Welcome to SolarPlan Pro
SolarPlan Pro is a professional solar panel design tool that helps you plan rooftop installations from start to finish. In 5 simple steps you define your panels, location, roof layout, electrical configuration, and financial parameters — then the app calculates everything: panel placement, wiring, energy production, electrical compliance, and financial returns.
The app works entirely in your browser. No installation needed. You can use it anonymously for quick designs, or sign in to save projects to the cloud and collaborate with your team.
🗺 Quick Workflow
- Choose panels — pick from 70+ verified panel presets or enter custom specs
- Set location — city, sun hours, tilt, azimuth, shading
- Define roof sections — add one or more sections, choose shape, mirror/reposition copies, set exclusion zones
- Configure electrical — inverter, connection mode, strings, battery (optional)
- Enter financials — costs, tariffs, grants, analysis period
- Click Calculate — review results across 7 output tabs
- Export — PDF report, permit package, CSV, PNG, or save the project
Recent Improvements
The March 2026 release plus the latest follow-up updates added deeper equipment coverage, smarter multi-roof layout tools, and stronger validation across proposals, electrical design, and storage modeling.
- Catalog expansion — 70 panels, 99 inverters, and 33 batteries are now built in, including Deye 60/70/75/80 kW hybrids plus larger Jinko and Trina commercial modules.
- Local financial presets — Bulgaria, Romania, Greece, Croatia, Serbia, Germany, and more ship with ready-to-use tariffs, VAT, and subsidy defaults.
- Battery dispatch modeling — residential, daytime, flat, and industrial load profiles now feed self-sufficiency, export, savings, and backup calculations.
- Shareable client proposals — generate branded proposal links that clients can review and accept from their phone.
- Wizard + manual wiring — the project wizard can prefill panel count, inverter, and stringing, while live compliance checks validate voltage and current as you type.
- Two PDF tracks — use proposal PDFs for sales and permit PDFs for technical/authority packs.
- Advanced roof handling — hip, flat/shed, and polygon roofs are joined by section X/Y placement, mirror X/Y tools, and copy-first workflows for stacked roof faces.
- Smarter multi-section systems — shared inverter planning, combiner-aware MPPT checks, live PVGIS data, panel drag, and version history are all built into the latest app flow.
Account & Plans
You can use SolarPlan Pro without an account for basic designs. Sign in to unlock cloud saves, team collaboration, and advanced features.
🔑 Signing Up
- Click Start Free Trial in the header
- Enter your name, email, and password — or click Continue with Google
- You get a 14-day free trial with all Pro features unlocked
📋 Plan Comparison
| Feature | Free | Trial / Pro | Business |
|---|---|---|---|
| Projects | 3 | 10 | Unlimited |
| Cloud Save | — | ✓ | ✓ |
| Connection Modes | Series, Parallel | All 4 | All 4 |
| Roof Shapes | Rectangle | All 7 | All 7 |
| Satellite Overlay | — | ✓ | ✓ |
| Permit PDF | — | ✓ | ✓ |
| Power Optimizer | — | ✓ | ✓ |
| Team Members | — | 5 | Unlimited |
| Watermark | Always | Toggle | None |
Step 1: Panel Specs
Choose your solar panels
The Panel Specs section is the first accordion in the sidebar. Here you select the solar panels for your design.
🔍 Using Presets
- Filter by brand — click brand buttons (LONGi, JA Solar, JINKO, etc.) to narrow the list
- Filter by wattage — use the power range buttons (400-430W, 430-460W, etc.)
- Search — type in the search box to find a specific model
- Click a panel card — all specs (dimensions, Voc, Isc, Vmp, Imp, efficiency) auto-fill
✏️ Custom Panels
Click the + Add Custom card to enter your own panel specs. You can also manually edit any field after selecting a preset.
Step 2: Location & Solar
Set your site parameters
📍 Location
- City — start typing to search 100+ cities. Selecting a city auto-fills sun hours via PVGIS.
- Peak Sun Hours — annual average daily equivalent sun hours (auto-filled by PVGIS or enter manually)
- Tilt — panel tilt angle in degrees (0 = flat, 90 = vertical). Optimal is roughly your latitude.
- Azimuth — panel facing direction (180 = South, 90 = East, 270 = West)
🌤 Shading
- Shading % — estimated annual shading loss (0% = no shade, 50% = heavily shaded)
- Shading simulation — use the time-of-day slider and month dropdown to visualize shadow patterns on the canvas
🏗 Roof Type
- Pitched / Flush — panels mounted flat on the roof surface
- Flat / Racked — panels on tilt racks. The app auto-calculates row spacing to avoid inter-row shading based on latitude.
🌡 Temperature
Enter your site's min and max temperatures. These are used for temperature-corrected voltage calculations (cold = higher Voc, hot = lower Vmp) to validate your string sizing.
