VRB Power Systems Inc. in conjunction with the National Renewable Energy Laboratory (NREL) has completed the addition of a Flow Battery module to NREL's HOMER software suite. HOMER, The Micropower Optimization Model, is one of the world's most powerful (and most widely used) micropower design models. HOMER simulates and optimizes stand-alone and grid-connected power systems comprising any combination of wind turbines, PV arrays, run-of-river hydro power, biomass power, internal combustion engine generators, microturbines, fuel cells, batteries, and hydrogen storage, serving both electric and thermal loads. The HOMER output includes a range of recommended technology combinations, and provides an economic and technical assessment of each, including the quantity of air emissions avoided.
HOMER can be freely downloaded from www.nrel.gov/homer. The flow battery is currently available in a beta version from the website, and will become a permanent feature of the HOMER software when HOMER version 2.2 is publicly released.
The National Renewable Energy Laboratory (NREL) is the nation's primary laboratory for renewable energy and energy efficiency R&D. Established in 1974, NREL began operating in 1977 as the Solar Energy Research Institute. It was designated a national laboratory of the U.S. Department of Energy (DOE) in September 1991 and its name changed to NREL.
In this sample output (below), an existing system consisting of three 1500 kW diesel generators is modeled. The colored regions on the map indicate the conditions under which various combinations of wind generation and flow battery storage can enhance the existing plant's operation. For example, at the current diesel price, $0.80/liter, a wind generator can be justified if average wind speeds of 4 m/s are present, and the optimal system will include 400 kWh of flow battery storage. At average wind speeds of 5 m/s, 3200 kWh of flow battery storage are optimal. The map also clearly shows that at current fuel costs and in moderate wind regimes, flow battery storage is an economic and necessary component for all wind plant additions.
White Papers & Case Studies
The following documents are in PDF format. To view a file, you must have Adobe Acrobat Reader which is a freeware PDF viewer. If you don't have it, download Acrobat Reader here.
- VRB-ESS - RAPS-Diesel Application - (PDF document)
- RAPS Brochure - (PDF document)
