HOMER Grid vs HOMER Pro for C&I Hybrid Projects

HOMER Grid vs HOMER Pro looks like a product comparison. The harder issue is model ownership. A commercial and industrial (C&I) project may have solar, a battery, grid supply, a generator, and an outage requirement. Both products can model parts of that system. The right choice depends on the decision that must survive review.

Direct answer. Choose HOMER Grid when a C&I project starts with the electricity bill, demand peaks, time-of-use periods, EV charging, and customer economics. Choose HOMER Pro when system architecture leads, including generators, multiple resources, controller logic, off-grid operation, or broad sensitivity analysis. A grid connection alone does not settle the choice.

This guide is for EPC engineers and developers who need a defensible purchase decision. It uses current UL Solutions product pages, official manuals, and prices observed on September 26, 2026. Prices can change, so confirm them before buying.

The real difference between HOMER Grid and HOMER Pro

HOMER Grid organizes the analysis around a facility’s commercial relationship with the utility. HOMER Pro organizes it around the physical and economic architecture of a microgrid. That framing is more useful than asking whether the project is grid-connected, because both products can handle a grid connection.

HOMER Grid is the clearer fit for bill reduction, peak management, EV charging, and tariff-based proposals. The current UL Solutions HOMER Grid page names demand-charge management, EV charging, resilience, feasibility analysis, and customer-facing reports as core uses.

HOMER Pro starts from a wider component and dispatch problem. The current UL Solutions HOMER Pro page describes annual simulation, configuration search, least-cost optimization, and sensitivity analysis for grid-connected and off-grid systems. Its scope includes the generator-heavy, weak-grid, and remote-site cases that gave HOMER its reputation.

Decision dimension	HOMER Grid	HOMER Pro
Primary business question	How can this facility reduce cost or add value behind the meter?	Which system architecture meets the load at the preferred lifecycle cost?
Natural starting data	Utility bill, interval load, tariff, export rule	Load, resources, component choices, costs, dispatch constraints
Strongest C&I use	Tariff-aware solar, storage, EV, and resilience analysis	Multi-resource microgrid design with generators or specialized components
Grid rate depth	Built into the main workflow	Basic rates in the main product, deeper work through Advanced Grid
Customer proposal emphasis	Explicit product feature	Technical summary and export are available, but the product centers system analysis
Licensing structure	One standard commercial plan plus enterprise options	Base, Professional, and Expert tiers with different module access

The mistake is treating those columns as sealed boxes. HOMER Pro with Advanced Grid reaches into tariff work. HOMER Grid reaches into islanding and resilience. The project question still decides the better working environment.

The C&I scenario matrix

The same equipment list can support different buying decisions. A factory with PV, battery storage, and a generator may need tariff savings today and extended island operation tomorrow. Select the product from the dominant review question, then test the secondary question explicitly.

C&I project scenario	Better starting product	Reason	Required cross-check
Grid-connected factory with a complex demand tariff	HOMER Grid	Tariff verification and peak-demand economics lead the study	Confirm the imported tariff against a real bill
Warehouse adding solar, storage, and EV charging	HOMER Grid	EV charging and tariff value sit in the main workflow	Test charging schedule and peak coincidence
Hospital seeking bill savings plus outage coverage	HOMER Grid in many cases	Daily tariff value and critical-load resilience both matter	Run separate outage cases and verify critical load
Mine with weak grid, diesel, PV, and storage	HOMER Pro	Generator dispatch and architecture dominate	Add Advanced Grid if rate detail affects the result
Remote industrial plant with no utility supply	HOMER Pro	Off-grid energy balance and fuel displacement lead	Stress-test fuel price and load growth
Campus comparing CHP, storage, PV, and grid service	Depends	Tariff-led cases favor Grid; resource-led cases favor Pro	Define the approval metric before model setup
Front-of-meter battery earning market revenue	Neither as the first choice	The decision is market-led rather than facility-bill-led	Review HOMER Front before choosing

This matrix is a start, not a substitute for scoping. A campus model can move from Grid to Pro when a generator, thermal load, or custom controller becomes central. A mine can move toward Grid when it has reliable utility service and the financial case rests on demand charges rather than fuel logistics.

