculator
Works how much an installer can deliver, where permitting rather than labour is the bottleneck.
Result
Install capacity is rarely the real constraint in solar. Permitting queues, utility interconnection approval and inspection scheduling usually cap throughput well below what the crews could physically build, which is why pipeline management matters more than crew count.
Get a Free Business AuditHow the calculation works
Crews times installs per crew per period gives installed capacity in jobs and in kilowatts. The constraint in practice is frequently upstream or downstream of the crews: permitting timelines, utility interconnection approval and inspection scheduling all meter the throughput regardless of how many crews are available.
What moves the number
- Crews and installs per crew per week.
- Permit approval timelines in the jurisdictions served.
- Utility interconnection and inspection scheduling.
- Equipment lead times.
Where this one goes wrong
Adding crews against a permitting bottleneck produces idle crews rather than additional installs, which is an expensive way to discover where the constraint is. Measure the pipeline stage by stage before expanding. Jurisdictions also differ enormously in permitting speed, which means the mix of territories served changes achievable throughput as much as crew count does, and concentrating in faster jurisdictions is a genuine operational lever.
Before you quote
- Measure each pipeline stage before adding crews.
- Track permit and interconnection timelines by jurisdiction.
- Account for equipment lead times in the schedule.
Questions
About this calculator
What limits a solar installer's throughput?
Frequently permitting, interconnection approval and inspection scheduling rather than crew capacity. Adding crews against that bottleneck produces idle crews, which is an expensive way to find out where the constraint actually is.
Does jurisdiction mix affect capacity?
Considerably, since permitting speed varies enormously between authorities. The territories an installer works in change achievable throughput as much as crew count does, which makes territory selection a real operational lever.
How should capacity be measured?
Stage by stage through the pipeline: sold, designed, permitted, installed, inspected, energised. The narrowest stage is the capacity, and measuring only installs completed hides where the work is actually accumulating.
The formula
jobs = usable crew days x crews / days per job
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How to use this calculator
- Install crews. Enter your own figure; the page starts at 2.
- Working days per month. Enter your own figure; the page starts at 21.
- Crew days per job. Enter your own figure; the page starts at 1.5.
- Average system size (kW). Enter your own figure; the page starts at 7.2.
- Days lost to weather (%). Enter your own figure; the page starts at 12%.
- Capacity lost to callbacks and rework (%). Enter your own figure; the page starts at 6%.
The result updates as you type, so you can try a figure, see what it does to jobs per month, and change it back. Nothing you enter is sent anywhere or saved.
A worked example
These are the figures the calculator opens with. Every number in the results column below is produced by the same calculation the page runs, so you can follow it through before putting your own figures in.
What goes in
| Input | Value |
|---|---|
| Install crews | 2 |
| Working days per month | 21 |
| Crew days per job | 1.5 |
| Average system size (kW) | 7.2 |
| Days lost to weather | 12% |
| Capacity lost to callbacks and rework | 6% |
| Revenue per watt | $3.1 |
What comes out
| Result | Value |
|---|---|
| Jobs per month main result | 23.2 |
| Capacity installed | 166.8 |
| Monthly revenue | $516,967 |
| Annual capacity | 2,001.2 |
| Usable crew days per month | 17.4 |
23.2 jobs a month, 166.8 kW, worth about $516,967. Weather and rework take 18 of the calendar before a single panel goes up.
How sensitive the answer is
Holding everything else steady and changing only revenue per watt, this is what happens to jobs per month. It is worth knowing which of your inputs the answer actually hinges on, and which barely move it.
| Revenue per watt ($) | Jobs per month |
|---|---|
| $1.55 | 23.2 |
| $2.33 | 23.2 |
| $3.1 example above | 23.2 |
| $4.65 | 23.2 |
| $6.2 | 23.2 |
Every other input is held at the example value while this one changes, which is not how a real job behaves. Treat it as a guide to which number matters most, not as five separate quotes.
What each figure means
- Install crews
- A number, between 0 and 100, starting at 2.
- Working days per month
- A number, between 0 and 31, starting at 21.
- Crew days per job
- A number, between 0 and 60, starting at 1.5.
- Average system size (kW)
- A number, between 0 and 5000, starting at 7.2.
- Days lost to weather (%)
- A percentage, between 0 and 60, starting at 12%.
- Capacity lost to callbacks and rework (%)
- A percentage, between 0 and 40, starting at 6%.
- Revenue per watt ($)
- A money amount, starting at $3.1.
What the results tell you
| Result | What it is |
|---|---|
| Jobs per month | The headline result. A decimal figure. |
| Capacity installed | A decimal figure. |
| Monthly revenue | A money figure. |
| Annual capacity | A decimal figure. |
| Usable crew days per month | A decimal figure. |
A design still needs a site visit
Output and sizing figures use the assumptions you enter, not measured irradiance, shading or roof orientation at your address. Real production depends on all three, plus inverter behaviour and local interconnection rules.
Estimating is the easy part
The jobs you never hear about cost more than the ones you mis-measure. BDEVY builds the marketing, systems and automation that bring them in.