Interactive solar panel and photovoltaic system simulation
About PVAlign Solar Panel & PV System Simulator
PVAlign is a free, browser-based interactive solar panel and PV system simulator for building complete solar power circuits. Connect PV, batteries, charge controllers, inverters, grid power, automatic transfer switches, protection, wiring, meters, and loads, then change the configuration and see how the estimated system responds.
Why PVAlign Exists
Connect theory to system behavior
Solar design is easier to understand when the relationships are visible. PVAlign joins educational content with an interactive electrical canvas so learners can move from a concept to a testable circuit in the same browser.
- 25 user-addable node types
- 9 reference circuit presets
- Live topology-aware results
- Free — no account required
How It Works
A circuit, not just a calculator
Each result comes from the equipment settings, the conductors, the connection topology, and the conditions applied to the complete system.
Place nodes
Add sources, storage, conversion equipment, protection, measurement, distribution, and loads to the canvas.
Connect terminals
Build electrically meaningful paths. Branch junctions connect conductors; wires that merely cross remain separate.
Enter ratings
Use component inspectors to configure datasheet values, operating limits, environmental conditions, and conductor properties.
Compare results
Inspect voltage, current, power, energy, losses, temperature, operating states, warnings, and protection behavior.
Current Component Catalog
25 interactive equipment nodes
These are the components available in the simulator now. The visual page shows the same SVG assets used on the circuit canvas.
Generation
Solar Panel
Models monocrystalline, polycrystalline, and thin-film environmental profiles alongside datasheet ratings, I-V behavior, shading, cell temperature, cold-design Voc, and series-parallel arrays.
Power control
MPPT Controller
Finds the calculated PV maximum-power point and converts array power for battery charging and a controlled DC load output.
Power control
PWM Controller
Models PWM operation near battery voltage, charge stages, current limits, night detection, and switchable load output behavior.
Energy storage
Battery
Tracks voltage, state of charge, stored energy, temperature, current limits, chemistry, and series or parallel bank behavior.
Conversion
Battery Inverter
Converts battery DC into selectable pure or modified sine-wave AC with efficiency, standby demand, DC limits, continuous output, startup surge protection, and load compatibility warnings.
Conversion
Hybrid Inverter
Coordinates PV, battery, AC loads, and the utility grid while applying MPPT, conversion, charge, discharge, surge, and voltage limits.
AC source
Utility Grid
Supplies compatible AC circuits and estimates import demand, exported power, accumulated energy, and simple energy cost.
AC source transfer
Automatic Transfer Switch
Models a two-source, two-pole, break-before-make ATS with normal and emergency source qualification, automatic or manual operation, live transfer countdowns, return and transition delays, contact ratings, and separate load-side output pairs.
Protection
Power Breaker
Provides two-pole AC or DC switching with circuit-type checks, inverse-time overload protection, and an instantaneous short-circuit trip.
PV protection
MC4 Fuse Connector
Models a compact single-conductor gPV fuse with PV-only terminals, current accumulation, a latched blown state, and a configurable DC voltage rating.
PV distribution and protection
PV Combiner Box
Combines two to eight parallel solar strings, models an isolating switch and independently latched 1–32 A gPV string fuses, and checks summed output-current and design-voltage ratings.
DC protection
Low Voltage Disconnect
Protects battery-powered DC circuits with chemistry-aware thresholds, hysteresis, and latched current- or maximum-input-voltage rating faults.
Control
SPDT Relay
Uses an electrically isolated AC or DC coil to move COM between NC and NO, with pickup/dropout hysteresis, coil consumption, voltage warnings, and contact-current limits.
High-current control
DC Contactor
Uses an isolated DC coil to close a normally-open positive contact, with realistic pickup/dropout hysteresis, coil consumption, switching-voltage limits, and contact-current warnings.
Distribution
Extension Socket
Distributes one AC or DC source across two to eight outlet pairs and reports combined load, current, use, and overload state.
Electrical load
Appliance
Represents AC or DC constant-power, resistive, constant-current, motor, and compressor loads with startup and duty-cycle behavior.
Compressor load
Refrigerator
Models a dedicated AC refrigerator with power factor, compressor startup surge, thermostat duty cycling, voltage limits, runtime, energy use, and independent width and height controls.
Resistive heating load
Rice Cooker
Models a fixed-AC rice cooker as a resistive heating load with voltage-dependent power, operating-voltage protection, live readings, runtime, and accumulated energy.
Motor load
Washing Machine
Models a fixed-AC washing machine with motor power factor, startup surge, intermittent agitation duty cycling, voltage limits, runtime, and energy use.
