Thursday, October 31, 2013

Happy Halloween DOD: Great Microgrid Primer from the SPIDERS team


DOD's Smart Power Infrastructure Demonstration for Energy Reliability and Security (SPIDERS microgrid program) prime integrator Burns & McDonnell has produced an outstanding white paper for anyone wanting to better understand the why's and how's of microgrids.

Overall it's a great paper, but two parts jumped out at me immediately for their value to decision makers.  Here you go, the first is from a section on mission drivers:
By allowing multiple generation assets to provide power for a common load, microgrids greatly increase both the reliability of power and its efficiency of generation. Typically, the greatest beneficiaries of microgrids are customers with large, mission critical facilities or large power consumers in areas prone to frequent and/or prolonged outages (e.g. hurricane zones). Although facilities like these have utilized on site generation in the past, they are starting to migrate towards microgrids due to the many examples of single generators failing during prolonged outages thereby leaving the entire mission in jeopardy.
Unless you absolutely have no choice, you never want to bet the farm on a single generator, but until now there's been little choice. SPIDERS has gone from an aspiration in the minds of the Defense Science Board (2001, 2008) to reality in 2013. See these before and after results reported by Burns:
Prior to SPIDERS, critical loads were individually served by isolated generators which were oversized for the normal load, and thus ran inefficiently. Also, renewable energy assets such as PV arrays were of no value upon loss of utility power. When connected to the microgrid, generators are decoupled from their individual loads allowing a single generator to serve multiple loads and allowing the PV to support the loads. Under operation of the SPIDERS microgrid, critical loads were served continuously during
a 3‐day simulated power outage and testing indicated that the system served the loads using 30% less diesel fuel by operating fewer generators at more efficient points and by integrating renewables into the power island. 
Think: Nellis AFB's 14.1 MW solar installation, an Air Force renewables showcase, that's of exactly zero use if/when the local power fails. It's only wired to shoot electrons into the off-base grid. 

My 2 centavos: All DOD renewables should be deployed in microgrid configurations from now on.  It should become the rule, not the exception.

You can (and should) read the full paper (HERE).

Photo credit: Matt from Somerville on Flickr.com