Step 3: Roof Sections
Define your roof areas
➕ Adding Sections
- Enter a section name (e.g. "South Roof", "East Wing")
- Pick a color to distinguish sections on the canvas
- Set panel gap (spacing between panels, default 2 cm)
- Choose edge margin — distance from roof edge (5/10/15/20 cm)
- Click Add — a new section tab appears above the canvas
You can add multiple sections for complex roofs. Each section has its own shape, dimensions, orientation, color, and independent canvas position.
📐 Roof Shapes
- Rectangle — standard rectangular area (width × height) FREE
- Triangle — triangular roof face (base width × height) PRO
- Trapezoid — trapezoidal shape (base width, top width, height) PRO
- L-Shape — L-shaped roof (two connected rectangles) PRO
- Hip Roof — 4-face roof with per-face activation and yield analysis PRO
- Flat / Shed — industrial roof mode with row spacing and clamp mounting support PRO
- Polygon — freeform multi-point roof outlines for irregular buildings PRO
↔ Reposition & Mirror Sections
- Use the X and Y fields to place each roof section exactly where it belongs on the canvas.
- Copy an existing section, choose a reference section, then use Move for quick alignment above, below, left, or right.
- Use Mirror X and Mirror Y to flip a copied roof around its reference and stack matching roof faces.
- Negative coordinates are supported, so upper and side roof faces can sit outside the original origin and still export correctly.
🔄 Orientation
- Auto (recommended) — the app tests both portrait and landscape and picks whichever fits more panels
- Portrait — panels standing upright (narrower, taller)
- Landscape — panels lying flat (wider, shorter)
🎯 Target Panel Count
Leave empty for maximum fit. Enter a number to limit how many panels are placed (useful when you need a specific system size).
🚫 Exclusion Zones
Mark areas where panels cannot be placed (chimneys, skylights, vents, HVAC units):
- Enter X, Y position and Width, Height in centimeters, or
- Click Draw Zone and drag directly on the canvas to draw an exclusion rectangle
- Press Esc to cancel drawing mode
Step 4: Electrical Configuration
Inverter, strings, battery
🔌 Inverter Selection
- Use brand filters (Huawei, Deye, SolaX, etc.) to narrow the list
- Select a model from the preset dropdown — all specs auto-fill
- Or manually enter: Max DC Voltage, MPPT range, Max Input Current
The built-in equipment database now spans residential to utility-scale systems, including larger Deye hybrids, expanded BYD and Deye battery stacks, and higher-power commercial modules.
🔗 Connection Modes
| Mode | Description | Best For |
|---|---|---|
| Series | All panels in strings, each string to one MPPT input | Most residential installs |
| Parallel | All panels in parallel, higher current | Low-voltage systems |
| Mixed | Multiple strings, grouped into MPPT channels | Large commercial |
| Micro | Each panel has its own microinverter, AC-coupled | Shaded or complex roofs |
⚡ String Configuration
In Series or Mixed mode, set the number of strings and MPPT inputs. Click Auto-Config to have the app calculate the optimal number of strings based on your inverter's MPPT voltage range and panel Vmp. Compliance also understands combiner-box paralleling, so extra strings can share MPPT inputs when current limits allow.
🔋 Battery Storage (Optional)
- Check Include Battery to reveal battery fields
- Use brand filters and preset dropdown to select a battery (Tesla Powerwall, BYD, Huawei LUNA, Pylontech, etc.)
- Or enter custom: capacity (kWh), depth of discharge (%), power (kW), cost (€)
- Set Essential Load (kW) — the power draw during backup. The app calculates backup hours.
📡 Microinverters
When Micro mode is selected, a microinverter section appears with brand filters (Enphase, APsystems, Hoymiles) and preset models. The app validates panel-to-microinverter wattage compatibility.
⚙️ Power Optimizer PRO
Toggle ON to add per-panel or per-string power optimizers (SolarEdge, Tigo, Huawei). Optimizers modify string voltage limits and add to the total system cost.
🔌 Cable Sizing
Select cable cross-section (2.5 / 4 / 6 / 10 / 16 mm²) and enter average cable run length. The Electrical tab will show voltage drop calculations and compliance status.
Step 5: Financial Parameters
Costs, tariffs, and analysis
Click the Financial section header to expand it. All fields have sensible defaults.
- Panel Cost — cost per watt-peak (€/Wp), e.g. 0.45
- Installation Cost — fixed installation fee (€)
- Grant / Incentive — subsidy amount to subtract (€)
- Annual Consumption — your yearly electricity use (kWh)
- Electricity Tariff — price you pay per kWh (€)
- Feed-in Rate — price received for exported surplus (€/kWh)
- Tariff Rise — expected annual increase in electricity price (%)
- Analysis Period — how many years to model (default 25)
Calculate & Review
Once all 5 steps are configured, click the blue Calculate Layout button at the bottom of the sidebar. The app will:
- Place panels optimally in each roof section
- Calculate string wiring and electrical parameters
- Compute energy production with shading, losses, and degradation
- Run financial analysis over the full analysis period
- Generate the system diagram
- Run electrical validation checks
The status bar at the bottom shows: panel count, system kWp, string configuration. If there are electrical warnings, a validation badge appears in the sidebar.
