HOMER Pro

HOMER Pro® is a software platform for designing and optimizing hybrid microgrid and distributed energy systems. Developed initially at the National Renewable Energy Laboratory (NREL) and currently distributed by UL Solutions, it models combinations of renewable energy sources, conventional generators, energy storage, and grid connections. The software evaluates technical feasibility and economic viability by simulating system operations over time, identifying cost-optimal configurations based on user-defined constraints and sensitivity variables. It serves sectors including remote off-grid communities, grid-connected campuses, military bases, and island utilities.

HOMER Pro simulates system performance at granular time intervals (1 minute to 1 hour) over one year. It calculates energy balances by comparing supply from components (e.g., solar panels, wind turbines, generators) against demand in each interval. For systems with batteries or generators, it determines operational strategies such as charging/discharging cycles or generator dispatch. The engine assesses feasibility by verifying if configurations meet demand reliably and estimates costs—including capital, replacement, fuel, maintenance, and financing—over the project’s lifetime.

Two algorithms drive optimization:

Grid Search: Simulates all feasible system configurations defined by user inputs.

HOMER Optimizer™: A proprietary derivative-free algorithm that identifies cost-optimal solutions without exhaustive simulation.

Both rank configurations by net present cost (NPC), enabling direct comparison of economic performance.

Users test uncertainties (e.g., fuel price fluctuations, wind-speed variations) by assigning ranges to sensitivity variables. The software reruns optimizations across these ranges, revealing how changes impact system design and economics. This feature supports risk assessment and scenario planning.

The base software supports core components including solar photovoltaic (PV) systems, wind turbines, battery storage, diesel generators, and basic grid interconnection modeling. To address specialized energy scenarios, HOMER Pro offers modular extensions that integrate seamlessly with its simulation environment. These modules enable granular analysis of niche technologies while maintaining the software's core optimization framework.

• Biomass Integration: Simulates biomass gasification processes and biogas-fueled generator operations, accounting for feedstock variability and conversion efficiency.
• Hydro Resource Analysis: Incorporates stream-flow dynamics for micro-hydropower systems, evaluating seasonal water availability and turbine performance.
• Combined Heat and Power (CHP): Models thermodynamic interactions between boilers, heat recovery units, and thermal loads to optimize cogeneration efficiency.
• Advanced Load Profiling: Distinguishes between AC/DC electrical demands and manages deferrable loads (e.g., HVAC cycling, agricultural pumping) for demand-shifting strategies.
• Hydrogen Systems: Tracks hydrogen production via electrolysis, storage in pressurized tanks, and electricity generation through fuel cells.
• Temporal Dynamics: Projects long-term system behavior via the Multi-Year module, factoring in component degradation, load growth patterns, and fuel price escalation curves.

Users activate modules through license keys, extending HOMER Pro's native libraries. Each module introduces component-specific input parameters—such as biomass feedstock calorific values or hydropower head height—while maintaining interoperability with core optimization algorithms. Results are aggregated in unified outputs, allowing comparative analysis between hybrid configurations with and without specialized technologies. This modular architecture ensures scalability from basic renewable systems to complex polygeneration microgrids.

HOMER (Hybrid Optimization Model for Multiple Energy Resources) originated at NREL to address remote power challenges. UL Solutions later enhanced it for commercial use. The software’s evolution reflects growing demand for tools that integrate renewables with conventional generation while balancing reliability and cost .

Users input component specifications, costs, resource data (e.g., solar irradiance), and load profiles. After simulations, results display as sortable NPC rankings alongside technical metrics (e.g., renewable fraction, emissions). Tables and graphs facilitate cross-configuration comparisons, aiding reporting and decision-making.

• Off-grid systems: Designing cost-effective solutions for remote areas.
• Grid resilience: Enhancing reliability for critical facilities like hospitals.
• Academic research: Analyzing energy transitions in university microgrid projects