Verdict. For a standard behind-the-meter C&I solar and storage proposal, HOMER Grid is usually the cleaner starting point. For a C&I microgrid where the generator, resource mix, or controller is the hard problem, HOMER Pro is usually the better engineering base. The word “hybrid” does not pick the product.

Tariff modeling and the overlap buyers miss

HOMER Grid makes tariff work easier to find, build, and explain. HOMER Pro can still perform serious grid-rate analysis when the Advanced Grid module is available. Any comparison that says Pro is only off-grid is out of date or incomplete.

The HOMER Grid 1.9 tariff manual supports three entry paths: its North American library, a saved user library, or a custom tariff. The advanced builder covers tiered rates, time-of-use periods, ratchets, contracted demand, real-time prices, and holidays. It also tells the modeler to verify both the tariff rates and the calculated bill.

That last step matters. A tariff file can load without representing the customer’s account. Contracted demand, power factor, export limits, riders, and effective dates can change the bill. The model should reproduce a known utility bill before the team uses it to forecast savings.

UL Solutions states that HOMER Grid’s database covers more than 90 percent of ZIP codes in the United States, Canada, and Mexico. That is a vendor-stated coverage figure, observed on September 26, 2026. It does not promise that every tariff version or customer rider is correct.

HOMER Pro reaches much of the same ground through Advanced Grid. Its official Advanced Grid page names real-time rates, scheduled rates, demand charges, peak shaving, grid extension, and random outages. Pro therefore remains credible when tariff economics sit inside a larger generator and resource study.

The buying choice becomes practical. Grid reduces tariff setup and proposal friction. Pro keeps the tariff inside a wider architecture model. Choose the friction you want the software to remove.

Resilience, islanding, and generator decisions

HOMER Grid can model resilience. HOMER Pro can model reliable grid service and outages. The meaningful split is how much of the project depends on a broad component set and dispatch logic beyond the utility bill.

The HOMER Grid resilience manual separates critical and non-critical loads. It can model a specified or random multi-day outage, plus whether the dispatch controller knows about the outage in advance. That supports facilities where daily bill savings and backup power share the same battery.

For a facility model, keep the normal-day and outage questions separate:

1. Validate the normal utility bill without an outage event.
2. Confirm the critical-load profile from an actual load schedule.
3. Run outage cases at different start times and operating conditions.
4. Inspect state of charge before and during each outage.
5. State whether the controller had advance notice in the model.
6. Compare the selected system against the stated resilience requirement.

HOMER Pro becomes more attractive as the asset stack gets harder. Its feature set includes multiple generator, battery, photovoltaic, wind, and other component choices, plus dispatch and sensitivity controls. The HOMER Pro 3.16 optimization manual also explains how the optimizer searches component sizes and ranks results by net present cost.

For a solar, storage, and diesel project, the hybrid solar diesel battery design guide explains the engineering sequence around the model. The HOMER Pro African hybrid walkthrough covers the Pro interface in more detail. Treat older price and performance figures in those posts cautiously until their sources are refreshed.

Current pricing and license structure

HOMER Pro and HOMER Grid use different commercial price structures. HOMER Pro sells tiered module access. HOMER Grid sells its standard commercial capability on a monthly or annual subscription. The prices below were visible on official pages on September 26, 2026.

Product and plan	Monthly option	Annual option	Included access noted by vendor
HOMER Pro Base	$187.50 per month	$1,575 billed annually	No optional modules included
HOMER Pro Professional	$373.50 per month	$3,100 billed annually	Choice of four modules
HOMER Pro Expert	$568.50 per month	$4,650 billed annually	All modules included
HOMER Grid monthly	$665 per month	Not applicable	One user, monthly billing
HOMER Grid annual	Not presented as a monthly contract	$4,200 billed annually	One user, training, second non-simultaneous computer activation

Sources: official HOMER Pro pricing and official HOMER Grid pricing, accessed September 26, 2026. Taxes, regional terms, academic offers, and enterprise arrangements may differ. Confirm the checkout or quote before approval.

