How does Hawaii compare with the rest of the country?

How do we compare EV-wise? Surprisingly, we are in second place.

The number of EV’s in a region (e.g. a state) is often reported as the number of EV’s per 1,000 people. That way the more populated states won’t be disproportionately reported.

The following map [1] shows the number of plug in electric vehicles (PEV’s) (which includes all electric and plug in hybrids) per 1,000 people in 2015.

The top 5 states were (measured in EVs per 1,000 people)

  • California 4.7
  • Hawaii 2.9
  • Washington 2.3
  • Georgia 2.2
  • Oregon 2.0

Not surprisingly, California led the U.S. They often set the trends.

Surprisingly, Hawaii was in 2nd place. That is amazing because the electricity to recharge the EV batteries costs 2 – 3X as much in Hawaii as on the mainland.

How did this happen? We have our size and location in our favor. Because Hawaii consists of relatively small islands, most commutes are well within the range of current EV’s. On the mainland, commutes are often longer so “range anxiety” discourages EV ownership. Another factor is the correlation between EV ownership and PV ownership; 39% of EV owners in California have PV. [2] Hawaii ranks 2nd in the nation after Nevada in solar capacity per capita. [3] People who get PV systems do it for financial and environmental reasons and many of them also see the benefits of EV’s.


Who are the top-selling manufacturers of EVs?

Almost all car companies now offer electric vehicles, but who are the top selling manufacturers of plug-in EVs (PEVs) in the US?

Breakdown of units sold by model in 2016:

  • Tesla Model S 29,156 (BEV)
  • General Motors Volt 24,739 (PHEV)
  • Tesla Model X 18,028 (BEV)
  • Ford Fusion Energi 15,938 (PHEV)
  • Nissan Leaf 14,006 (BEV)

*BEV = battery electric vehicle, PHEV = plug in hybrid electric vehicle

The top five best-selling models in the U.S. accounted for about 65% of total plug-in cars in 2016.


How much maintenance does an EV require?

Much less than a gasoline vehicle. Here is a table showing the differences.

  Gas Vehicle
recommended interval
n/r = not required
Check oil level Every fuel fill up n/r (no oil)
Check coolant level Every fuel fill up 125,000 mile life expectancy
Check automatic transmission fluid level Monthly n/r (no ATF)
Replace oil and filter Every 6,000 miles n/r (no oil)
Replace engine air filter Every 15,000 miles n/r (no filter)
Replace spark plugs Every 40,000 miles n/r (no plugs)
Replace engine coolant Every 60,000 miles 125,000 mile life expectancy
Replace muffler As required n/r (no muffler)
Replace brake pads As required Less often because of regenerative braking
Emission test Annual inspection in some states n/r (zero emissions)
Waiting in line to refuel or while refueling Every tankful n/r (if charging at home)
With wireless charging, you don’t even need to plug in your car.
Washing vehicle As required As required

How much can I save in annual fuel costs with an EV?

Put your money towards electricity, rather than gasoline.

Visit the Savings page to get to the “savings estimator” to see how much you can save compared to your gasoline vehicle.

If you can charge your EV battery using your PV system, you can get the equivalent of over 80 MPG!

Why does the new car sticker say 114 MPGe when the car doesn’t use gas?

It is confusing, but here is an explanation.

If you buy a new EV, the sticker on the window will show an MPGe figure as required by law. On the Nissan Leaf it might be around 114 MPGe. That figure is based on the theoretical electrical energy that can be obtained from a gallon of gasoline. It does not factor in the cost of gasoline or electricity.

There is a calculation that you can do that factors in the cost of gasoline and electricity so you can get a more tangible idea of the efficiency of an EV.

How much do you pay for gas? Maybe $2.70 per gallon?

Instead of spending that $2.70 on gasoline, spend $2.70 on electricity to charge your EV battery and see how many miles that will get you.

That will be the “equivalent MPG” for your EV.

Click on the “Savings” link on the home page to get to the “savings estimator” to see the equivalent MPG for your EV.

