Distributed Energy Storage, Microgrids and the "Enernet"

Distributed energy storage is a term for warehousing energy closer to where it is consumed.  Storage can be electric vehicle batteries, flywheels, thermal like molten-salt batteries, among several technologies being explored.  At the very least, DES can compensate for variations typical of renewable sources like wind and solar that are susceptible to moving clouds and changing windspeeds and directions. It can also assist with brief service interruptions as a "UPS" or backup power for entire facilities or at least its more critical loads. DES can be a part of a net-zero or net-positive energy plan for a facility (in California, for example, buildings will need to be self-sufficient by 2030).

Essentially, distributed energy generation and storage can combine to create not only self-sufficient buildings, but an entire campus or communities. These power islands, or microgrids, can run completely isolated from the convensional grid, or they may have bridges that allow it to interconnect at designated times. A grid composed of generally-independent microgrids, a power internet or "enernet," would minimize the specter of regional blackouts and encourage greater integration of renewables. Advantages include fewer line losses (energy wasted as heat or unused magnetic fields), a lower demand on transmission infrastructure, reduced need for new generation, and the ability to rely on more localized sources of power generation. University, military, hospital, and other segments are increasing adoption of this paradigm.

Utilizing the flexible and cost-effective Power Analytics Corporation (formerly EDSA) platform and a number of distributed power sources, including a fuel cell generation from wastewater treatment plant's methane, University of California at San Diego developed a microgrid that has garnered much attention. 

When considering power islands, actual islands come to mind. The island of Alcatraz, for instance, has developed a microgrid that has improved its reliability and sustainability, particularly poignant as islands are most at risk from the rising sea levels. 

Kaiser Permanente hospitals, Apple, AT&T nd others have turned to Bloom Energy for on-site power generation that utilizes fuel cells that efficiently convert a fuel like natural gas into DC and AC with minimal carbon emissions.  With enough generation, it is possible to use the power grid as a backup for maintenance or trouble with the gas supply or Bloom's "power servers."

As microgrids gain momentum, the international professional body of electrical engineers (IEEE), continues to develop standards to aide this important development toward a smarter grid.  Denmark stands out as a leader in the development of microgrids and the integration of non-utility distributed generation and demand response through in-home display technology, but the developing world may have the most to gain.