Energy Modeling for Dummies: A Review of the HOMER Energy Modeling Sofware

I’m not an engineer, but if renewable energy is going to really take off, a lot of non-engineers are going to need to answer the basic question when considering an alternative energy system, specifically: Which energy technology or mix is best for THIS unique project under MY unique environmental and economic conditions?
The HOMER energy modeling tool developed by the National Renewable Energy Labs and now distributed through HOMER Energy LLC out of Boulder, CO can be a big help in providing a fairly robust estimate on the financial, technical, and environmental costs of installing a renewable energy system tailored to a project’s unique circumstances and location. To use the program you input the environmental conditions; and the technologies and conditions that you want it to consider and it models the viability of the different options.

Pros

• It’s free (enough): The full version is free for 14 days, and costs $99 after that, but odds are you don’t really need that unless you’re a hardcore energy modeler already. Go for the free beta version. There are also free downloadable examples for several types of models (i.e. an off-grid house in Texas) so you don’t have to start from scratch.
• Scalable: It doesn’t matter if you want to model a solar panel for a single light bulb, or model a grid for of 250,000 people considering six energy technologies, Homer can handle it. I used it to model a complete energy grid for Marinduque Island in the Philippines considering several biofuels blends, and wind- hybird, and geothermal systems (wind hybrid was the most economical, but a biofuel blend had the most potential for social and environmental sustainability).
• Flexible parameters:  If you have the data, you can tweak just about every financial or technical perimeter imaginable whether it’s the carbon density of a biodiesel input, of the discount rate over 25 years. For example you can compare the effectiveness of a Vestas V82 wind turbine to a Furhlander 30 at low speeds.
•  Lightweight: The program itself can download in about a minute and you won’t need a supercomputer to run the simulations.  About 10 minutes on a core i5 laptop is the norm.
• Meaningful outputs: Graphs and charts are easy to read, meaningful and exportable.
• Environmental data links: Reliable wind and solar data can imported seamlessly from external sources.

Cons

• Steep learning curve: Designing a project from scratch is intimidating to non–engineers, fairly complicated concepts like defining how many batteries are on a string, can be difficult. All other weaknesses are related to this basic problem of dumbing down engineering details.
• No wizards: I’m usually not a fan of wizards, but in this case it would be very helpful, given the complexity of the problem.
• Lack to input data: You need quite a lot of input data to even get started. It would be nice if somehow HOMER could link you to other sites or databases to get reliable cost information. For example you could click on a battery type and the costs could automatically be entered.

Currently, Homer is geared towards professional renewable energy engineers, and as such it’s a flexible and powerful modeling tool; but because easily accessible, free, and able to run on a PC, it has proven to be an invaluable tool for students and researchers, who can learn holistically, and practically, how to design energy system without breaking the bank. However, because of its complexity and lack of a wizard to get started, it remains too complicated for the layman on their own to answer the basic question for renewables: which technology is best for THIS project under MY specific conditions?