Software helps determine hybrid energy sources

By Laura Carrabine, Senior Editor

HOMER energy modeling software is used to design and analyze hybrid power systems that contain a mix of conventional generators, cogeneration, wind turbines, solar photovoltaics, hydropower, batteries, fuel cells, hydropower, biomass, and other inputs.

For either grid-tied or off-grid environments, the software helps determine how variable resources such as wind and solar can be best integrated into hybrid systems. Engineers and non-professionals use the product to run simulations of different energy systems and compare the results to obtain a realistic projection of their capital and operating expenses. HOMER determines the economic feasibility of a hybrid energy system, optimizes the system design, and helps you understand how hybrid renewable systems work.


Here is a graph of the annual solar resource for the city of San Diego. It demonstrates how HOMER obtains solar resource data for users and helps them evaluate the data.

As distributed generation and renewable power segments continue to grow, the software can serve utilities, telecoms, systems integrators, and other types of project developers – to mitigate the financial risk of their hybrid power projects.

The product’s optimization and sensitivity analysis algorithms help you evaluate the economic and technical feasibility of a number of options and to account for variations in technology costs and energy resource availability.

For a village or community-scale power system, HOMER can model the technical and economic factors involved in the project. For larger systems, the product can provide an overview that compares the cost and feasibility of different configurations.

For instance, HOMER Energy, the outfit that develops the software, will soon work with the City of San Diego and the California Center for Sustainable Energy to develop an energy independent micro-grid at a community recreation center that will serve as a command center for fire and rescue teams. By integrating distributed generation into its emergency infrastructure, San Diego will be able to enhance energy security and improve its crisis response capabilities. The center will be able to function off the grid for up to 48 hours in the event of an emergency.


HOMER identifies the least cost system configuration as a function of many parameters. This figure shows how the least cost system price and annual average windspeed for a village in the Philippines.

Working under joint funding from the Department of Energy’s Solar America Cities Program and the California Public Utilities Commission’s Self-Generation Incentive Program (SGIP), San Diego will create an independent micro-grid at the Scripps Ranch Community Recreation Center by installing photovoltaic systems and advanced energy storage (AES). HOMER Energy is analyzing alternative micro-grid power system configurations to meet the site loads, including emergency response equipment. HOMER software is used to identify the most cost-effective combination of PV and battery storage that meets the system design goals, while working within funding and site constraints.

Aside from its quest for a reliable, secure, decentralized, and resilient energy supply, the City of San Diego anticipates that energy independent centers will save money during normal operation, by generating electricity with renewable energy, and by using advanced energy storage systems to reduce demand charges and on-peak energy charges by shifting electric loads. California is the first state to grant incentives for advanced energy storage – a relatively new technology – along with the normal incentives for renewable energy technologies.

HOMER Energy