The Green Leaf

Solar PV + EV

January 15th, 2015
Wes Wada of Honolulu just installed a solar photovoltaic system on his home, which will help power the two electric vehiciles he and his wife drive around town. Courtesy Wes Wada.

Wes Wada of Honolulu just installed a solar photovoltaic system on his home, which will help power the two electric vehicles he and his wife drive around town. Courtesy Wes Wada.

Wes Wada of Honolulu is not your typical tree-hugger or environmentalist, but alternative energy has become part of his daily lifestyle.

Wada adopted alternative energy times three. He just hired Eco Solar to install a solar photovoltaic system (32 panels in all) on his rooftop in Honolulu last year to help power his home and his two electric vehicles. He's had the Nissan Leaf and Mitsubishi i-MiEV for three years, already.

So he's living the "Solar PV + EV" equation.


Solar PV + EV means living on sunshine as your main generator of electricity, but of course, there are many factors to consider before making this investment. (Read "Living the EV/PV Dream" by GreenTech Media).

For Wada, it's worked out well, as part of the Hawaii lifestyle.

"That's really the way to go, in my opinion," said Wada. "The key thing, No. 1, is you need to know what the daily commute is going to be."

On an island like Oahu, chances are your distance is going to be pretty short compared to what it might be on the U.S. mainland. The investment in the electric vehicles which he and his wife use have worked out, when rebates were factored in. If he were to do it all over again, Wada says he would lease the Nissan Leaf  instead of purchasing it. That way, he says, you don't have to worry about the battery two years later.

Consider us lucky, too, given that we have sunshine, lots of it, through most of the year.

For Wada, once named an "Energy Hero" by Hawaii Energycost savings and convenience were the main motivation for going green.

"Imagine never having to line up at Costco again for gas," he said. "In five to six years, the solar PV system will be paid off, then you get free electricity for the home and the cars. The convenience factor is really big."


The other perks – use of the HOV lane regardless of the number of passengers, free parking at meters and  the airport (there's a 30-day limit, according to the Hawaii Department of Transportation, but it's free of charge if you have an EV license plate), and dedicated parking stalls all add up.

The energy climate in Hawaii, today, is more uncertain, with NextEra's pending acquisition of HECO, plus the state utility's plan to raise fees for all electricity users, with extra fees for owners of solar PV.  Connecting the solar PV system to the grid is also a big uncertainty, with folks that have waited up to a year. If you've already got solar PV in place, the next natural step would be to consider an EV. At the same time, HECO is also offering a discounted time-of-use rate for owners of electric vehicles who charge up at non-peak hours.

Wada said he opted not to go with the time-of-use option, but he's definitely glad he opted for Solar PV + EV.

If you can't get approval for photovoltaic panels, Wada says there are still a lot of things you can do to cut back your electricity bill — LED light bulbs, a solar water heater, energy efficient appliances.


Most people worry about running out of electricity while on the road, but more charging stations are in the works, plus a start-up company is working on a mobile charging service for electric cars, according to Dave Rolf, executive director of the Hawaii Automobile Dealers Association. That sounds like a great idea.

"I would do it again, knowing what I know now," said Wada. "If people are really concerned about surviving in Hawaii and doing more with less, I think PV + EV is kind of a no-brainer."

What about you? Have you thought about investing in an electric vehicle in Hawaii? The number of EVs in the state reached 3,166 in December 2014. Are you more comfortable with a hybrid (with 19,256 in Hawaii, they make up about 1.7 percent of total passenger vehicles)?


The Toyota Mirai, Toyota's first fuel cell vehicle, is scheduled to be launched in Hawaii in November this year. A prototype will be available at the First Hawaiian Auto Show in March.

4 Responses to “Solar PV + EV”

  1. NotNasti:

    My question is why (Tesla Model S excluded) are electric vehicles so ugly? Put the technology in nicer looking vehicles, and more people would convert.

  2. Nina Wu:

    Agree. Would be nice to see better-looking EVs out there, Tesla aside...!

  3. UH91Alum:

    When I moved into Pearl City, the 1st thing I did was install a solar water heater. After 2 months, I was able to determine my "normal" energy usage (changed out ALL my bulbs to CFL and installed timers on the lights) and only needed 10 PV panels to "zero-out" my utility bill. PV only makes sense if you get just the right amount of panels, anything more. and the only PV installer & HECO benefits from the excess power you generate. Based on HECO's current policy, the excess kWH will only be credited for up to 1 yr - the anniversary of your system. After that, you lose all of it & start over. Hopefully, NextEra will not change this policy.

    I also drove a Camry Hybrid, savings were great until the battery started to fail after 7 yrs. The replacement cost of the battery basically negated ALL the fuel savings of having a hybrid. When the hybrid was limping on "gas engine" mode only, it's mpg rating was no better than a standard 4 cylinder car averaging 26-28 mpg. In addition to the "premium" cost of an EV or hybrid vehicle, today's lithium-based battery for EV & hybrid cars are still very costly to replace. My advice would be to purchase today's most fuel efficient gas-engine cars.

  4. Nina Wu:

    Good for you! You've taken steps to embrace solar and that's awesome. You make some good points here, too. It's not necessary to be excessive with the solar panels, just know how much you need to zero out. The credit is awesome when you see it on your bill, though...EV is not for everyone. Or maybe leasing an EV is the better way to go. I think purchasing the most fuel efficient gas car is good advice, too. Thanks for your comments.

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