On Top of the Aloha Beat BLOG


Photovoltaic install helps Kauai figure out net metering

I recently attended a one hour free workshop at the State Building in Lihue on the subject of a case study in Photovoltaic (PV). The presentation was deliver by Walt Barnes, an engineer who lives in the Wailua Homesteads, and who works for AT&T labs. Co-incidently, Walt's wife Anne is my fellow in the Rotary Club of Kapa`a AND the director of publicity and marketing for KIUC, the electric company cooperative that sells us our electricity, at greater than 40 cents a kilowatt hour.

Walt took to task to research, design, and engineer a photovoltaic system and has documented all his research and continues to track his results to assist island residents in understanding and demystifying the process and possibility of generating one's own electricity.

Walt told me he has delivered this presentation about a dozen times on island. There were about twenty folks in the room for the presentation i attended although the prior presentation at the state building was standing room only so this was repeat performance so more people could get educated.

Walt stated that municipalities, states and individuals are the entities currently enrolled in fighting climate change. It's NOT our government. Kauai is in the tropics and gets a lot of sun. First things first. If we don't already have solar water, that's the place to start at a bare minimum. Payback on solar water generation is 1.5-2 yrs. That's significantly quicker than with PV.

View of the PV installation: the 2 smaller panels in 2nd row from bottom are the original solar water panels

Rather than recite the deep science and math of what Walt Barnes has discovered and shared with our community, you can see all the data from Walt's experiments at www.walt-n-anne.com/pv/pv.htm.

The system that the Barnes' installed utilized net metering. That is, the electricity flows from where you have more of it to where you have less. The PV electricity made goes to someone else. The meter spins forward and backwards. It spins backwards when Walt is making electricity that he is not using. The idea was to size the system to make more electricity than Walt needed to make up for the fact that at nighttime he makes no electricity. Grid-tied PV is causing KIUC extra work. There is a practical engineering limit of how much one can have on the system. That limit is 5% of total demand. That would be 1.25% of total energy used on Kauai.

L-Brackets and rails go down on the roof first to secure the PV panels.

TGI (Garden Island Newspaper) recently reported that KIUC reached its net metering limits for residential and commercial customers. These limits were established by the Hawai`i Public Utilities commissioin after a next netering law was enacted in 2001. In 2005 there were only three people using net metering and this year 60 people are attempting to get their systems up and running. Consumers can continue to purchase and sell energy at the Schedule Q rate. Instead of selling back electricity to KIUC for retail, Schedule Q customers receive the wholesale rate, a lower price. Perhaps policies will change as more people become self sustaining with the PV efforts.

Walt's system generates 4.8KW
Costs were: 9K  in panels and inverters
4K rails and Misc.
-12K in tax credits  (two year installation) •
NEM Residential Payback
5KWH generated annually (creates a credit of $1950)

Walt's payback is 5.6 years +/- 20%. Remember, Walt designed the system AND installed it. So if you were paying a retail contractor to do that portion, the payback is closer to the 10 yr. range. The government provides a calculator to help size a system for your needs.Take their estimates with a grain of salt.


It's great to see someone sharing their experience with the entire Kauai community so we might all benefit from Walt and Anne's experience and learn from them.

Ron and Gwen Margolis
On Top of The Aloha Beat
Century 21 All Islands
email: ron@landinkauai.com
24 Hour Information Line: 800-582-9585
Cell: 808-346-7095

Ron Margolis, RA, CDPE, ABR Hawaii Life Real Estate Services 808.346.7095 email: ron@hawaiilife.com

Comment balloon 0 commentsRonnie Margolis • June 23 2008 02:24AM