Output Tabs
After calculation, 7 tabs appear above the main area. Click any tab to view its content.
📐 Layout
Interactive canvas showing panel placement, wiring, rails, mounting points, dimensions. Use toolbar toggles to show/hide layers. Pan with click-drag, zoom with scroll wheel.
📊 Results
Summary cards showing system size (kWp), annual production (kWh), CO2 offset, demand coverage, investment, savings, payback, and net profit. Plus a monthly production bar chart.
⚡ Electrical
Detailed string configuration, voltage/current specs, MPPT compliance, cable sizing with voltage drop table, and any electrical warnings.
💰 Financial
Cost breakdown, LCOE, payback period, ROI, cumulative return chart, and annual savings projection over the analysis period.
⚡ Production
Detailed yield analysis: specific yield (kWh/kWp), performance ratio, capacity factor, monthly breakdown, daily generation curve, self-consumption donut chart, and degradation projection.
🔧 System Diagram
Full electrical architecture diagram showing panels, strings, combiner box, inverter, disconnect, meter, and grid connection. Toggle cables, specs, power flow, and cable sizing. Supports all 4 connection modes.
📄 Report
Printable technical report with system overview, installation details, electrical config, energy production, financial analysis, bill of materials, installation notes, and environmental impact.
Canvas Tools
🔘 Visibility Toggles
The toolbar above the canvas has toggle buttons to show/hide layers:
| Toggle | Shows | Default |
|---|---|---|
| Dims | Section dimensions (width × height labels) | ON |
| Rails | Mounting rail lines under panels | ON |
| Mounts | Mounting point circles | ON |
| Terminals | + and - terminal markers on each panel | ON |
| Wiring | All cable connections | ON |
| DC+ | Positive DC cables (red) | ON |
| DC- | Negative DC cables (black) | ON |
| Labels | Panel numbers and string assignments | ON |
| Grid | Reference grid overlay | OFF |
| MPPT | Color-coded MPPT string groups | OFF |
| Shade | Shading simulation overlay | OFF |
🔍 Zoom & Pan
- Scroll wheel — zoom in/out
- Click + drag — pan the canvas
- +/− buttons — step zoom
- Home button — reset to default view
🛰 Satellite / Roof Overlay PRO
Click Overlay to open the overlay panel. Upload a satellite or roof photo, then adjust opacity, scale, and rotation to align it with your panel layout. Use Move mode to drag the image into position.
Exporting & Saving
💾 Save & Load
- Save — downloads a .json file (anonymous) or saves to cloud (signed in)
- Load — opens a file picker to load a previously saved .json project
- Cloud-saved projects appear in your Dashboard at /dashboard
📤 Export Formats
| Format | Content |
|---|---|
| CSV | Spreadsheet with all calculated values |
| PNG | Canvas layout image |
| Technical report document | |
| Permit PDF | 8-page compliance package (cover, layout, diagram, wiring, cable sizing, BOM, financial, compliance) PRO |
| JSON | Full project data (can be loaded back) |
| Browser print dialog for the report |
🔗 Shareable Client Proposals
Use the client proposal flow to publish branded share links. Customers can review layout, system size, savings, and accept the offer directly from the proposal page.
🏢 Branding
Click Branding in the header to set your company name, logo, installer name, phone, and email. This information appears on proposal and PDF exports and is saved in your browser for future use.
Teams & Collaboration
Available for signed-in users on Pro and Business plans.
- Go to Dashboard (click your avatar → My Projects)
- Scroll to the My Teams section
- Click Create Team and enter a team name
- Invite members by email — they receive access to shared projects
- Roles: Owner (full control), Admin (manage members), Member (view/edit)
Tips & Keyboard Shortcuts
⌨️ Shortcuts
💡 Pro Tips
- Auto orientation — leave orientation on "Auto" and the app will test both portrait and landscape, picking whichever fits more panels
- Auto-Config strings — click the Auto-Config button after selecting your inverter to instantly optimize string count
- Multiple sections — copy a roof face, set a reference, then use Mirror X/Y to stack matching upper/lower or left/right roof areas fast
- Exclusion zones — use Draw Zone mode for quick placement directly on the canvas
- Dark mode — click the 🌙 button in the header for comfortable evening design sessions
- Language memory — your chosen language is remembered across the app, dashboard, guide, and account pages
- PVGIS data — selecting a European city auto-fetches real irradiance data, replacing default estimates
- System Diagram — toggle Cable Sizing in the diagram tab to see a detailed cable routing panel