Solar Power International 2015 Pre-Event Showcase - Page 8

energy storage FEATURE

Written and influenced by Eric Hill, Strategic Platforms Manager, Alpha Technologies, Inc.

Mark Mays, Senior Applications Engineer and Mark Cerasuolo, Director of Marketing and Training, both from OutBack Power Technologies, Inc.

Energy Storage eFeature |January 2015

Solar plus Storage:

Renewable energy production and the means to harvest it are being reunited. We cover the essentials.

Solar electricity is celebrating the 60th anniversary of its birth at Bell Laboratories in 1954. From its first practical application—powering the Telstar communications satellite along with all of Telstar’s descendants—solar electricity has traveled with a way to store it, as the means to achieve independence from the sun’s variable availability in Earth’s orbit, where day becomes night every 90 or so minutes depending on the mission.

Even before Telstar, NASA’s space pioneers recognized the need for integrating solar electricity with storage. The first solar-powered satellite, Vanguard I, was designed to stay active for seven years using solar-augmented batteries - well past the 20 day lifespan possible then with battery powered transmitters. While the space program, the first and most famous application for PV/solar, represented a hallmark technological achievement of the developed world, the growth of solar electricity back on Earth diverged down two paths marked by two very different sets of needs.

Back on Earth

The developed and relatively urbanized world could take a luxury approach to solar electricity and use the technology to offset the use of fossil fuels, and to achieve reasonable system economics that favored the widespread installation of grid-direct or grid-tie systems without any storage capability. However, the developing and more remote world was not looking at solar to replace other forms of electrical generation, but rather as a potential means to produce electricity in off-the-grid situations where centrally-generated utility power was either weak or nonexistent.

The second scenario is what gave rise to the “microgrid” concept: essentially an all-in-one system comprised of power conversion of a renewable source or sources (solar, wind, hydro) possibly augmented with a generator for when those sources are inadequate, as well as energy storage, management and control sub-systems, for supplying electricity at the very local level. A small fishing village in South America, a forward military operating base in South Asia, or a remote vacation resort in Canada might all have microgrid electricity supply as their common denominator despite their substantial differences in geography and purpose.

A battery storage project at the Santa Rita County Jail in California.