SMA Sunny Design Review: Features, Pricing & Pros vs Cons (2026)

SMA Sunny Design sits in an unusual position in the solar software market. It is free, it runs in a browser, and it is backed by one of the oldest inverter manufacturers in the industry — SMA Solar Technology AG, founded in 1981, with about 3,500 employees across 19 countries and €1,516 million in sales in 2025, according to the SMA company page. That combination makes it one of the most downloaded PV design tools among European installers, and a frequent first tool for new solar businesses.

We tested Sunny Design across residential rooftop, battery-storage, and off-grid scenarios for this review. The short version: as an engineering tool for SMA-based systems, it is excellent value. As a complete design-to-proposal workflow for a growing installer, it has clear ceilings — especially around multi-brand components, sales documentation, and commercial bankability.

This review covers current pricing, the free vs PRO feature split, real-world strengths and limits, and the cloud alternatives worth comparing before you commit your design workflow to any single-vendor tool.

In this guide:

• What Sunny Design is, who builds it, and who it serves
• Sunny Design pricing: free tier vs PRO at €600/year
• Core features tested: roof planning, shading, string design, off-grid
• Where the tool falls short for installers and EPCs
• Sunny Design vs cloud alternatives — head-to-head table
• What most installers get wrong about free design software
• Practical guidance: when to use it, when to move on

What Is SMA Sunny Design?

SMA Sunny Design is a free PV system planning tool that runs in a web browser, on iPad, and on Android tablets. It designs grid-connected PV systems with or without battery storage, off-grid island systems, and hybrid systems, using SMA’s component database and high-resolution meteorological data, according to the SMA product page.

The tool has existed in various forms for over a decade. The older Windows desktop version (Sunny Design 3) has been superseded by the web version, which is now on version 6.10. Recent releases added team workspaces with roles and permissions (6.0), Google Solar API integration for roof planning (5.9), and per-project team permissions (6.10).

Company and Product Background

SMA is one of the world’s largest string-inverter manufacturers. That context matters: Sunny Design is free because it supports SMA’s hardware ecosystem. The design logic, validation rules, and device database center on SMA inverters — Sunny Boy, Sunny Tripower, Sunny Island, and the Sunny Central line.

Target users: residential and small-commercial installers working with SMA hardware, system planners who need quick yield and self-consumption estimates, and off-grid designers using the Sunny Island platform. It is not positioned as a sales platform or a multi-brand engineering suite.

Sunny Design Pricing: Free vs PRO

Sunny Design is free, with no project limits, no credit card, and no trial expiry. The paid tier, Sunny Design PRO, costs €600 per year (net) with a 1-month free trial, according to the SMA product page.

Feature Split by Tier

The anonymous mode is genuinely useful for a quick string-sizing check. Registration (still free) opens project saving, off-grid design, and custom components. PRO is aimed at planners designing complete energy systems — PV plus battery, heat pump, combined heat and power (CHP), and EV charging in one simulation.

How the Pricing Compares

Free is a real price advantage. But as we cover below, the €0 price comes with constraints that cost time elsewhere in the workflow.

Core Features Tested

Sunny Design’s core strength is electrical design around SMA hardware, and it shows. The string-sizing logic checks module voltage windows against inverter maximum power point tracker (MPPT) inputs, flags overdimensioning, and proposes complete inverter configurations automatically.

Visual Roof Planning and Shading Analysis

The roof planning module builds 2D/3D building models from map data, with predefined roof shapes, dormers, chimneys, and external objects like trees and walls. Version 5.9 added Google Solar API data — solar potential maps and altitude profiles — for 3D roof planning.

Shading analysis calculates annual shading per roof surface and per module, shows the percentage of module shading, and animates the shadow course for any point in time. Complex scenes run on SMA’s server; simple scenes can compute directly in the browser, which is noticeably faster.

