12:26pm

Fri September 28, 2012
Micro-Grids

Energy for the future: Micro-grids explained

They’re being touted as the future in local energy distribution: a way to save money, reduce our carbon footprint, and jumpstart local economies. But what exactly are micro-grids*?

Put simply, micro-grids are small-scale, localized versions of the centralized electricity system that allow integration of both renewable and traditional energy sources.

While they generate, distribute and regulate electricity flow at a local level, micro-grids are still connected to the greater electricity grid.

Micro-grids have been developed to service universities, military bases, offices, or communities.

For example, Princeton and Harvard Universities both own and operate their own micro-grids, and this gives them the freedom to diversify their source of power either partially or completely.

Micro-grids also enable consumers to meet some, or all, of their energy needs through the generation and use of their own power sources. This can include solar, wind, geothermal and other sorts of renewable energy.

Reliable and cost effective

Micro-grids are connected to the larger electrical grid, but have the ability to disengage from the main grid and operate independently.

In the event of a power outage in the main grid, micro-grids can simply cut their connection and continue to function normally on a local level.

According to the Galvin Electricity Initiative, this single function has the ability to save communities a lot of money.

The Initiative’s website states that:

Consumers and businesses in the U.S. pay at least $150 billion per year in costs due to power outages.

However, Harvard University released an abstract in 2007 which stated that when micro-grids are disconnected and running under “islanding conditions” (e.g. without the backup of the main grid) there can be problems with frequency and voltage fluctuation.

This abstract was for a proposal to research a method that would stabilize this inherent feature of the technology, and a similar project was released earlier this year to improve on previous developments.

Micro-grids in New York state

In September 2010, New York state did a study into the benefits, opportunities, and barriers to putting more Micro-grid technology into the region.

The study found that direct economic benefits potentially created by micro-grids could be far reaching, and that they would allow greater use of renewable energy.

U.S army engineers are researching tactica micro-grids to get more efficient energy to soldiers.
Credit Some rights reserved by RDECOM

Japan and Denmark are leading the world in this technology, and while there are several micro-grid projects currently in the U.S, there are policy barriers to introducing the technology here.

The New York state study in 2010 presented the legal and policy issues in deploying micro-grids in the following way:

Many potential projects would be unable to bear the administrative burden of full regulatory treatment as a distribution utility under State law. In tandem, the lack of legal identity and regulatory certainty presents a variety of obstacles for investors, utility customers and engineers considering these types of projects. These obstacles are problematic because the installation of such facilities has the potential to reduce costs to customers and to further public policy by improving the reliability and efficiency of power sources.

Micro-grids have been shown to be efficient in not only reducing the cost for consumers, but also in reducing carbon footprints.

The Galvin Electricity Initiative says on their website:

The most significant environmental benefit of a smart micro-grid is its ability to use local generation and the resulting ‘waste’ heat to displace coal-fired generation.

This form of energy distribution also allows consuming businesses and populations to be better placed for known and unknown needs in the future.

Micro-grids are certainly a long way away from being a part of every town, university and business in the U.S., but they provide technology which could potentially benefit communities exponentially.

*Micro-grids or microgrids? It's about like the cyber-security/cybersecurity thing. Both the hyphenated and the non-hyphenated versions seem to be in circulation. We've come down on the side of the hyphen. Editor