Electronic load
Television
Models a fixed-AC television as a constant-power electronic load with power factor, brief startup demand, voltage protection, and energy tracking.
Resistive heating load
Electric Kettle
Models a fixed-AC 1,500 W kettle whose heating power and current respond to the delivered voltage, with live state and accumulated energy.
Electronic load
Laptop
Models a laptop and its fixed-AC power adapter as a constant-power load with power factor, brief startup demand, voltage limits, runtime, and energy use.
Motor load
Fan
Models a three-speed AC or DC fan with editable watts, RPM, startup demand, operating-voltage range, and runtime.
Measurement
Multimeter
Measures simulated AC/DC voltage, current, watts, VA, power factor, frequency, available power, and flow direction.
Measurement
PV Analyzer
Tests an isolated panel or array for Voc, Isc, Vmp, Imp, Pmax, and a simulated 41-point current-voltage curve.
Wire junctions are created directly on conductors and act as compact branch nodes, bringing the modeled node count beyond the equipment catalog.
Who It Is For
Learn, explain, and explore
PVAlign supports curiosity at different levels while keeping the boundary between an educational estimate and an approved electrical design clear.
01
Students & Educators
Turn PV, battery, grid, power-conversion, protection, and circuit-topology concepts into visible experiments that can be changed one variable at a time.
02
DIY & Off-Grid Learners
Compare component ratings and wiring arrangements before checking a promising concept against real product documentation.
03
Installers & Engineers
Explore early configurations, demonstrate operating relationships, and identify questions that require detailed engineering or code review.
04
Homeowners & Planners
Build practical intuition about solar production, storage, inverter demand, grid use, and why system ratings must work together.
Current Simulation Model
What PVAlign models today
The engine resolves physics-informed steady-state operating points and applies topology-aware limits, losses, protection, and safety warnings.
| System area | Implementation | Current scope |
|---|---|---|
| PV generation | I-V curve, temperature, irradiance, shading, bypass behavior | Steady-state module and reducible array model |
| PV array topology | Series, parallel, and series-parallel networks | Shared-current and shared-voltage operating points |
| Charge controllers | Separate MPPT and PWM behavior | Limits, losses, charging stages, load output, and faults |
| Battery storage | Lead-acid, LiFePO₄, and lithium-ion | SOC, energy, current limits, charge acceptance, and bank safety |
| Power conversion | Battery and hybrid inverter models | Efficiency, standby, surge, DC limits, and AC demand |
| Automatic source transfer | Two-source, two-pole open-transition ATS | Normal and emergency voltage/frequency qualification, preferred-source logic, manual modes, transfer and return timers, break-before-make delay, and contact-load checks |
| Loads | Configurable loads, six dedicated household appliances, and three-speed fans | Fixed AC compatibility where required, constant-power and resistive behavior, motor or compressor startup, duty cycles, voltage windows, runtime, and energy |
| Conductors | Copper or aluminum cable model | Resistance, voltage drop, I²R loss, ampacity, and temperature |
| Protection and control | AC/DC breaker, MC4 gPV fuse, PV combiner box, low-voltage disconnect, SPDT relay, and DC contactor | Breaker and fuse opening behavior, parallel-string combining, battery-aware LVD thresholds, current and voltage ratings, and isolated coil-controlled switching with hysteresis |
| Interactive canvas | Mouse, touch, minimap, recentering, and saved display preferences | User-defined 10%–500% zoom limits, grid and map visibility, terminal-selection sizing, and current, loss, or temperature wire labels |
| Measurement | Multimeter and PV I-V analyzer | Live electrical readings and isolated array testing |
| Environment | Time, weather, irradiance, ambient temperature, and wind | Shared conditions with forward battery and energy progression |
Modeling Principles
Useful estimates require honest limits
PVAlign uses electrical equations, graph-based topology, component models, and documented assumptions to make system relationships understandable. Displayed precision improves readability; it does not represent laboratory measurement accuracy or design certification.
Real equipment and installations include manufacturer-specific controls, transient behavior, thermal conditions, protection curves, aging, site details, and code requirements that a general-purpose educational model cannot fully reproduce.
Use PVAlign for learning, comparison, and preliminary planning. Verify safety-critical ratings against current manufacturer documentation and applicable electrical codes, with qualified professional review where required.
See the editorial policy and simulation methodology for the publisher identity, source hierarchy, calculation standards, AI-use disclosure, and corrections process behind PVAlign content.