If you can charge your EV battery using your PV system, you can get the equivalent of over 80 MPG!

How much will my monthly electric bill change if I get an EV?

Your electric bill will go up but your gasoline bill will go down.

Visit the Savings page to get to the “savings estimator” to see your estimated ANNUAL fuel (i.e. electricity) costs with an EV.

If you just want a rough idea how much your MONTHLY electric bill will change, see the table below. Figures are from the “savings estimator” based on electricity prices as of January 2017. It assumes that you

1. do the commute 5 times/week
2. have a Nissan Leaf (most popular EV on Kauai)
3. do not have a PV system (you are paying residential rates)

  Daily round trip commute (mi) Monthly electricity cost ($)
10 20
20 39
30 59
40 79
50 98
60 118

How much does an EV cost?

This article is intended to give you some idea of what you can expect to pay for your EV. Please do your own research before getting your EV.

The Nissan Leaf is used as an example since it is one of the more popular EV’s on Kauai.

A new 2017 Nissan Leaf has a base price of $30,680. With a $7,500 tax credit that comes to $23,180 before taxes and fees.

As of April 2017, a three year old 2014 Nissan Leaf will cost around $9,900 before taxes and fees from a car dealer. And if you want to get it in a private party you can expect to pay ~ $8,100 before taxes and fees.

Kelley Blue Book is a convenient source of pricing information. See below for an example page.

Sample Kelley Blue Book Listing

If you decide to have a level 2 (220 Volt) charger installed at your home, that will cost between $300 and $600 plus installation.

Should I buy new or used?

The pros and cons of buying new or used

When looking for a car, one of the first questions which comes up is, should I get a new, leased, or used car. Dealers of course want you to lease or buy new since it is the most profitable for them. Used cars are the most affordable but unforeseen out of warranty repair costs are the main concern. The next question is should you pay cash or finance the car. The answers to both questions depend on your personal preference, risk tolerance, and financial situation.

This article gives some recommendations from the writer. Please do your own research before getting your EV. The Nissan Leaf is used as an example since it is one of the more popular EV’s on Kauai.

Buy used. Generally, and in the long run, it is less expensive than buying new or leasing. You’ve probably heard the expression that a new car will depreciate 10% as soon as you drive it off the lot. The first year’s depreciation might be 19%. If you calculate out what that comes out to, you might think twice about buying a new car.

Buy a 3 year old car. Car leases generally run 3 years so there may be more inventory to choose from than for 2 year or 1 year old cars. Also at this point, the depreciation rate will have decreased considerably. The Leaf has a 3 yr/36,000 mile (which ever comes first) basic warranty. (See below for longer warranty on powertrain and battery.) If you buy a 3 year old Leaf, most likely it will be out of warranty. But keep in mind, EV’s are simpler than gas cars. There are no pistons, spark plugs, mufflers, gas pumps, oil pumps, etc. so there is less to go wrong. Tesla’s business model is to make money on selling new cars, unlike the traditional car company’s model of making money on service. That also tells you something about EV reliability.

Buy from a car dealer. It will be more expensive than buying from a private party, but the dealer will check the car over before putting it up for sale. Even though they sell the car “As Is,” they will often take care of minor issues within the first few days. Check on Hawaii’s Lemon Law. They may take care of any outstanding recalls.

Be sure to see the FAQ, “What’s all the fuss about the battery?”

Finally, make sure the charging cable and owner’s manual comes with the car.

The warranty on the 2013 Leaf is summarized below:

Nissan Leaf warranty

Where can I get a used EV?

Some tips for finding other great affordable options

One place to find a used EV is on Craigslist.This article focuses on Nissan Leafs since they are one of the more popular EV’s on Kauai.

There are not a lot of used Leafs on Kauai so you might have to widen your search to all of Hawaii. Also you can put other filters on such as maximum model year and maximum mileage. In the example Craigslist page below, the max model year is 2014 and the max mileage is 30,000. This search produced 45 Leafs for sale in the middle of April 2017.

