Sustainable Power Systems


Sustainable Power Systems is a leading microgrid design and integration firm based in Boulder, Colorado. Our vision is a world powered largely by distributed generators, most of which will use clean renewable energy sources. Microgrids are an early manifestation of this energy revolution.

By definition, a microgrid must be capable of operating in “islanded” mode, independent from a central utility. Remote (off-grid) microgrids, such as those serving islands and remote villages, operate islanded all of the time. Grid-tied microgrids operate islanded in response to a utility outage, or to take advantage of a financial incentive to voluntarily and temporarily disconnect from the utility. Islanded operation becomes particularly challenging when a microgrid includes a lot of wind and/or solar generating capacity, because the highly variable and intermittent nature of renewable resources can make it difficult to provide stable, reliable, and well-regulated power. Sustainable Power Systems specializes in high renewables fraction microgrids, where typically over 50% of the load is met with clean renewable energy. Moreover, the majority of our microgrid experience is in remote villages and on islands, where there is no central electric utility. This experience has made us experts at designing systems that provide stable power whether or not they are operating grid-connected.

Our founder and director, Steve Drouilhet, has been a HOMER user since the 1990s, when he was a Senior Engineer at the National Renewable Energy Laboratory developing high-penetration wind-diesel hybrid power systems. HOMER is a wonderful modeling tool, but it takes considerable experience and engineering insight to turn a HOMER-optimized conceptual design into a feasible, stable, and reliable power system. We invite HOMER users to contact us with the details of their application and work with us to achieve a microgrid system that meets their needs, goals, and budget.