May 2020 Solar Production and EV Efficiency

To paraphrase Dickens, it was the best of times—most electricity generated via my solar photovoltaic array every—and it was the oddest of times—all of my household’s driving total a little more than 150 miles.

First, my household’s solar photovoltaic array generated more than 900 kWh of clean, green electricity:

The interesting thing is that back half of this May was kind of gray.  There was a week span—easy to see on the daily production bar chart—where the sun did not poke through a low level of clouds.  Things picked back up at the end of the month to push the monthly production over 900 kWh.  My hope is that June can come in at more than 1,000 kWh.

In terms of production versus consumption, we ended up “net positive” just over 400 kWh.  This I a good number in and of itself, but it is even better considering that it represents my household’s entire energy usage.  Due to coronavirus we have had two people working from home full time, two kids attending school from home, my sister-in-law living with us while she is between jobs, and cooking all of our meals at home.  There has been very little energy “leakage” save for ordering pizza in one night because my sister was craving the most Iowa thing of all time—taco pizza from Casey’s.  Yes, pizza from a gas station is a big deal for some reason.  I do not get it, but I was not born here.

On the opposite spectrum is my driving in the Nissan Leaf.  For the month, almost our entire household’s driving came to just under 155 miles at an average efficiency of 6.0 miles per kWh.  Compared to my truck, I saved ~181 pounds of carbon dioxide from being emitted assuming that I pulled the electricity from the grid at an average carbon intensity for my service region.  This month I made sure to plug my Nissan Leaf—all told twice—during the height of the mid-day sun when my solar array was pumping out the watts.  Running on that funky yellow sun, baby!

The crazy thing right now is the sheer reduction in driving.  Just my driving, not including my wife’s driving, is down ~82% in April and ~83% in May.  As we are both working from home and not shuttling the children to activities our driving is down double or more whatever total mileage I have avoided driving.  That is a crazy reduction in such a short period of time.

Onward to June.  Stay safe out there.

April 2020 Solar PV Production…the Most Ever

My solar photovoltaic array’s production for April 2020 was the most my system has ever produced:

All right, this is less a function of any solar intensity and more a result of my adding an additional eight panels to my array at the end of 2019.  Nevertheless, over 840 kWh of clean, green electricity is a nice month.

The story gets better.  The delta between my system’s production and consumption was 396 kWh “in the black” meaning my home was better than net zero.  It was net positive electricity for the month of April.  I still have to do something about my home’s natural gas fired water heater and furnace.  Coronavirus has kind of put a dampener on any major purchases for the moment.

As expected, we did not drive very much at all this month.  I took the Nissan Leaf out for 115.0 miles at an average efficiency of 5.7 miles per kWh.  This represents 20.2 kWh of energy usage and a carbon emissions savings of ~133 lbs versus driving my truck assuming that all of my electricity was pulled from the grid.  Which, as I noted above, my household was quite positive this month when it came to electricity production.

Those 115 miles represent almost all of the driving for my entire household for the month of April save for a couple of trips in our ICE vehicles that we took to keep the fluids moving.  After this “adventure” we might consider paring down our personal vehicle fleet.

What is crazy about this whole not driving thing is the cumulative impact of not driving.  As of today my wife and I have worked from home for 31 work days.  Using an average miles per day of 22 we have avoided driving ~1,364 miles between the both of us just by not going to work.

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:

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.

January 2020 Solar Production and EV Efficiency

Okay, January kind of sucks if you are living the electrified life.  On average, January and/or February are the worst months for solar production and EV efficiency.  Why?

For my solar photovoltaic array the answer is in two parts: snow and clouds.  For part of the month, it is common for my panels to be covered with snow.  I have tried my best to knock the snow free with a foam roof rake, but this is really just scratching at the surface of the problem.

The second part of the problem is that the month of January is just not that sunny in eastern Iowa.  The sun came out on Saturday and everyone in the house sort of looked surprised.  It was a “Do you remember the last time you saw the sun” kind of moment.

The end result is that you do not make very much electricity.  For the month I am unsure of just how much my PV array produced because my monitoring setup is still not reporting correctly.  Needless to say, I know that I was in the hole ~400 kWh for the month.  Ugh.

The cold weather will also bit you on the rear end when you are driving an EV.  Granted, the cold weather will also impact the efficiency and performance of an ICE vehicle as well.

When you turn on the heat you watch your range and efficiency go into the tank.  On my 2015 Nissan Leaf which uses a resistive heater I can see the “guess o’ meter’s” range drop by at least 30% and more like 40% usually.

