Tag Archives: fuel cost

March 2020 Solar Production and EV Efficiency

My solar monitoring platform was available for an entire month and all of the panels on my solar system were fully functional.  This led to a pretty good March for solar production:

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Just under 578 kWh for the month.  This compares with ~316 kWh in 2019 and ~424 kWh in 2018 or an increase of ~83% and ~36% over each of those years respectively.  My guess is that the average year-over-year production increase will fall somewhere in the middle of those two on average over the course of the next year.  Only time will tell.

For the month, my household ended up “net positive” ~67 kWh.  My household was also “net positive” in March.  It is my assumption that the next couple of months will be big “net positive” months in terms of electricity consumption versus production since the period before the hot summer months is generally light on consumption.

One factor driving a lower level of electricity consumption is the fact that we are not driving much, if at all, as a household due to COVID-19.  All of my children’s activities have been cancelled and we are working from home.  I cannot remember if I have charged my Nissan Leaf in the two weeks we have been home from an aborted spring ski trip to Colorado.

For the month, I drove my Nissan Leaf ~652 miles at an average efficiency of 5.3 miles per kWh.  Almost all of those miles were in the two weeks before we locked down at home.  I “saved” ~746 pounds of carbon dioxide emissions compared to driving my truck assuming that I pulled all of the electricity from the grid at my utility’s average carbon intensity.  In the first quarter I have “saved” ~2,785 ponds of carbon dioxide emissions.  Given that I am now producing more electricity via my solar panels than my household is consuming, including EV charging, those carbon dioxide savings are even greater.  The same logic goes for the fuel cost savings.

April is going to be a weird month for sure.

Twenty Days in January with My Nissan Leaf

The biggest step that I have taken to decarbonize my transportation was to buy a used 2015 Nissan Leaf.  Depreciation and other market forces made purchasing a lightly used electric vehicle an easier decision than it had been in the past.  It also helps that I had already wired my garage for 240V operation, making charging that much faster than relying on legacy 120V outlets.

January 2019 was a weird month and I only owned the Leaf for twenty days of the month due to a lengthy process to get the car delivered.  No one wants to hear that their newly purchased car was on the delivery vehicle that went off the interstate in high winds.  Combined with a week or more of polar vortex and the first appearance of significant snow this winter I have a hard time making heads or tails of my driving results.

Anyway, for the twenty days that I had possession of the Nissan Lead I drove a total of 352.5 miles (~17.6 per day) at an energy efficiency of 3.6 miles per kWh.

Until the temperatures dropped into colder than a well digger’s rear end on the shady side I was average around 4.5 miles per kWh.  This goes to show you how much an impact using a resistive heater can have on your EV’s energy efficiency.  I have also come to discover that the Nissan Leaf’s battery has a thermal management system that will heat the battery in extreme cold to prevent “freeze up.”  That is just more energy used to make heat and not drive the wheels.

Regardless, I am still saving in terms of fuel cost and carbon emissions.  Based on my prior primary vehicle—a 2013 Ford F-150—I saved $12.73 in fuel costs and 372.1 pounds of carbon dioxide.  This assumes that I drew all of the power to move my Nissan Leaf from the grid, which when I rack and stack January’s solar production looks very likely.