Use MicrogridModeler when the immediate job is an auditable browser-first off-grid PV + battery + diesel feasibility screen with deterministic dispatch and easy-to-explain assumptions. Use REopt when the problem is broader DER optimization for buildings, campuses, grid-tied sites, resilience, emissions, or API-backed studies. Use HOMER Pro, Xendee, SAM, or spreadsheets when their workflow better matches teaching, enterprise portfolio design, technology finance, or a quick hand calculation.
Key takeaways
- MicrogridModeler is purpose-built for deterministic off-grid PV + battery + diesel feasibility that a planner can rerun and audit in the browser.
- REopt is a strong choice for optimizing DER mix, sizing, dispatch, economics, and resilience across grid-tied and off-grid buildings, campuses, and microgrids.
- HOMER Pro remains useful when a study needs a mature desktop microgrid workflow, broad hybrid-system modules, and extensive sensitivity analysis.
- Xendee is best considered when the work expands into DER portfolios, power-flow and control, EV infrastructure, proposal workflows, and operations.
- Spreadsheets and SAM can teach important finance and technology fundamentals, but they are not always enough for constraint-enforced off-grid dispatch decisions.
Comparison matrix
| Criterion | MicrogridModeler | HOMER Pro | REopt | Xendee |
|---|---|---|---|---|
| Best first question | What is the lowest-cost feasible off-grid PV + battery + diesel design I can defend? | Which hybrid-system configurations and sensitivities should I explore in a mature desktop model? | Which DER mix, size, and dispatch improves economics, resilience, emissions, or outage support? | How do I screen, design, propose, and operate DER or microgrid projects across many sites? |
| Primary workflow | Open the browser modeler, set site assumptions, run deterministic sizing, inspect dispatch and economics. | Build a desktop project, simulate candidate systems, optimize, and run sensitivity cases. | Use the web tool, API, or open-source model to optimize DER sizing and dispatch around selected goals. | Use a commercial platform covering discovery, proposals, design, operation, mobility, and services. |
| Best-fit project | Remote clinics, telecom sites, islands, schools, camps, and off-grid feasibility studies. | Hybrid microgrid consulting, teaching, and studies that need wind, diesel, PV, batteries, grid options, or add-on modules. | Buildings, campuses, and microgrids where cost, resilience, critical load support, and DER optimization matter. | Enterprise DER portfolios, campuses, fleets, EPC proposals, and power-flow-aware microgrid programs. |
| Audit posture | Deterministic browser run, visible assumptions, dispatch traces, and reproducible run package. | Documented desktop project, sensitivity outputs, reports, and established professional adoption. | Public web tool plus API and open-source model paths, with solver inputs and scenario assumptions to preserve. | Commercial reports combining economic, network, control, and portfolio assumptions. |
| Main caution | Narrow scope by design: PV, battery, and diesel are the current modeling center. | Desktop setup, licensing, and broad options can be more process than a first-pass browser screen needs. | Powerful optimization can require careful scenario framing before non-specialists trust the result. | The platform may be more system than a student, one-off site planner, or simple remote feasibility task needs. |
Direct answer
MicrogridModeler and REopt are both serious planning tools, but they are not trying to be the same product. MicrogridModeler is the cleaner fit when the question is: can this off-grid site be served with PV, batteries, and diesel at the lowest feasible lifecycle cost, and can another analyst reproduce the answer?
REopt is the better fit when the question is broader: which distributed energy resources should a building, campus, or microgrid install and dispatch to improve economics, resilience, emissions, or critical-load support? The REopt web tool page describes DER economic viability, mix, sizing, dispatch, and reliability analysis across grid-tied and off-grid buildings, campuses, and microgrids.
Where MicrogridModeler fits
MicrogridModeler is intentionally focused. It centers off-grid PV + battery + diesel feasibility, deterministic sizing, hourly dispatch, and lifecycle economics in a browser workflow. That makes it useful when a site planner, EPC analyst, or student needs to open the model, change a few defensible assumptions, and explain why the result changed.
The practical advantage is auditability. A remote site study often fails when the model becomes a black box or when two analysts cannot recreate the same result. MicrogridModeler keeps the early-stage scope narrow enough that the answer can be inspected: load, resource, generator constraints, storage assumptions, dispatch, renewable fraction, diesel-only baseline, NPC, and LCOE.
- Use it for first-pass off-grid PV + battery + diesel feasibility.
- Use it when a browser-first workflow matters for classroom, client, or field access.
- Use it when deterministic repeatability is more important than exploring every DER technology.
- Use it when the deliverable needs dispatch evidence, not only a headline LCOE.
Where REopt fits
REopt is a strong public-sector and research-grade option when the planning question is broader than one off-grid hybrid. Its web tool and model ecosystem support economic viability analysis for hybrid DERs, optimization of system mix, sizing, and dispatch, and resilience analysis such as how long a system can sustain critical loads during outages.
That makes REopt especially relevant for campuses, facilities, public agencies, and analysts who want web, API, or open-source workflows. It can be a better fit than MicrogridModeler when the study includes grid-tied tariff effects, resilience objectives, emissions goals, or DER combinations outside a focused PV + battery + diesel remote-site screen.