If it gets cold enough the “guess o’ meter” will also show less range because the batteries are chilly and cannot discharge as well.

To add insult to injury, regenerative braking is not as effective in the cold weather so more energy is lost to heat in the form of actually using the brake pedal.

However, given all of that downside I still managed to drive 850.5 miles at an average efficiency of 4.7 miles per kilowatt hour.  This compares with the same period last year where I averaged just 3.6 miles per kWh.  I chalk that up to the weather not being quite as harsh and me understanding how to wring more mileage out of my little Nissan Leaf.

For the month I saved ~953 pounds of CO2 from being emitted versus my prior vehicle assuming an average carbon intensity of electricity from the grid.

Like most people in eastern Iowa I am kind of excited to see February be here because it means an end to the ceaseless political ads and a potential break toward more electrified living amenable weather.

Final Report on 2019 “Resolutions”

It is time to take stock of my so-called New Year’s resolutions for 2019 and see how I did.

Without further ado, here is the list:

• Decarbonize transportation—My 2015 Nissan Leaf has been in the garage for about a year.  Over that time ~7,987 miles at an average efficiency of 5.2 miles per kWh. The Leaf saved ~9,119 pounds of CO2 being emitted compared to my prior vehicle.  Furthermore, I added ~62% generating capacity to my home’s solar photovoltaic array so for 2020 I should be driving on sunshine 100% of the time.
• No more Amazon—A little bit of failure and a little bit of success. I definitely spent a lot less money at Amazon than in prior years, but it speaks to the company’s ubiquity that I ended up buying anything at all.  Want to buy that odd little gadget?  Guess what, Amazon is about the only place to find fulfillment.
• No more Walmart—A little more success as I the only trips to Walmart were few and far between for the year. Over the course of the entire holiday shopping season it never entered into my mind to even shop there.  Once a store is no longer part of your “consideration set” that has to be considered a success.
• Read twenty five books—51 books read.
• Drink local—Pretty good, but I think I can do better in 2020.
• Declutter my house—Fail. My family and I spent some time getting rid of old clothes and other stuff that was taking up space in our closets.  However, it feels like we replaced whatever we got rid of over the course of the year.  I know that I will never be a fervent follower of Marie Kondo’s methods nor will I ever embrace modern minimalism.  I thought I could do a little better.
• Replace existing toilets with low volume flush models—One toilet was replaced. A second toilet is scheduled to be replaced in January.  The third toilet in the house does not get enough use to merit replacement at this time.
• Plant at least five trees—Two Norway spruce trees are in the ground.  Three Colorado blue spruce trees in the ground. Mission accomplished.
• Reduce lawn coverage—Fail. I had the best of intentions to start replacing some of my lawn with mixed plantings and landscaped beds.  While I got the trees in the ground the rest of the plan did not come together.  This is where I am going to focus my 2020 landscaping efforts.
• Ride 2,500 miles on gravel roads—Over 3,000 miles ridden on the year. Mission accomplished.

 

For 2020 I am going to try and build on what was done in 2019.  The goal is to improve each year.  Different goals or different metrics, but the overall theme is improvement.

Stay tuned!

November 2019 Solar PV and Nissan Leaf EV Performance

November was an ugly month for solar photovoltaic production:

Why?  My system was disconnected and shut down due to a planned upgrade.  The guys from Moxie Solar installed an additional 8 panels and the attendant “balance of system” components like a new grid tie inverter.  The 8 additional panels represent an approximate 62% increase in nameplate capacity for my system.  Given the orientation and installation location are virtually the same as the previous 16 panels I expect to see an approximate 62% increase in solar production once the array is powered up.

This has to be one of the most frustrating parts of a solar installation.  The rooftop install and other system components were done in a little more than a working day.  The city inspection was done in about fifteen minutes and done a few days after installation.  The permission to operate and the simple act of flipping the switch?  I am still waiting.

See most of those zero production days in the last week of November?  That is the cost of waiting for someone to come over from the electric utility and watch a person from the solar installer flip a switch.   It is like a bad anecdote about union rules from the 1980s.  Soon…the switch will be flipped soon.

This might also be the last month for a while where I seen an average of over 5 miles per kilowatt hour in my Nissan Leaf.  For the month I drove a total of 619 miles that used 123.8 kWh of electricity at an average efficiency of 5.0 miles per kWh.  At an average carbon intensity, I avoided emitting ~702 pounds of CO2.