Questions & Answers
Frequently asked questions
Current answers about PVAlign's features, intended use, and simulation limits.
General
What is PVAlign?
PVAlign is a free, browser-based interactive solar panel and photovoltaic system simulator and learning platform. It lets users build complete solar power circuits with PV panels, batteries, charge controllers, inverters, utility grid sources, protection devices, wiring, meters, and loads, then estimates how voltage, current, power flow, energy, losses, charging, discharging, and operating states change with the circuit.
Who is PVAlign designed for?
PVAlign is designed for students, educators, homeowners, DIY and off-grid learners, installers, engineers, and anyone who wants to explore photovoltaic system behavior before moving to detailed product, site-specific, permitting, or code-compliant design.
Do I need an account or installation?
No. The simulator runs in a modern web browser and does not require an account to begin building and exploring circuits.
Current Simulator
What nodes can I add to a PVAlign circuit?
The current catalog includes solar panels, MPPT and PWM charge controllers, batteries, battery and hybrid inverters, the utility grid, automatic transfer switches (ATS), configurable one- through four-gang AC wall switches with connectable canvas terminals, two-conductor surge protective devices (SPDs), ground and protective-earth references, power breakers, MC4 gPV fuse connectors, PV combiner boxes, low-voltage disconnect modules, SPDT relays, DC contactors, extension sockets, configurable appliances, dedicated LED light bulb, refrigerator, rice cooker, washing machine, television, electric kettle, and laptop loads, fans, multimeters, and PV analyzers. Wire junctions are created when a branch is connected to an existing conductor.
Can PVAlign simulate series and parallel solar panels and batteries?
Yes. PVAlign resolves supported series, parallel, and series-parallel PV arrays as well as series and parallel battery banks. It can also identify conditions such as mismatched ratings, unsafe battery-bank conditions, shorts, reversed polarity, floating sections, and invalid loops.
Can I compare MPPT and PWM charge controllers?
Yes. MPPT and PWM are modeled separately. PWM operation pulls the PV array closer to battery voltage during charging, while MPPT searches the array curve for a calculated maximum-power operating point and models DC-to-DC conversion, efficiency, and current limits.
Can PVAlign simulate hybrid inverter behavior?
Yes. The hybrid inverter model can coordinate PV input, battery charging and discharging, AC load demand, utility-grid connection, conversion losses, standby demand, voltage and current limits, MPPT behavior, and grid-frequency conditions.
Can I compare pure sine wave and modified sine wave battery inverters?
Yes. The Battery Inverter node can output pure sine wave or modified sine wave AC. Pure sine wave is the utility-like default. When modified sine wave is selected, PVAlign identifies connected motor, compressor, fan, and electronic loads that may run hotter, become noisy, start unreliably, create interference, or malfunction. Resistive heating loads are treated as generally compatible, but real equipment requirements must always be checked with its manufacturer.
Does weather and time affect the simulation?
Yes. The optional Environment panel provides clear, partly cloudy, cloudy, rain, and manual conditions. Time, irradiance, ambient temperature, and wind can affect opted-in panels, conductor temperature, battery progression, load energy, runtime, and grid-import totals.
Can I save or share a circuit?
Yes. You can save a circuit in the current browser, import or export circuit data as JSON, and export a PNG image for printing, documentation, or sharing.
Accuracy & Safety
How accurate is the PVAlign solar simulator?
PVAlign provides physics-informed steady-state estimates within documented assumptions. It is designed to make system relationships visible, but displayed precision is not laboratory measurement accuracy and the model does not reproduce every manufacturer algorithm, transient, shading pattern, thermal condition, installation detail, aging effect, utility rule, or electrical-code requirement.
Does PVAlign perform safety checks?
The simulator checks many connection and operating conditions, including polarity, AC/DC compatibility, voltage classes, battery chemistry, PV overvoltage, shorts, array mismatch, conductor loading, breaker type, ATS source voltage and frequency qualification, ATS contact loading, SPD protective-earth continuity, surge let-through and cartridge endurance, MC4 and combiner gPV fuse ratings, combiner output loading, LVD rating faults, relay coil type and voltage, relay contact current, DC contactor coil and switching ratings, and incompatible load supply. These checks are educational and are not a safety certification.
Can I use a PVAlign result for a real installation?
Use PVAlign for education, comparison, experimentation, and preliminary planning—not as the sole basis for purchasing, permitting, construction, grid connection, or safety approval. Verify equipment against current manufacturer documentation, applicable electrical codes, site conditions, utility requirements, and qualified professional calculations.
Start with a reference circuit or build your own