Price alone can mislead here. A Pro Base license may look cheaper but require a module for the intended tariff or outage study. Grid may cost more than Pro Professional while saving tariff setup and customer-report work. Compare the complete project workflow, not the smallest price on the page.

Use this license review before purchase:

• List every required component and rate feature.
• Map each feature to the included plan or module.
• Confirm how many people need simultaneous access.
• Check training and support needs.
• Assign a price recheck owner before procurement.
• Keep the source page and observation date in the approval note.

Four worked selection cases

The product choice becomes clearer when the team writes the decision record in plain language. These four cases are illustrative. They show the reasoning path, not measured project results or vendor promises.

A factory battery sized around monthly demand peaks

The factory has reliable grid service, interval load data, and a tariff with demand charges. Its operations team wants solar and storage to reduce the monthly peak. Backup power is useful, but the investment committee first wants a bill comparison.

Start in HOMER Grid. The bill ledger leads because tariff logic and peak timing decide the storage value. Import the interval load, build or select the tariff, and reproduce a recent bill. Then add storage and solar cases. Run the resilience analysis after the normal bill model is stable.

HOMER Pro with Advanced Grid could address much of the same work. That option becomes attractive if the factory also has generators, several fuel choices, or custom control requirements. Without those complications, Pro adds model breadth that the approval team may never use.

A weak-grid mine with diesel backup

The mine has an unreliable grid, diesel generation, solar, and a proposed battery energy storage system. Fuel deliveries and generator loading shape operating cost. The utility bill matters, but it is one input in a wider supply problem.

Start in HOMER Pro. The asset ledger leads because the model must search across generation, storage, and dispatch choices. Advanced Grid can bring scheduled rates, outages, and demand charges into the same architecture model when needed.

Do not begin by asking which tool has the nicer tariff workflow. The model must first represent how the site stays powered. Once a candidate architecture exists, the team can test tariff and outage sensitivities without splitting the resource decision from the dispatch model.

A warehouse adding fleet charging

The warehouse plans rooftop solar, a battery, and electric vehicle chargers. Charging can create a new facility peak. The customer needs a proposal that explains bill impact, charging revenue assumptions, and backup limits.

Start in HOMER Grid. EV charging and demand-charge work are named product capabilities, and the customer-facing report sits close to the main workflow. Use measured facility load and a documented charger schedule. A generic daily energy total hides the timing that creates the peak.

The dispatch case should test more than one charging schedule. It should also state whether charging is deferrable. A battery that looks sensible under managed charging can look very different when vehicles arrive together and require immediate energy.

A campus with CHP and a complex tariff

The campus has combined heat and power (CHP), solar, storage, a utility tariff, and an outage requirement. The bill ledger and asset ledger both matter, so the software choice is less obvious.

First identify the approval owner. If the facilities team must compare tariff savings and a customer-ready proposal, begin in HOMER Grid. If the engineering team must select among generators, thermal resources, and dispatch strategies, begin in HOMER Pro with the needed modules.

Then build a secondary validation case for the other ledger. Keep inputs under one controlled register, even if the team uses two products. Load, tariff, component cost, and outage assumptions should not acquire different values merely because they live in different files.

When one project needs two models

A project may need two models when no single output answers both the investment question and the engineering question. Two files are justified only when each has a named owner, purpose, and reconciliation step.

An EPC might use HOMER Pro to settle a generator, PV, and battery architecture. The commercial team might then use HOMER Grid for a tariff-led customer proposal. That sequence can work, but the second model must inherit controlled inputs from the first. It should not become a fresh set of assumptions.

Use a simple handoff register:

Shared item	Source of truth	Reconciliation check
Load profile	Cleaned interval-data file	Same timezone, units, gaps, and growth basis
PV production	Approved yield dataset	Same annual and interval production basis
Battery	Selected datasheet and cost record	Same power, energy, efficiency, and limits
Tariff	Current utility document	Same effective date, riders, and export treatment
Financial assumptions	Approved investment memo	Same currency, discount basis, and project term
Outage case	Approved critical-load schedule	Same load, duration, timing, and controller knowledge

Name the model that controls each decision. If the products disagree, return to the shared inputs before debating the optimizer. Most unexplained differences begin in the data and scenario definitions, not in a mysterious software error.

