Power from the Sun: Achieving Energy Independence
By Dan Chiras, with Robert Aram and Kurt Nelson
257 pp. New Society Publishers – Aug. 2009. $26.95.
For the average home- or small business-owner looking to purchase a solar PV array, there is much homework to be done—and truly good textbooks, amid the cacophony of voices on the subject, are a real find. Thankfully, Power from the Sun, the latest offering from green building guru Dan Chiras, is just such a book.
In eminently readable, informative, accessible prose, Power from the Sun describes the components and workings of a solar electric system, how to go about having one installed and some basic things to know in order to be an informed consumer and avoid common pitfalls. Solar PV buyers will still have a bit of legwork to do after reading the book, including finding local solar contractors and obtaining quotes. But once these steps are done, their learning curve will no doubt be greatly reduced.
Power from the Sun is wonderfully exhaustive. It begins with an overview of solar electric systems, their applications and pros and cons. Then it takes readers through a primer on the Sun and solar energy, introducing such key concepts as irradiance, irradiation and direct/diffuse radiation, among others that are crucial to understanding how solar electric systems work. One particularly entertaining aside is Chiras’ brief history of the invention and gradual refinement of solar cells beginning in 1839—with the discovery, by one French scientist, that two brass plates submerged in a conductive liquid, and shone on by a light, will produce an electrical current.
Following these initial background chapters, the remainder of the book is devoted to practical advice for those looking to implement a PV energy project. Chiras emphasizes repeatedly that the first step should always be to calculate one’s total electrical consumption and then look at ways to reduce it through efficiency improvements. This is because solar PV systems are still very expensive, and simple efficiency measures can save thousands of dollars by allowing one to purchase a smaller system than would otherwise be necessary. To this end, the book is filled with helpful charts, tables and legends to be used in determining the electrical consumption of one’s residence or small business.
Chiras points out that although by far the most popular solar electric system is the batteryless grid-connected type, different people may want to look at other options depending on their needs. So he spends a section detailing all four types of systems (batteryless grid-connected, grid-tied with a battery backup, off-grid and hybrid) and some things to think about when trying to select one.
The present reviewer is hardly within his depth in trying to sum up the sections on batteries, charge controllers and gen-sets; how to mount an array for maximum output; and understanding inverters. But suffice it to say that Chiras certainly succeeds in his attempt to make these complex technical concepts understandable to the general reader. He states in the book’s introduction that “you won’t need a degree in electrical engineering or physics to understand this material”—and, truly, you don’t.
Over the past three decades, Chiras has pulled off the amazing feat of both fashioning a sustainable life for himself—he lives in a natural home run entirely on solar and wind, and built from straw bales and rammed earth tires—and drawing on this firsthand experience in churning out a formidable oeuvre of books on sustainability and natural building. He also serves as director of The Evergreen Institute’s Center for Renewable Energy and Green Building, which offers certificates in residential renewable energy and green building.* In short, it’s hard to imagine a more credible guide than Chiras to walk us through this introduction to solar PV systems.
His two coauthors on this book are Robert Aram, an electrical engineer and longtime renewable energy advocate and consultant; and Kurt Nelson, a seasoned solar PV installer whose company SOLutions specializes in the design, consultation, sales, installation and service of off-grid systems.** Together these three authorities have created a detailed, comprehensive, easy-to-understand guidebook that is sure to be read thirstily, and with great profit, by anyone intent on purchasing a PV system.
* Bio information gathered from: “Renewable Energy for Homeowners with Dan Chiras, Ph.D.,” The VoiceAmerica™ Talk Radio Network, Jan. 13, 2009, http://www.modavox.com/voiceAmerica/vepisode.aspx?aid=35677 (accessed Oct. 19, 2009); Home page for The Evergreen Institute: Center for Renewable Energy and Green Building, http://www.evergreeninstitute.org/ (accessed Oct. 19, 2009); “Cost of Natural Building,” Green Home Building, http://www.greenhomebuilding.com/QandA/natural/cost.htm (accessed Oct. 19, 2009).
** Dan Chiras, “Preface,” in Dan Chiras, Mick Sagrillo, and Ian Woofenden, Power From the Wind: Achieving Energy Independence (p. XII), (Gabriola Island, BC, Canada: New Society Publishers, 2009); “Power from the Sun: A Practical Guide to Solar Electricity,” Federal Publications Inc., http://www.fedpubs.com/subject/energy/power_fromsun.htm (accessed Oct. 19, 2009); “SOLutions Home Page,” SOLutions, http://www.cheqnet.net/~sunwise/#Services (accessed Oct. 19, 2009).