The line was in a Business Week story about solar energy: "In Hawaii, Italy and other places with abundant sunshine and high electricity rates, it's already cheaper for consumers to install rooftop solar panels than to buy power from their local utility" ("Solar panels start to outshine mirrors," Bloomberg/Business Week, Oct. 13, 2011; www.bloomberg.com).
It is sort of true. There are caveats. That was apparent when none of Maui's solar companies contacted about the statement would offer data to support it. Some said their personnel might offer more information on inspecting my home for an installation.
That makes sense.
Hawaii environmental writer Jan TenBruggencate, an elected board member of the Kauai Island Utility Cooperative, said the statement can apply in a "very specific set of circumstances:
"You remain connected to the grid, the utility is willing to sign a net metering contract, both federal and state tax credits remain in place, and you have the financial wherewithal to front tens of thousands of dollars. . . . It may be cheaper long-term, but that depends somewhat on how you calculate the risk that the system will still be working optimally years down the road when you've fully amortized it. That assumes limited corrosion, the inverter electronics survive for years, no hurricanes, no kids throwing baseballs up on your roof, and all kinds of other things."
Other things include location, according to Stuart Zinner, information/computer science instructor at UH-Maui College. Zinner headed installation of a 15-kilowatt photovoltaic system on the campus that is generating between 40 and 80 kilowatt hours a day. The system has saved the college $18,000 in energy costs since installation last summer (maui.hawaii.edu/energy/).
Most homes would opt for systems of 2 to 4 kilowatts. Zinner offered general estimates on a 4-kw system with cost of installation assumed at $25,465. After federal and state tax credits, final cost to the homeowner was projected at $8,912. Assuming an average five hours of peak sunlight daily, the 4-kw system could generate 19 to 20 kwh a day. Based on Maui Electric formulas for energy fed into its grid, Zinner estimated savings of $220 a month in electrical costs and potential payback in four years. The assumptions include a south-facing rooftop having optimum solar exposure, minimal cloud cover and no shading from trees and structures. Homes on the slopes of Haleakala or Wailuku have significantly less sun exposure as do tree-shaded homes in Lahaina town.
There is potential for Maui homeowners in good solar locations, since the state Public Utilities Commission recently lifted a requirement for interconnection studies when PV grid connections reached 15 percent. That 15 percent requirement served as a cap on new PV systems in some districts. Interconnection studies would determine effects of additional intermittent power systems - wind and solar generators - on an electrical grids, since large amounts of fluctuating power input can affect reliability of a system, potentially causing spikes, brownouts and even blackouts.
A point of the Business Week story was that the price of photovoltaic panels is falling in large part because manufacturers in China are flooding the market - with lower labor costs, weak environmental restrictions and soft workplace safety standards. That could make new PV panels more competitive even as American PV manufacturers are driven out of business.
A Bloomberg analyses was cited as saying costs of PV systems are down to 17 cents a kilowatt hour, although the story offered no data on how that number was derived. If that's even close to true, it severely undercuts Maui Electric's 38 cents a kwh, of which 67 percent, 25 cents, is for oil.
* Edwin Tanji is a former city editor of The Maui News. He can be reached at hakumoolelo@earthlink.net. "Haku Mo'olelo," "writing stories," is about stories that are being written or have been written. It appears every Friday.