This is solid residential-grade shading work. It is not a physics-validated simulation in the class of dedicated solar shadow analysis software, but for SMA-based rooftop proposals it is more than adequate.

String Design and Electrical Validation

String planning runs inside the visual roof planner, with automatic polystring design, string-assembly plans, and a downloadable schematic circuit diagram covering the system from modules to grid connection. Version 6.10 added a warning when the voltage difference between MPPTs exceeds 80 V on CORE2 and STP125 inverters — the kind of detail that prevents real design errors.

For installers learning inverter sizing and string configuration, the automatic design suggestions are a genuine teaching tool. The catch: every suggestion is an SMA device. If you need to compare a Fronius or SolarEdge configuration, the tool cannot do it. The same applies to inverter clipping analysis — the ratios are validated against SMA input limits only.

Off-Grid and Hybrid Design

The registered free tier designs off-grid island systems and PV-diesel hybrid systems around the Sunny Island battery inverter. This is rare at a €0 price point. PV supplied more than 10% of global electricity consumption for the first time in 2024, according to the IEA PVPS Snapshot 2025, and off-grid and weak-grid design is a growing niche where Sunny Design has few free competitors.

Sunny Design PRO: Sector-Coupled Systems

PRO simulates complete energy systems: PV, battery storage, heat pumps (heating and cooling), CHP units, heating rods, and EV charging with PV-optimized charging logic. It imports load profiles, manages purchase and feed-in tariffs including dynamic time-series tariffs, and exports time series for further analysis.

Peak-load-shaving simulation for commercial batteries and a PowerPoint project exposé round out the tier. For German-market energy consultants designing sector-coupled home systems, PRO is well matched to that workflow.

User Experience and Learning Curve

The interface is clean and task-oriented. A first complete residential design — location, roof model, module layout, inverter selection, yield estimate — took us about 40 minutes on first use, and under 15 minutes by the third project. Quick planning mode strips the workflow to the essential inputs, which suits on-site tablet use.

Documentation is thorough. SMA publishes an operating manual, release notes for every version, and tutorial videos. The community of SMA installers is large enough that most edge-case questions have an answered forum thread.

Team features arrived only in version 6.0, and they show it. Roles, permissions, and shared workspaces work, but there is no commenting, no change history, and no live multi-user editing. This is project sharing, not collaboration in the sense sales-led teams expect from cloud platforms.

Where Sunny Design Falls Short

Sunny Design’s limits follow directly from its business model: it is a free tool that supports SMA hardware sales. Four gaps matter most for installers.

1. Single-brand electrical design. Module selection covers all common manufacturers, but inverter and battery-inverter design is SMA-only. Installers quoting 2–3 inverter brands per project — common practice in competitive residential markets — must run parallel designs in other manufacturers’ tools or estimate manually.

2. No sales layer. The output is project documentation: a technical report with layout, yield forecast, self-consumption analysis, and a profitability summary. There is no branded proposal template system, no eSignature, no quote pricing configurator, and no customer portal. Teams using solar proposal software expect the design to flow into a customer-ready document without re-typing numbers into a separate tool.

3. Financial depth is assessment-level. The profitability section models self-consumption, feed-in, and system costs. It does not produce lender-grade IRR (internal rate of return), NPV (net present value), or P75/P90 exceedance metrics. A dedicated generation and financial tool covers that ground for financed commercial projects.

4. No commercial structures. There is no carport or tracker design workflow. Large-scale projects are supported with DC combiner design, but the commercial structural options stop at flat and pitched roofs.

Sunny Design vs Cloud Alternatives

The right comparison for Sunny Design is not PVsyst — it is the cloud design platforms installers use for daily quoting. Global solar installations hit a record 597 GW in 2024, according to SolarPower Europe’s Global Market Outlook 2025–2029, and most of the distributed-generation share of that volume is quoted through tools in this table.