The Three-Ledger Selection Test

The Three-Ledger Selection Test ties the software choice to the record that decides whether the project proceeds. It prevents a familiar failure: buying a tool because its product name sounds like the system topology.

Some projects have two ledgers. A hospital battery can reduce demand charges every day and carry critical load during an outage. In that case, choose the product that handles the harder ledger with less manual work. Document the secondary ledger as a validation case.

The framework also exposes projects that need more than one model. The HOMER Pro vs PVsyst comparison explains why dispatch optimization and detailed PV yield answer different questions. The C&I BESS sizing guide covers the power and energy inputs that must agree with the dispatch case.

Inputs that decide whether the model is useful

Software selection matters less than input control once the correct product is open. A perfect tariff engine cannot repair a monthly load total masquerading as an interval profile. A detailed generator model cannot repair fuel prices that nobody checked.

For tariff-led work, assemble the utility record first. Collect interval load data, recent bills, the tariff identifier, effective date, riders, contracted demand, export rules, and power-factor treatment. Reproduce at least one known bill before adding solar or storage. The Energy Toolbase glossary provides context for another tariff-led platform, but this article does not claim the products are interchangeable.

For architecture-led work, build an asset input register. Record each resource, candidate size, capital cost, replacement assumption, operating limit, fuel curve, maintenance condition, and controller rule. Separate measured inputs from vendor data and project assumptions. Then vary the assumptions that could reverse the chosen architecture.

Input group	Minimum evidence	Failure it prevents
Electrical load	Interval data with timezone and missing-data review	Battery sized against the wrong peak or duration
Utility tariff	Current tariff plus a real bill	Savings based on an obsolete or incomplete rate
Solar resource	Named dataset and site coordinates	Resource copied from the wrong location
Battery	Power, energy, efficiency, state-of-charge limits, replacement basis	A battery that meets energy but misses power
Generator	Fuel curve, minimum loading, fuel price, maintenance assumption	Unrealistic generator runtime and cost
Outage case	Critical-load schedule and stated outage assumption	Backup claim that has no operating definition
Financial inputs	Source, date, currency, and decision owner	A model that cannot be audited later

The model review package

A project model needs a review package that another engineer can reopen without guessing. The software file is one item in that package. Input provenance, scenario controls, and result interpretation make the file auditable.

Start with a one-page model basis. Name the decision, product, software version, model owner, review date, currency, project term, and approval metric. Then list the scenario that controls the recommendation. A result called final tells the reviewer nothing about the conditions inside it.

The package should contain these items:

• Original interval-load file and a cleaned copy with every change logged.
• Utility tariff document, effective date, account class, and bill-reconciliation note.
• Resource data with provider, coordinates, period, and file name.
• Component inputs with source documents and observation dates.
• Assumption register with owner, rationale, and sensitivity treatment.
• Scenario index that explains each case and identifies the recommended one.
• Exported results for economics, energy balance, dispatch, and outages.
• Reviewer comments plus a record of model changes made in response.

Keep three labels distinct. Measured means the value came from the site, meter, bill, or verified data file. Vendor-stated means a manufacturer or software publisher supplied it. Assumed means the project team chose it for analysis. A model can use all three, but the report should not blend them.

Review question	Evidence in the package	Reject the model when
Does the baseline match reality?	Bill reconciliation or fuel-use comparison	The base case is materially unexplained
Can the input be traced?	Source, date, units, and file reference	A load, tariff, cost, or limit has no owner
Could another case win?	Sensitivity results around decisive assumptions	The recommendation survives only one narrow case
Does the equipment fit?	Datasheets and operating limits	Generic components hide real limits
Does the outage case mean anything?	Critical-load schedule and control assumption	Backup duration lacks an operating definition
Can the design team use the result?	Selected capacities and handoff constraints	The report stops at charts and has no design basis

Version the package when a decisive input changes. A new tariff, equipment quote, load file, or project schedule can reverse the result. Do not overwrite the approved model and leave its old report in circulation. Freeze the prior version, state the reason for change, and issue a new recommendation.

