Solar Software P3 Reference 4 min read Reviewed July 8, 2026 Keyur Rakholiya Keyur Rakholiya

PowerFactory (DIgSILENT)

DIgSILENT PowerFactory is the industry-standard power system simulation tool for utility-scale solar grid studies.

Definition

DIgSILENT PowerFactory is the leading commercial power system simulation tool used for utility-scale solar grid interconnection studies — load flow, short circuit, harmonics, dynamic stability, and protection coordination.

Key Takeaways

  • PowerFactory = DIgSILENT’s power system simulation tool.
  • Used for utility-scale grid connection studies.
  • Load flow, short circuit, dynamic stability.
  • Required for system impact studies on large solar plants.
  • Industry standard; expensive commercial license.

What PowerFactory Actually Models

PowerFactory sits at a different layer than a solar design tool like PVsyst or Helioscope. Those tools model the plant itself — how much sun hits the modules, how the strings and inverters are laid out, how many kWh come out at the end of the year. PowerFactory models the grid’s view of the plant: what happens on the utility network once that plant is connected.

That view is built from a handful of standard study types:

  • Load flow — steady-state voltage and power flow across the network with the plant online, checking for voltage violations or thermal overloading on existing lines and transformers.
  • Short circuit — how much fault current the plant contributes during a fault, which determines whether existing switchgear and protection settings still hold up.
  • Harmonics — how much distortion the plant’s inverters inject back onto the network, generally checked against standard limits such as IEEE 519.
  • Dynamic/transient stability — how the plant responds during and after a grid disturbance (a fault, a frequency swing), including fault-ride-through behavior.
  • Protection coordination — verifying relay and breaker settings still operate correctly with the new generation source on the network.

Grid operators and utilities typically require some or all of these studies — a “system impact study” — before they will approve interconnection for an MW-scale solar plant. That’s why PowerFactory shows up almost exclusively on utility-scale and large ground-mount projects rather than rooftop or small commercial work: the interconnection review process for those larger plants explicitly asks for this class of study.

PowerFactory vs. a Solar Yield Tool

A useful way to keep the distinction straight: if PVsyst answers “how much energy will this array produce,” PowerFactory answers “what does connecting this array do to the grid it’s plugging into.” A large solar plant typically needs both studies run in parallel — one team validating the bankable yield case, another running the interconnection case — and the two rarely overlap in scope or in the software used.

Because PowerFactory and PVsyst answer different questions on the same project, it’s worth understanding both sides of that pair — our guide on accurate energy yield predictions covers why getting the yield case right matters for financing, which is the counterpart to the interconnection case PowerFactory runs. If you’re weighing where a grid-study tool like PowerFactory fits against design-stage software, Best Solar Design Software in 2026: 10 Platforms Ranked places it in context alongside PVsyst, Aurora, and Helioscope. The harmonics study that’s part of most PowerFactory interconnection packages is checked against limits explained in more depth in Qbits Energy’s harmonics and IEEE 519 glossary entry. And once a utility-scale plant clears its PowerFactory interconnection study and moves from paper to construction, our sister company Heaven Green Energy’s ground-mount solar EPC practice handles the build-out.

Frequently Asked Questions

5 commonly searched questions about PowerFactory (DIgSILENT).

What is DIgSILENT PowerFactory used for?
PowerFactory is used to run the power system studies utility-scale solar plants need to connect to the grid — load flow, short circuit, harmonics, dynamic/transient stability, and protection coordination. Utilities and grid operators typically require these studies before approving interconnection.
Who makes PowerFactory, and is it free?
PowerFactory is a commercial product from DIgSILENT GmbH. It is not free — licenses are priced for utilities, TSOs/DSOs, and engineering consultancies running grid impact studies, not for individual designers, which puts it out of reach for most residential or small commercial solar shops.
Do I need PowerFactory for a rooftop or small commercial solar project?
Generally no. PowerFactory is built for utility-scale interconnection studies on large ground-mount or MW-scale plants where the grid operator requires formal load flow, short circuit, and stability analysis. Rooftop and small commercial systems are typically screened under simpler utility interconnection rules and don't need a full PowerFactory model.
What's the difference between PowerFactory and PVsyst?
They answer different questions. PVsyst models how much energy a solar array will produce (bankable yield). PowerFactory models how that plant behaves on the grid — voltage impact, fault current contribution, harmonic distortion, and fault-ride-through response. A large utility-scale project typically needs both: PVsyst for the yield case, PowerFactory for the interconnection case.
What studies does a PowerFactory grid interconnection package usually include?
A typical system impact study package covers steady-state load flow (voltage and thermal loading), short circuit analysis (fault current levels for protection sizing), harmonics (distortion limits, often referenced against IEEE 519), dynamic stability (how the plant rides through grid disturbances), and protection coordination (relay and breaker settings).

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