Sample Craigslist search

The listing includes dealer and private party cars. Some of the dealers on the other islands are willing to ship a car to Kauai but without seeing the car, you might have some issues with it when it arrives.

Other than taking a trip to the other islands, if you have a trusted friend on the other islands you can have them take a look at the car and report back.

There are used car dealers on Kauai who go to Oahu regularly to purchase used cars at the weekly auto auction. You can let them know what you are looking for and they will let you know what they can do for you.

Once you find a candidate, you can use the Kelley Blue Book to figure out a reasonable price to pay.

What is the correlation between EV ownership and PV ownership?

It may be higher than you think.

Not surprisingly, the correlation between Electric Vehicle and Photovoltaic ownership is fairly high. In California, 39% of EV owners have PV.

PV ownership makes financial and environmental sense. People who have considered getting an EV are likely to have considered getting a PV system for the same reasons.

The corollary is that 61% of EV owners don’t have PV. That makes sense. These may be the people who rent, have a property without the space, orientation, or sunlight for PV, or don’t have the budget for a PV system.

Finally, besides the financial and environmental benefits of having both an EV and PV system, there is the less quantifiable feeling of independence one gets with these systems. Being less reliant on the electric utility and oil companies can be satisfying.

Can I charge my EV with my PV?

Using your photovoltaic system to charge your electric vehicle

This is the simplified version of Charging your EV with your PV. It doesn’t require you to analyze the hourly bar chart provided by Kiuc/SmartHub. You can get an estimate of the daily energy available to charge your EV and power available to operate a charger by merely looking at your monthly electric bill. Please contact for assistance with these calculations.

See sample bill below. Halfway down the bill is the “KWH” line. The number in the “USAGE” column is the energy purchased from KIUC. Below the “KWH” line is the “AUX” line. The number in the “USAGE” column is the energy generated by your PV system and sold to KIUC.
Sample KIUC Electric Bill

If you divide the energy sold to KIUC by the number of days in the billing period, you get the average energy sold per day.

Typically ~ 80% of the energy generated during a day is generated between 9:30 AM and 2:30 PM. That is the best time to charge. If you take 80% of the average energy sold per day, you will get the amount of energy available to charge your EV battery.

Finally if you divide the energy available to charge your EV battery by 5 hours, you will get the power available to operate your charger.

Example using the electric bill above:

  • energy generated by the PV system and sold to KIUC: 477 kWh
  • days in the billing period: 33
  • average energy sold per day: 477/33 = 14.5 kWh/day
  • best time to charge: 9:30 AM – 2:30 PM
  • energy available to charge the EV battery: 80% x 14.5 = 11.6 kWh
  • power available to operate the charger: 11.6/5 = 2.3 kW

How much range does 11.6 kWh get you? The 2013 Nissan Leaf gets 85 miles/24 kWh so 11.6 kWh will give 41 miles of range.

The Nissan Leaf 120 V Level 1 trickle charger draws 1.4 kW. It can be powered by the PV system.

In order to determine whether your PV system has the capability to charge your EV, you will need to get details about the energy you sell to KIUC. This information can be charted by the SmartHub app* on the KIUC website. Below is an example of a bar chart for our PV system.

kiuc energy usage example

Time of the green bars/ hours available

The red bars show the energy we purchased from KIUC and the green bars shows the energy we sold to KIUC over the course of an average day during the November 2016 billing period. Each tick mark on the horizontal axis represents a one hour period.

The red bars are at a low point in the early morning hours because our energy usage is lowest at that point. The only devices operating are the refrigerator, cable box, router, modem, and computer and phone chargers. We typically wake up in the 6 – 7 AM period. Kitchen appliances are turned on and the red bars start to increase in size.

Typically in the 8 – 9 AM period, the PV panels start producing energy so the green bars start showing up. They increase in size and might peak in the 12 – 1 PM period when the sun is directly overhead. The bars then decrease in size. The last one is in the 4 – 5 PM period. The green bars determine the hours when you can charge your EV using PV.