A few honest observations from the comparison. OpenSolar is the closest free rival and covers the sales workflow Sunny Design lacks, but its shading and electrical validation are shallower — our OpenSolar review covers the tradeoff in detail. PV*SOL produces deeper simulation reports but is desktop software with a steeper learning curve — see our PV*SOL review for the full breakdown. For the free-vs-paid tradeoff across the whole category, our free vs paid solar design software comparison maps the decision in detail.

What Most Installers Get Wrong About Free Design Software

The most common mistake we see is treating a free manufacturer tool as a complete design workflow. It is not. Sunny Design is an excellent engineering front end for SMA systems, and a poor substitute for a quoting process.

The math installers skip: if your designer spends 45 extra minutes per quote moving data between a free design tool, a spreadsheet, and a proposal document, that is roughly 15 hours per month at 20 quotes. At a loaded design cost of €35–€50 per hour, the “free” tool costs €525–€750 per month in re-work — more than a mid-range solar design software subscription. That is an industry-observed range, not a vendor claim; run the numbers against your own quote volume.

The second misconception: that a manufacturer’s yield estimate is neutral. SMA’s meteorological data and simulation are competent, but every manufacturer tool has an incentive to show its hardware in the best configuration. A brand-neutral platform has no such incentive. When a customer’s financing or a commercial client’s procurement team reviews your numbers, that independence matters. Module and system price trends also shift fast — the Fraunhofer ISE Photovoltaics Report tracks how quickly component cost structures change, and multi-brand databases keep pace across vendors.

The exception is the committed SMA shop. If 90%+ of your installs use SMA inverters and Sunny Island storage, the single-brand constraint barely binds, and the free tool’s depth is hard to beat.

Practical Guidance: When to Use Sunny Design

Use Sunny Design when your project profile matches these conditions:

• SMA hardware share above 90% of your installations. The design logic, validation, and device data are built for this.
• Residential and small commercial under 100 kW on pitched or flat roofs. The roof planner and shading analysis handle this segment well.
• Off-grid or hybrid projects on Sunny Island. Few free tools touch this capability.
• Early-stage businesses validating their design process before paying for software. Free is the right price at that stage.

Plan a paid cloud platform when these triggers appear:

• More than 15–20 quotes per month — the proposal assembly time overtakes the software saving.
• 2+ inverter brands in regular rotation — parallel manufacturer tools do not scale.
• Financed commercial projects — you need IRR/NPV reporting and consistent financial outputs from one cloud workspace; compare current plans and pricing before the quote volume forces the decision.
• Sales teams quoting live — cloud solar design platform access with instant proposal output shortens the sales cycle measurably.

One more practical note on inverters themselves: modern inverters do far more than DC-to-AC conversion — they provide grid services, monitoring, and storage integration, as the US Department of Energy explains. Choosing the design tool that matches your inverter strategy is as important as choosing the inverter. For a broader market view, our best solar design software roundup compares 8 platforms across these exact criteria.

Final Verdict

SMA Sunny Design earns a 7/10. It is the strongest free PV design tool for installers inside the SMA ecosystem, and its off-grid capability at €0 is genuinely unmatched. The string-sizing logic, roof planner, and Google Solar API integration reflect serious engineering investment.

It loses points where the business model draws the line: SMA-only electrical design, no branded sales proposals, no eSignature or CRM, assessment-level financials, and no carport or tracker workflows. The PRO tier at €600/year is fair value for sector-coupled simulation but buys none of those sales-side gaps.

Our recommendation: if SMA hardware dominates your pipeline, use Sunny Design as your engineering tool and pair it with a proposal layer. If you quote multiple brands, run more than 15–20 proposals per month, or chase financed commercial work, start with an all-in-one cloud platform — our cloud vs desktop solar design breakdown explains why the deployment model matters as much as the feature list — and treat manufacturer tools as validation checks, not the workflow.