What November really taught me is that cold weather kind of sucks for an EV.  My particular Nissan Leaf is not equipped with the heat pump, so it relies on a resistive heater to provide any level of defrost in cold weather.  Most of the time my trips are short enough that I just deal with a cold cabin while the heated seat and steering wheel keep me cozy.  Put three passengers in the car and the windows start to fog up pretty quick with hot breath.  There is nothing so dispiriting as watching the guess-o-meter drop by 30% or more when you turn on the heat.

It is not enough to dissuade me from recommending an EV in general or an older Nissan Leaf in particular.  There is something to be said for taking advantage of a market dynamic like extreme depreciation.  You can have your Tesla Model 3.  I will take my solar panels, Nissan Leaf, and decarbonized home to the bank every day.

The Financial Math Behind Decarbonization

What if I told you that for the price of a base model Tesla Model 3—good luck actually finding one—you could decarbonize your household?

What if I told you that this is not a thought exercise but an examination of steps already taken?

Are you ready?

The price for base Tesla Model 3 is ~$35,000.  That is the price assuming that you can actually purchase the so-called “standard range” model and before any applicable tax credits.  For the purposes of this discussion I am going to leave tax credits aside for the time being.  So, we are working with a starting price of $35,000.

For that price you get an electric vehicle that has to draw power from the grid, which depending upon your locale and power company may support coal fired electricity.  It may also support fracking for natural gas or the nuclear power energy, assuming any of that industry remains in your region.

What else could you do with that $35,000?

Over the course of the past two and half years I have installed solar photovoltaic panels on my roof in two phases.  Why two phases?  Initially, my power company would only allow my roof mounted solar photovoltaic array to exceed my annual consumption—based on average expected production—by ~10% or so.  Considering how little electricity my household used in comparison to the average this worked out to a system of 4.64 kWh.  This initial phase cost me ~$11,000 before tax credits at the state and federal level.

In the past month I added ~62% more capacity to my existing solar photovoltaic array at a cost of ~$7,500.  In the past year I added an electric vehicle to the mix, which has upped my household consumption, in addition to a few winter months in 2019 where my prior panels were covered under deep snow curtailing production.  We also forgot to turn off a garage heater, which ran up the electric bill in February.  All told these changes goosed our consumption just enough to allow me to install an additional eight panels on my roof.

As it stands right now the photovoltaic array on my roof has a nameplate capacity of 7.52 kWh.  This was complete at a total cost of ~$18,500 before any tax credits.  Remember, we are leaving tax credits aside for the moment.  Assuming my household usage patterns hold—including one electric vehicle—this system will produce more than 100% of my household’s electricity requirements for the year.  The estimated excess production should allow me to replace my natural gas water heater with an electric air source heat pump model further reducing my household requirements for fossil fuels.  With the water heater replaced in the next year my household will only use natural gas for the forced air furnace in the colder months.  Trust me, I am looking at options to replace that as well.

What about the electric vehicle?  This is where the power of the market and a realistic assessment of one’s needs come into play.

A Tesla Model 3 is a fine automobile.  Dollar for dollar, it may be the best vehicle on the market right now when one considers its relative performance and environmental bona fides.  However, it still costs $35,000.

In January of this year I purchased a used Nissan Leaf for ~$11,500.  The Leaf had ~33K miles on the odometer, but the battery was in great condition being that the 2015 and later model years utilized an updated architecture that corrected some of the prior model years’ most glaring problems.  A purchase price of more than eleven thousand dollars might sound like a lot, but this was a car that retailed for more than $30,000 when new.  Losing two thirds of car’s value without high mileage is crazy town.  Or, good for the person who can take advantage.

If one can live with a lesser range, one can take advantage of the market punishing these older EVs for not being up to Tesla’s newer standards.  If one drives in town, for the most part, there is no disadvantage.  In almost a year of daily driving I have had just one instance of the range “guess-o-meter” dropping below ten miles remaining and I have never experienced the indignity of “turtle mode.”

How does this all add up?  Total cost for me to purchase an EV to replace all of my daily driver miles and enough solar photovoltaic capacity to power me entire household, including EV electricity requirements, was less than $30,000 before any tax incentives.  Compared to a $35K Tesla Model 3 I would say that I ended up in a better place.  Five thousand or so dollars better, mind you.

This is not to diminish the decision of someone purchasing a Tesla or any other EV.  Rather, it is to illustrate that there is an alternative path to decarbonization that is neither as expensive as portrayed by many and without any appreciable downsides.

The future is now.