Sum of the green bars/ energy available

The units on the vertical axis of the bar chart is kilowatt-hours (kWh) of energy. For example, the green bar at 12 noon shows that 1.8 kWh of energy was sold to KIUC in that hour. If you add up all the green bars, you will get the total energy sold to KIUC on an average day. In the example it is 9.7 kWh. That is the PV energy you have available to charge your EV battery and that will in turn determine how many miles you can drive using PV generated energy.

Height of the green bars/ power available

The last piece of information that you need to know is the power your PV system has available to charge your EV battery. Energy and power are related by time. Lets say you have a 65 watt (incandescent) light bulb. It draws 65 watts of power when you turn it on. If you turn it on for an hour, you will use 65 watts x 1 hour = 65 watthours (or 0.065 kilowatt hours) of energy.

On the bar chart, the four green bars starting at 10 AM all show at least 1.5 kWh of energy available. To convert that to power available, you divide by 1 hour since each bar represents energy available over a one hour time period. 1.5 kWh/1 hour = 1.5 kW. That is the PV power you have available to run your EV charger.

Putting it all together

  • Hours: the best EV charging time is the four hour period from 10 AM to 2 PM.
  • Energy: During these hours, 6.6 kWh of energy are available (adding up the four green bars). The 2013 Nissan Leaf has an 84 mile range from a 24 kWh battery. 6.6 kWh of energy translates to 23 miles of range.
  • Power: The trickle charger which comes with the Nissan Leaf, is labeled 120 VAC and 12 Amps which translates to 1440 Watts or 1.44 kW which is less than the PV power available.

Of course not everyone is able to charge midday and not everyone has a commuting range within the range of the PV generated energy. But there are probably hundreds of residents here (out of the 3,500+ households that have PV) who can take advantage of their PV system for EV charging. This example is intended to illustrate the analysis required to do so.

The reason there are red bars in the midday hours of the second chart is because of clouds. On cloudy days (and when a cloud passes over), the PV energy production will drop enough so that energy has to be purchased from KIUC to meet household demand.

If you multiply the energy generated on an average day by the number of days in the billing period, you will get the total energy sold to KIUC for that billing period. That is a good check to see how this chart ties in with your electric bill.

Not all the PV energy is convertible into battery energy. There will be some inefficiencies in the AC to DC conversion process.

Keep in mind that the bar chart shows the average PV energy available. On rainy days, the energy production will be less than average. If you are charging up on a rainy day during normally sunny hours, you will likely be buying energy from KIUC.

I confirmed the power draw of the 120 volt charger by using a Kill-a-Watt meter (gadget you plug into a wall outlet and into which you plug in the device you are checking). It showed 1.3 kW.

If you aren’t able to consistently charge between 9:30 AM and 2:30 PM (example: you are only around for 3 of those hours) you might save money by using a Level 2 charger. The Level 2 charger may exceed the power from your PV system but it charges 3 – 5 times faster than the Level 1 charger. (In this example, you might use your Level 2 charger for 3 hours rather than your Level 1 charger for 9 hours.)

The 220 V Level 2 charger draws between 3.5 kW and 7.2 kW depending on the charger model and charges 3 – 5 times faster respectively than the Level 1 chargers.

Our electric meter was defective so it was replaced. That was just before we purchased our EV. The chart shows data after we purchased our EV. Had we not been charging our EV, the green bars in the 10 AM to 2 PM period would be about 1.4 kWh higher.

How to get the bar chart in the SmartHub app

  • Go to KIUC’s SmartHub Page
  • Create an account (if you don’t already have one) and then log in
  • Click on “My Usage” in the tool bar
  • Scroll down to “Average Usage” in the pop up menu
  • Under “Report,” scroll down to “Time of Day” in the pop up menu
  • Under “Date Range,” select a suitable period (e.g. one billing cycle)
  • Click “OK” and the bar chart will show up

What are some misconceptions about EV’s?