Who Should Use Sunny Design — and Who Should Skip It

Best fit:

• Residential and small-commercial installers standardized on SMA inverters
• Off-grid and hybrid designers working with the Sunny Island platform
• New solar businesses building a design process before committing to paid software
• German-market energy consultants designing sector-coupled home systems (PRO tier)

Skip it if:

• You quote 2+ inverter brands and need comparable electrical designs for each
• Your sales process depends on branded proposals, eSignature, or live quoting
• You need lender-grade financial outputs or P75/P90 metrics for financed projects
• Your pipeline includes carports, trackers, or complex commercial structures

Next steps:

• Register for the free Sunny Design tier and run 3 real projects through it — roof planning, shading, and string design — before judging it.
• Time your current design-to-proposal workflow for one quote; if assembly outside the design tool exceeds 30 minutes, price out a cloud alternative.
• Book a SurgePV demo to compare multi-brand design, financial modeling, and branded proposals against your current stack in one session.

Frequently Asked Questions

Is SMA Sunny Design free?

Yes. Sunny Design is free to use in a web browser, on iPad, and on Android tablets, with no credit card and no project limits. The paid tier, Sunny Design PRO, costs €600 per year (net) and adds sector-coupled energy system planning, tariff management, load profile analysis, and extended project documentation. A 1-month free PRO trial is available.

What is the difference between Sunny Design and Sunny Design PRO?

Sunny Design (free) covers on-grid PV design, visual roof planning with shading analysis, off-grid and hybrid systems, and project saving. Sunny Design PRO (€600/year) adds planning of complete energy systems with integrated energy management — batteries, heat pumps, combined heat and power, and EV charging — plus 3D model import, tariff management, consumption and load profile analysis, time-series export, and extended documentation.

Can Sunny Design design systems with non-SMA inverters?

No. Sunny Design’s inverter and battery-inverter design logic is built around the SMA product catalog, including Sunny Boy, Sunny Tripower, and Sunny Island devices. PV module selection covers all common manufacturers, but if your projects use Fronius, SolarEdge, Huawei, or other inverter brands, the electrical design output will not apply. Multi-brand installers need a brand-neutral design platform.

Does Sunny Design include shading analysis?

Yes. Visual roof planning includes annual shading calculation for roof surfaces and individual modules, percentage-of-shading displays, and shadow-course animation for any selected time. Version 5.9 added Google Solar API data (solar potential and altitude profiles) for 3D roof planning. Complex scenes can be calculated on SMA’s server or in the browser for simple scenes.

Is Sunny Design good for commercial solar projects?

Partially. The free tier handles large-scale system projects including DC combiner design, and PRO adds peak-load-shaving battery simulation and commercial tariff modeling. However, there is no P75/P90 bankability output, no carport or tracker design, and the financial assessment is not lender-grade. Commercial EPCs above a few hundred kW typically pair it with dedicated simulation and proposal software.

What are the best Sunny Design alternatives?

For a comparable free tool, OpenSolar covers multi-brand design with proposals. PV*SOL (Valentin Software) offers deeper simulation for around €800/year. For an all-in-one cloud workflow — 3D design, physics-based shading, financial modeling, and branded proposals in one workspace — SurgePV is the strongest paid alternative. Aurora Solar serves US installers needing sales-focused proposals.

Does Sunny Design work on Mac, iPad, or offline?

Sunny Design runs entirely in a web browser, so it works on Mac, Windows, and Linux without any desktop install. Dedicated tablet apps exist for iPad and Android. There is no offline mode — the tool requires an internet connection, and the older Windows desktop version (Sunny Design 3) has been superseded by the web version.

Can Sunny Design generate customer proposals?

It generates project documentation — a technical report with system layout, yield forecast, self-consumption analysis, and profitability summary — and PRO adds a PowerPoint project exposé. These are engineering documents, not branded sales proposals. There is no eSignature, no pricing configurator for quotes, and no customer portal. Sales teams typically export the documentation and build the commercial proposal elsewhere.