Sunday, January 04, 2015

Your Garage as a Gas Station

I had evaluated electric vehicles previously to determine if they actually were more efficient than cars with internal combustion engines, and found that (at the time) they did have a lower carbon footprint and would save me considerable amounts on fuel costs. Of course, that was before gas prices dropped nearly 33% in a single week - however I knew the prices were being artificially deflated and would eventually push back up. An added bonus remained that I would no longer be late to work because I had to navigate out of my way and fill the tank.

I was able to take a Leaf out for an extended test drive and make sure it fit my commute - which it did. I couldn't find another auto manufacturer that actually had an EV on the lot aside from Tesla, so the Leaf was the only auto at my price point. Luckily there are many Nissan dealerships in my general area and I ended up picking a Model S Leaf that I have been driving for a few weeks now.

One great thing about an all-electric auto is that your garage is transformed into a "gas station," and you never need to leave your house to refuel. Bear in mind this does not necessarily mean you can use your normal 120V outlets to charge the car (using a Level 1 plugin-in charger) - you will at the very least need a dedicated circuit for charging, lest you blow a fuse from too much load. On my 24-hour test drive I quickly found out that the 120V outlet in the garage was on the same circuit as the master bathroom; when the car's 120V charger was powering up the battery it was consuming 11.3A of power, and a typical hairdryer will eat 12.5A. The combined 24A of load will trip your typical 15A circuit breaker quickly.

Ultimately a 6 kW, 240V/30A (Level 2) charger is necessary for home charging since even a dedicated 120V outlet will require 21-ish hours to go from empty to 100% charge. Normal usage often requires a 10.5 hour charge with 120V, which can easily be done in 4 hours with a Level-2 charger. The good news is that while the chargers offered through the dealership appear to be fairly expensive, Home Depot and Amazon will sell Level-2 30A chargers for under $500. If you add in the cost of an electrician adding a 40A 240V dedicated circuit, you can have a 6 kW charging station for under a thousand bucks. The daily cost per kilowatt will be the same, and while there are some who worry about peak/off-peak charging hours most residential agreements seem to bill based on volume, not based on time of day. 6 kWh at 2 AM is billed the same as 6 kWh at 2 PM.

The technology is changing rapidly. Level 2 chargers are rapidly eating from 20 amps to 30 amps to 40 amps, and Tesla is building a nationwide Level 3 charging network based on renewable energy. It's hard to say how all of this will play out... in 5 years we may have sedans with a 400 mile range... in 10 years we may have self-driving cars in metro areas... in 20 years 25% of new car sales may be EVs. Ari Jay's comparison between the Leaf and the Tesla S85 is a great example of the current state of the market - in the end both cars are great, to serve two different purposes and two different drivers. We're getting past early adoption, sliding past the peak of inflated expectations and heading towards the trough of disillusionment. Sure people are getting a bit anxious on range and worried about cost... but on the other side is mainstream adoption, and the widespread infrastructure to support electric vehicles and cross-country road trips.

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