Off-grid & Remote — HOMER Pro
Reliable, affordable power for communities beyond the grid
HOMER Pro is the global standard for designing least-cost hybrid microgrids—helping remote communities and island utilities break free from diesel dependency while ensuring 24/7 power reliability.
The diesel trap: why remote communities pay the highest energy prices on earth
Hundreds of isolated communities worldwide—from Pacific islands to Arctic villages to Sub-Saharan settlements—depend entirely on diesel generators for electricity. They face energy costs of $0.40 to $1.50 per kWh (vs. $0.10–$0.15 on mainland grids), volatile fuel prices, fragile supply chains, frequent outages, and growing environmental pressure. The good news: hybrid renewable microgrids can slash these costs by 35–70% while dramatically improving reliability.
Critical pain points
Why diesel-only systems fail communities
Crippling fuel costs
Diesel delivered to remote sites can cost 2–10x mainland prices. Many communities spend 30–40% of their entire budget on electricity alone.
Fragile supply chains
Fuel must be shipped, trucked on seasonal ice roads, or even flown in. A single supply disruption can leave communities without power for weeks.
Unreliable power
Aging diesel generators fail frequently. Some island communities experience weekly outages, limiting economic development and endangering health services.
Carbon & environmental risk
Diesel spills threaten fragile ecosystems. Communities face growing pressure from funders and governments to decarbonise, but lack the tools to plan the transition.
From diesel dependence to energy independence—modeled and optimized
HOMER Pro was originally developed at the U.S. National Renewable Energy Laboratory specifically for this challenge: finding the optimal combination of renewable and conventional generation for off-grid systems. Today, over 250,000 energy professionals in 190+ countries rely on HOMER to design microgrids that deliver reliable, affordable power to communities of every size.
Core modeling advantages
Built for confident decisions
Simulation
Model your exact community load profile with solar, wind, diesel, hydro, biomass, and battery storage—simulating every hour of the year to ensure the system works in all seasons and weather.
Optimization
HOMER examines thousands of system combinations automatically to find the least-cost design that meets your reliability requirements. No manual trial-and-error needed.
Sensitivity Analysis
Test "what if" scenarios: What if diesel prices spike 50%? What if load grows 3% per year? What if a cyclone season reduces solar output? See how your optimal design changes under uncertainty.
Additional Capabilities
- +Hydro module: Model stream-flow hydro resources for island and mountain communities with seasonal rivers.
- +Biomass module: Add biogas or biomass gasification for communities with agricultural waste.
- +Multi-Year module: Project long-term system performance accounting for load growth, PV degradation, and fuel price escalation.
- +Advanced Storage: Model battery degradation realistically in tropical heat or Arctic cold using the Modified Kinetic Battery Model.
Use Case: Replacing diesel on a Pacific island
The Situation
A 2,500-person island community in the Pacific relies on aging diesel generators for all its electricity—paying over $0.90/kWh and experiencing weekly outages. Fuel is delivered by barge every 6–8 weeks, and a single delayed shipment risks days without power for the hospital, schools, and water pumping stations. The island government has secured funding from an international development bank to transition to renewable energy, but needs a bankable feasibility study to unlock the investment.
What Was Modeled
Using HOMER Pro, engineers modeled the island's hourly load profile across all 12 months, incorporating seasonal variation. They evaluated hundreds of system configurations combining rooftop and ground-mount solar PV (200–800 kW), a 275 kW wind turbine, lithium-ion battery storage (500–2,000 kWh), and the existing 3 x 400 kW diesel generators as backup. The Hydro module evaluated a small 50 kW run-of-river installation. Sensitivity analysis tested diesel price volatility and a 2% annual load growth rate over 25 years.
The Outcome
HOMER Pro identified the optimal system: 600 kW solar PV + 275 kW wind + 1,200 kWh battery + 2 existing diesel generators (1 decommissioned). This configuration achieves 85% renewable penetration, reduces LCOE from $0.90/kWh to $0.34/kWh, cuts CO2 emissions by 75%, and reduces diesel consumption by over 200,000 liters per year. The bankable report generated from HOMER's output satisfied the development bank's due diligence, unlocking a $4.2M investment.
Real-World Applications
| Location / Client | Project Type | Key Result |
|---|---|---|
| Shungnak, Alaska | Arctic village hybrid microgrid replacing diesel with solar + storage | Significant reduction in energy costs and greenhouse gas emissions |
| Harbledown Island, BC, Canada | First Nations community microgrid modeled with HOMER Pro | Reduced noise, air pollution, and energy costs after one year |
| Kea Island, Greece | Autonomous PV + diesel + battery microgrid for residential network | Least-cost design achieving 25%+ renewable penetration |
| Gilutongan Island, Philippines | Solar-diesel hybrid replacing 4.5-hour/day diesel service | 24-hour power, LCOE cut from $1.21 to $0.36/kWh (70% reduction) |
Recommended HOMER Products
HOMER Pro
Self-sufficiency and resilience
The global standard for off-grid and microgrid design. Models every combination of solar, wind, diesel, hydro, biomass, and batteries to find the least-cost system that keeps your community powered 24/7.
Key Modules: Hydro, Biomass, Multi-Year, Advanced Storage, MATLAB Link
Supporting Services
Advisory Services
UL Solutions advisory services enable you to leverage long-standing expertise in renewable energy. We offer full project support from feasibility studies to design and certification.
Learn More →Engineer Hours
Put a UL Solutions expert on your team by hiring a HOMER specialist by the hour. Perfect for community energy planners who need expert guidance on their first HOMER model.
Learn More →Ready to design affordable, reliable power for your community?
Whether you're electrifying a remote village for the first time or transitioning an island utility away from diesel, HOMER Pro gives you the techno-economic analysis to make confident decisions and secure funding.