- Use it for DER mix, sizing, dispatch, economics, and resilience framing.
- Use it when the API or open-source model path is part of the workflow.
- Use it when outage support and critical-load duration are central questions.
- Use it when the site is grid-tied or campus-scale and not just a remote diesel offset problem.
How HOMER Pro, Xendee, SAM, and spreadsheets compare
HOMER Pro is still the incumbent many analysts know. UL Solutions describes HOMER Pro as software for exploring lowest-cost solutions for remote power systems, microgrids, and islanded utilities, with simulation, optimization, sensitivity analysis, and add-on modules. It remains a good fit for hybrid-system teaching and consulting when a desktop workflow is acceptable.
Xendee is broader and more commercial-platform oriented. Its current platform page emphasizes DER design and operation, EV infrastructure, powerflow and control, portfolio screening, proposal workflows, and 25-plus DER technologies. That is useful for enterprise teams, EPCs, consultants, fleets, campuses, and portfolios; it can be more than a student or one-site off-grid feasibility task needs.
SAM and spreadsheets are adjacent rather than direct substitutes. NREL describes SAM as a free desktop application for techno-economic analysis of energy technologies, including PV, battery storage, wind, and financial models. Spreadsheets are excellent for teaching assumptions and checking simple economics, but they should not be the final authority when hourly constraints, generator minimum loading, state of charge, and unmet-load rules decide feasibility.
How to compare the tools fairly
A fair comparison starts with the same problem statement. If one tool is allowed unmet load, another forbids it, and a spreadsheet hides it, the result is not a software comparison. It is an assumptions mismatch.
Before choosing a tool, write a one-page model brief. Include the hourly load profile, resource data source, diesel fuel cost, generator minimum loading, battery usable capacity, battery round-trip efficiency, replacement costs, discount rate, project life, outage requirement, unmet-load rule, and the exact financial metric being optimized.
- Compare dispatch plots and constraint violations before comparing LCOE.
- Separate sizing optimization from dispatch-only simulation.
- Record model versions, source pages, data dates, and exported inputs.
- Ask which hour makes the design hard: cloudy week, load spike, outage window, or fuel-price scenario.
- Use a spreadsheet as a sanity check, not as a replacement for hourly feasibility.
A note for students
Students should use this comparison to learn tool selection, not tool loyalty. MicrogridModeler is helpful for seeing how PV, storage, diesel, dispatch, constraints, and lifecycle economics connect in a browser. REopt is helpful for understanding formal DER optimization and resilience framing. HOMER Pro is helpful for classic hybrid-system sensitivity studies. SAM is helpful for technology and finance fundamentals.
The best assignment is to run the same simplified site in more than one tool and then explain why results differ. Usually the answer is not that one tool is magic. It is the load shape, constraint definition, storage model, fuel assumption, replacement schedule, or objective function.
Bottom line
Choose MicrogridModeler when the job is fast, auditable off-grid PV + battery + diesel feasibility. Choose REopt when the job is broader DER optimization for economics, resilience, critical loads, emissions, or API-driven analysis. Choose HOMER Pro when a mature desktop hybrid-system environment is the right fit. Choose Xendee when the work is portfolio-scale and operational. Choose SAM or spreadsheets when the learning goal is technology finance or transparent arithmetic.
A good microgrid study is not won by picking the most complex tool. It is won by matching the tool to the decision and preserving enough evidence that the next analyst can rerun the study.
Sources and review notes
This comparison is based on public product and documentation pages reviewed for the 2026 planning context. Always verify current licenses, modules, and pricing before making procurement decisions.
FAQ
Is MicrogridModeler a REopt alternative?
Yes, for a narrower job: browser-first off-grid PV + battery + diesel feasibility with deterministic dispatch and auditable assumptions. REopt is broader for DER mix, sizing, dispatch, economics, resilience, and API or open-source workflows.
When should I use REopt instead of MicrogridModeler?
Use REopt when the project is grid-tied, campus-scale, resilience-focused, emissions-focused, API-driven, or involves DER optimization beyond a focused PV + battery + diesel off-grid screen.
When should I use MicrogridModeler instead of REopt?
Use MicrogridModeler when the deliverable is an explainable first-pass off-grid feasibility result for PV, battery, and diesel, and the team needs quick browser access, reproducibility, and visible hourly dispatch.
Can I compare MicrogridModeler, REopt, and HOMER Pro directly?
Yes, but only if you align load, weather, fuel price, battery assumptions, generator constraints, project life, discount rate, and unmet-load rules. Otherwise the differences may come from inputs rather than software behavior.
Are spreadsheets enough for microgrid feasibility?
Spreadsheets are useful for simple checks and teaching, but they are usually not enough for final off-grid feasibility because hourly dispatch, state of charge, generator constraints, and unmet-load rules can change the answer.
Run the comparison on your own site
Open a benchmark, change the load or cost assumptions, and inspect the dispatch behind the economics.