Don’t believe everything you’ve heard.

1. Driving an EV is like driving a golf cart.

The Tesla Model S can go from zero to 60 faster than any other street-legal car around. That includes Ferraris, Lamborghinis, Bugattis and any other crazy exotic sports car you can think of. The Tesla Model S P100D, with 760 horsepower and all-wheel-drive, jumped from a dead stop to 60 miles an hour in 2.28 seconds in a test by Motor Trend. [1]

2. There aren’t enough charging stations in Kauai.

That depends on where and how often you need to charge up. In the U.S., 81% of EV charging occurs at home, 10% occurs at public charging stations and 7% at work. [2]

Charging is usually done at home because it is cheaper and more convenient. Right now some public charging stations let you charge for free but that may not last. Also, the amount of charge you can get while running a short errand may not be worth the time to plug in.

On the mainland, when driving long distances (more than the range of the EV) requires refueling. On Kauai, unless you are driving from one end to the other, this usually isn’t an issue.

Salespeople, delivery people and others who drive to multiple locations and then back to home base (where the total distance is close to the range of the EV) may get “range anxiety.” These EV owners will have to plan out their charging stops. An alternative is to buy a newer model car with a higher range.

3. You’re going to have to replace the battery in a few years.

See FAQ about batteries.

4. You’re going to have to install a 240 V outlet.

EV’s come with a charging cable known as an EVSE (Electric Vehicle Service Equipment). They generally run on 120 Volts (ordinary household receptacle). This will work fine but it is relatively slow (adds ~ 5 miles of range/hour). If you want to charge faster you will need to have a 240 Volt receptacle installed and buy a 240 Volt EVSE (adds ~ 15 miles of range/hour).

5. EV’s have degenerative, co-generative, or regenerative braking.

The term Nissan uses is regenerative braking drive mode. The Regenerative Braking System captures energy while you coast or brake, and recycles it back to the power supply. Regenerative Braking does not use the brake pads (which would dissipate the energy as heat) so it does not require more frequent brake pad replacement, in fact the opposite (see FAQ about EV maintenance). [3]

6. See more Q & A’s. [4]

What’s all the fuss about the battery?

Just that – a fuss about nothing.

One of the most frequent rumors this writer has heard about the lithium ion batteries in hybrids and EV’s is that they need replacing after 5 years and they are super expensive.

It is just a rumor started by the skeptics who would prefer to stick to their gasoline vehicles. If you ask a hybrid or EV owner about the battery in their car, they will most likely give you a completely different answer.

If you are buying a used Nissan Leaf, check the battery capacity level on the dashboard display. It tells you how much life is left in the battery. When we bought our 2013 Leaf in 2016, the battery capacity was at 11/12. It is still there 4 months into 2017 and with 40,000 miles on the odometer. This gauge is right next to the battery available charge gauge which estimates the range in miles you can drive.

If the battery capacity level drops enough, the automotive students at Kauai Community College, can recondition the battery. Currently (2017) they can recondition the nickel hydride batteries of the Toyota Prius. At this point, the Nissan Leaf’s batteries are still “new” and under warranty. In the future, KCC will be able to recondition the lithium ion batteries in the Nissan Leaf. The cost to recondition a battery is approximately $1K vs. a new battery from the dealer will cost around $5k.

There is also another way to check the battery condition. You need an app called Leafspy and an On Board Diagnostic II (OBDII) scanner plugged into your car. One of the screens will show the State of Health (SOH) of the battery. It is a measure of the power fade and capacity fade of the battery. That is explained on the video in the link below:

4 months into 2017, our 2013 Leaf shows a SOH of 81% on the Leafspy app. How this correlates to the 11/12 (or 92%) battery capacity level on the dashboard display needs to be explained.

If battery range is going to be an issue, the newer Leafs have longer ranges. The 2014 and 2015 year models both have an 84 mile range. The 2016 S model has a 84 mile range while the SV and SL have a 107 mile range. All the 2017 year models have a 107 mile range.