Solar estimating software for design, BOS and the electrical scope
Solar estimating software lays out modules on a roof or site, sizes the system, and turns the design into a bill of materials and a price: modules, racking, inverters, combiners, wire, conduit and labor. Residential and commercial installers commonly use design and proposal platforms such as Aurora, HelioScope and OpenSolar123. On commercial projects with engineered plan sets, electrical contractors also take off the balance of system from the PV and electrical sheets with plan takeoff tools.
What a solar takeoff measures
| Item | Unit | What to watch |
|---|---|---|
| Modules | EA (and kW DC) | Count from the array layout. The module count also drives racking, attachments and DC wiring. |
| Racking and attachments | LF of rail / EA | Rails, clamps and roof attachments on pitched roofs; ballast and blocks on flat roofs; piles or posts on ground mounts. |
| Inverters and power electronics | EA | String inverters, central inverters, microinverters or optimizers, with mounting and communication gear. |
| Combiners, disconnects and rapid shutdown | EA | Usually shown on the PV electrical sheets and the single-line diagram. Check both. |
| DC and AC wire | LF by size | Home runs from arrays to inverters and from inverters to the point of interconnection, including voltage drop sizing. |
| Conduit and pathways | LF by size | Roof runs, wall penetrations and underground runs to ground mounts or the service. |
| Interconnection and service work | EA / allowance | Breakers, switchgear modifications, meters and utility requirements. Often the least defined part of the bid. |
| Storage | EA (and kWh) | Batteries, gateways and their electrical connections when the project includes them. |
How a solar estimate is built
- Confirm the scope: design-build or engineered drawings, roof or ground, storage, interconnection and who handles utility and permit work.
- Model the site or roof, or read the array layout from the PV plans, and fix the module count and system size.
- Select inverters and stringing, then size combiners, disconnects and rapid shutdown equipment.
- Take off racking, attachments or ballast from the layout and the structural details.
- Measure DC and AC wire and conduit from arrays to inverters to the point of interconnection.
- Add interconnection, service upgrades, monitoring, permits, engineering, equipment rental and commissioning.
- Price material, labor and margin, and for sales-led work produce a proposal with production estimates and financing.
What to look for in solar software
Layout and production modeling
Site or roof modeling, shading and production estimates. Essential for sales-led residential and commercial work where the proposal sells the system.
Bill of materials from the design
Modules, racking, inverters and electrical components generated from the layout so the estimate follows the design changes.
Electrical balance of system
Wire, conduit, combiners, disconnects and interconnection, either generated or taken off from the plan set. This is where design tools and estimating tools meet.
Proposals and pricing methods
Custom pricing, adders, incentives and financing for sales-driven work; clean scope and exclusions for bid-driven commercial work.
Software solar estimators use
| Tool | What it does for solar | Price |
|---|---|---|
| Aurora Aurora Solar | Solar sales and design: 3D roof modeling, automated panel placement and stringing, performance simulation, AHJ and component databases, and proposals with custom pricing methods, adders and incentives.1 | Basic $159 and Premium $259 per user/mo, billed monthly (50 projects/mo); Enterprise custom |
| HelioScope Aurora (HelioScope) | Commercial solar-plus-storage design and simulation for rooftop, carport and ground mount, with CAD export and single-line diagrams. Basic covers designs up to 1.25 MW DC, Pro up to 5 MW.2 | Basic $159 and Pro $259 per license/mo (10 projects/mo); Enterprise custom |
| OpenSolar OpenSolar | Design, sales and project software for solar professionals, funded by partners (manufacturers, finance companies, distributors) so installers do not pay for it.3 | Free for solar professionals |
| STACK STACK Construction Technologies | Plan takeoff and estimating for engineered PV sets: count modules and equipment, measure conduit and wire runs, and price with items and assemblies.4 | Free plan; Premium $299 and Pro $349 per user/mo, billed annually |
| Bluebeam Revu Bluebeam | PDF measurement and counts for reviewing PV and electrical sheets and measuring home runs before pricing in a spreadsheet.5 | Basics $260, Core $330, Complete $440, Max $590 per user/yr |
As described on each vendor's own pages, checked November 3, 2026. Prices change; check with the vendor.
For tools that cover every trade on one plan set, see the construction takeoff software and construction estimating software guides.