What neither product replaces

Neither HOMER Grid nor HOMER Pro turns an optimized capacity into a construction package. The model can support an investment and sizing decision. It does not place modules around roof obstructions, resolve a string layout, prepare a single-line diagram, or issue structural and electrical drawings.

This boundary affects commercial risk. A model may select a PV capacity that the usable roof cannot hold. A dispatch case may assume a battery inverter rating that conflicts with available equipment. A resilience case may omit the transfer scheme and protection coordination needed for island operation.

The handoff should move through five checks:

1. Confirm the model’s selected PV, battery, generator, and grid capacities.
2. Test physical fit using surveyed geometry and equipment clearances.
3. Replace generic production inputs with a site-specific solar yield.
4. Develop the electrical topology, protection approach, and control narrative.
5. Feed material design constraints back into the optimization model.

That last step is easy to skip. The optimization output looks finished because it contains money, capacities, and charts. Detailed engineering often changes one of those inputs. The model should be rerun before the proposal becomes a procurement commitment.

How Heaven Designs helps after the software decision

Heaven Designs does not sell HOMER Grid or HOMER Pro. The useful role begins around the model boundary: collecting defensible site inputs, testing the physical PV concept, and converting an approved capacity into engineering deliverables.

• Site survey and land feasibility supports the geometry, site constraints, and resource inputs that the early model cannot prove on its own.
• Solar 3D pre-design tests whether the proposed PV capacity fits the available site and identifies shading constraints before detailed engineering.
• Rooftop detailed engineering develops the selected concept into layouts, single-line diagrams, structural work, bills of quantities, and related execution drawings.

If the model already exists, send the assumptions, selected capacities, load data, and site information through the project contact form. The team can scope the downstream design work without pretending the optimization report is a construction set.

FAQ

Is HOMER Grid better than HOMER Pro for commercial solar and storage?

HOMER Grid is usually the cleaner start when demand charges, time-of-use savings, EV charging, or a customer proposal drive value. HOMER Pro may fit better when generators, several resources, custom controls, or broad sensitivity work dominate. The commercial label alone does not decide.

Can HOMER Pro model utility tariffs and demand charges?

Yes. HOMER Pro includes basic grid-rate inputs. Its Advanced Grid module adds scheduled and real-time rates, demand charges, peak shaving, grid extension, and outage modeling. HOMER Grid places tariff work closer to the main workflow, so it may require less setup for a tariff-led C&I study.

Can HOMER Grid model an outage or islanded operation?

Yes. The HOMER Grid resilience manual separates critical from non-critical load and supports specified or random multi-day utility outages. The model can also account for advance outage knowledge. The result still depends on an approved critical-load schedule, control assumptions, and equipment that can perform the intended islanding function.

Which product should an Indian C&I developer choose?

Choose from the decision, not the country. A tariff-led behind-the-meter solar and storage study may fit HOMER Grid. UL Solutions limits its built-in coverage claim to the United States, Canada, and Mexico. An Indian tariff therefore needs careful custom setup and bill validation. Generator-led microgrid work may fit HOMER Pro better.

Does either product replace PVsyst or detailed design software?

No. HOMER products address system configuration, dispatch, tariffs, resilience, and economics. Detailed PV yield, site geometry, string design, electrical drawings, and structural drawings are separate tasks. Hybrid teams may use a HOMER product for architecture and economics, then use PV yield and engineering tools for the buildable design.

How often should HOMER pricing be checked?

Check pricing when procurement starts and again before approval. This article records official commercial prices observed on September 26, 2026. License tiers, modules, training, regional terms, and enterprise discounts can change. Keep the official source URL and observation date in the purchase record.

Should a project team ever use both HOMER Grid and HOMER Pro?

Sometimes, but two licenses should solve two real review problems. A complex C&I microgrid may use Pro for resource architecture and Grid for tariff or proposal work. First test whether Pro with Advanced Grid or Grid with resilience covers the whole case. Duplicate models add reconciliation work and can drift apart.

The clean decision is the one another engineer can reconstruct. Name the ledger, preserve the source data, state the software version, and keep the downstream engineering boundary visible.