Leaps of Faith in the Future: From Efficiency to PV to EV

After I did everything I could to make my home more energy efficient, I faced my first decision 12 years ago about whether to install solar panels as well. I remember friends asking me if they would pay back their extra cost in a reasonable period of time through electricity savings.  “Not yet,” I acknowledged, “you basically have to vote with your wallet on where you want your electricity to come from.  If I buy them and other people buy them, eventually they will be cost effective for everybody.”

Fast forward 7 years, and I made a decision to buy more solar panels.  This time, they were cost effective, mostly because the price of the panels and inverter had fallen just about as fast as electricity prices from the utility had risen.  They’re an even better deal today, and are an accepted way of cutting our energy bills in a sunny place like Durango.

In 2013, my wife and I faced that same kind of decision again with our car.  Our first instinct was to get a plug-in hybrid like the Chevy Volt or the Ford C-Max Energi.  They seemed like the perfect solution -- an electric car around town for all our short trips, and an efficient gasoline powered car for our longer road trips, all in one vehicle!

When we looked at the numbers, it was evident that they weren't strictly cost effective compared to just going out and buying a regular hybrid.  We could live with that, but the utter simplicity of an all-electric vehicle (EV) started to look even more compelling.  In the end, we decided to make a clean break from gasoline, and the complexity of a car with all the mechanical parts of a gasoline engine wedged into a small space under the hood next to all the electronic parts of an EV.

Even with the federal and Colorado tax credits adding up to $13,500, we knew an EV wasn’t the most cost effective choice.  There are much cheaper ways of driving around.  But buying an electric vehicle seemed to me the purest way to vote for the change we wanted to see in transportation, in the hopes that someday everyone will be able to buy an affordable electric car.

At the end of 2012, we ordered a Tesla Model S with the smaller of two available battery sizes (60 kWh) and none of the options to make it faster or more powerful.  It seemed powerful enough already to accelerate better than other cars we had owned and had a maximum range of 208 miles per charge.

Tesla delivered the car to us in May, and I immediately took it on a road trip to Crested Butte, Pueblo, Denver, Mt. Evans, Aspen, and back to Durango.  It worked great and was really fun to drive, but the charging infrastructure still wasn’t quite there to make the trip convenient.  I had to break up my trip into segments of 200 miles or less per day, with recharging overnight, or allocate a couple hours in the middle of each day to recharge at campgrounds and sparsely available charging stations to enable longer drives.

Since that time, Tesla has built out a Supercharger network along the west and east coasts and across the middle of the country that passes near Durango.  There are now Superchargers in Gallup, Farmington, Blanding, Moab, and Grand Junction that are all reachable on one charge from Durango. They make longer trips possible by providing free, fast (20-40 minutes) recharging roughly every 150 miles.  So I decided to try something much more ambitious:  a 3,000 mile winter road trip from Durango to northern and southern California, and then back home across the Arizona desert.  And my goal was to do the entire thing on free electricity, with minimal inconvenience.

So how did it work out?  The full details are on my blog at Ecova, but here’s the high level summary. The total trip distance was 3115 miles and total electricity use was about 1099 kWh, counting the losses in the charging process. This works out to an efficiency of 353 watt-hours/mile. That about $136 worth of electricity at today’s national average electricity rates, or 4.4 cents/mile.  

My actual out-of-pocket cost was only about 0.2 cents/mile or $7 total, because the electricity at Tesla’s Superchargers was free. I was able to charge at friends’ houses and hotels for free too, so I only paid for electricity at two campgrounds near Yosemite. I almost hit my goal of free fuel costs! I saved about $480 on the gasoline that a typical gas-powered car of similar size and features would have used.

Of course, I was still using fossil fuels from power plants.  It’s clear from the research done by the Union of Concerned Scientists and others that we still have a long way to go improving the generating stations that charge our electric vehicles.  In Colorado, the electricity comes primarily from coal, so a typical electric vehicle is no better than a 34 mpg gasoline car from a greenhouse gas emissions perspective, unless you have solar panels on your roof.

But other states are much further along.  In California, the electric grid is much more heavily powered by solar, wind, and hydro sources, making an electric vehicle there the equivalent of a 78 mpg gasoline car.  Arizona and New Mexico are in-between, with an average of about 49 mpg.  Given the regional mix of charging I did on my trip, a reasonable average might be 55 to 60 mpg-equivalent – not too bad!

Over the next 18 months, the Supercharger network will grow to span the entire country, largely eliminating the inconvenience considerations that have hampered electric vehicles so far.  I can’t wait!