Design platforms vs estimating the electrical scope
Solar software splits along how the work is sold. Residential and small commercial installers sell the system, so they need site modeling, production estimates and a proposal the customer signs; Aurora, HelioScope and OpenSolar are built for that123. On larger commercial projects the system is engineered, a plan set goes out to bid, and the electrical contractor's job is to price what is drawn. There the work looks like any electrical takeoff: count equipment from the PV and electrical sheets, measure wire and conduit, and add interconnection and labor.
The National Electrical Code (NFPA 70) governs the electrical side of PV installations. NFPA lists 2026 as the current edition and notes the NEC is enforced in all 50 states6, but local adoption of a given edition varies, so check which one applies before you price rapid shutdown, labeling and interconnection details.
Rapid shutdown, the 120% rule and the PV electrical takeoff
On a commercial PV job most of the electrical contractor's labor sits away from the modules. NEC 690.12 requires PV system circuits installed on or in buildings to include a rapid shutdown function to reduce shock hazard for emergency responders7, which brings module-level electronics or shutdown devices, an initiation switch and labels into the bid. Count those from the PV electrical sheets and the single-line diagram, then carry the DC home runs and their conduit fill the same way you would any feeder.
Interconnection decides how much service work there is. For a load-side connection, the 120% rule in NEC 705.12(B) caps the combined current on a panelboard busbar from the utility and the PV system at 120% of the busbar rating when the backfed breaker sits at the opposite end from the main8. A 200 A busbar with a 200 A main leaves 40 A, which after the 125% factor allows about 32 A of continuous inverter output8. Bigger systems usually mean a supply-side connection, a new panel or switchgear work, and if the service is also being upgraded, check it against the load calculation for the building.
Ground mounts and carports add trenching from the array to the inverter pad or the service, which may share a trench with other utilities in the earthwork takeoff. With an engineered set, commercial PV is priced like any other job in commercial electrical estimating software: equipment counted, wire and conduit measured, labor applied.
Where solar takeoffs go wrong
- Estimating from a module count alone and missing the balance of system, which carries much of the electrical labor.
- Underestimating wire and conduit on commercial roofs and ground mounts, where home runs are long.
- Leaving interconnection and service work as a vague allowance when the utility requirements are known.
- Pricing racking for the wrong roof type or wind and snow conditions.
- Not reconciling the PV sheets with the single-line diagram, so a disconnect or combiner shown on one is missing from the other.
Trades that bid the same job
A solar bid rarely stands alone. The trades next to it on the schedule read the same drawings and often share scope lines, so it pays to know how they take off too: roofing estimating software and low voltage estimating software.
Where AmpCount fits
AmpCount does not design arrays, model production or price solar systems. On commercial projects where the electrical contractor bids from a vector PDF plan set, it counts the electrical devices drawn as legend symbols on those sheets, such as disconnects, receptacles, panels and fixtures on the same job, and exports the counts to Excel or CSV. Module layout, racking, stringing and wire lengths stay in your solar design tool or takeoff tool.
Questions
What is the best solar estimating software?
For sales-led residential and small commercial work, design and proposal platforms like Aurora or OpenSolar. For commercial solar-plus-storage design and simulation, HelioScope2. For engineered commercial bids, a plan takeoff tool plus your electrical estimating process for the balance of system.
Is there free solar design software?
OpenSolar says its software is free for solar professionals because partners such as manufacturers, distributors and finance companies fund the platform3.
How much does Aurora cost?
Aurora lists Basic at $159 and Premium at $259 per user per month billed monthly, each with 50 projects a month, and custom Enterprise pricing1. Annual plans are discounted1.
What does a commercial solar estimate include besides modules?
Racking or ballast, inverters, combiners, disconnects, rapid shutdown, DC and AC wire, conduit, interconnection and service work, monitoring, permits, engineering and commissioning. The balance of system is where most electrical labor sits.
Guides and tools for any trade
Sources
- Aurora Solar pricing
- HelioScope pricing (an Aurora company)
- OpenSolar, Why is OpenSolar free?
- STACK takeoff and estimate pricing
- Bluebeam pricing
- NFPA 70, National Electrical Code (document page)
- ElectricalLicenseRenewal.com, NEC 690.12 Rapid Shutdown of PV Systems on Buildings
- GreenLancer, The 120% Rule for Solar: NEC 705.12 Calculator and Guide
Product names are trademarks of their owners. AmpCount is not affiliated with any vendor on this page.