Tag Archives: PV

Deeper Decarbonization by Intent and Accident

One of my 2020 “goals” was a deeper level of decarbonization.  In prior years I have installed solar panels (twice) and purchased an electric vehicle.  However, for 2020 I wanted to examine other parts of my lifestyle and see where I could decarbonize even more.

The first area was lawn care and its attendant equipment.  As anyone who cares about the air we breathe knows, lawn equipment powered by small gasoline engines is one of the dirtiest sources of air pollution that we use on a regular basis.  God help you if you are still rolling around with a two-stroke mower or string trimmer.

For the lawn care “season” so far I have mowed my lawn 11 times with my new battery electric mower and string trimmer.

Each mowing session represents approximately 1 hour of small engine runtime eliminated.  Depending upon the study and assumptions, an hour of small engine runtime is equivalent—in terms of emissions—to approximately 100 miles of automobile travel.  Considering I a running 100% “on the sun” right now you could say that my change in mowing equipment has resulted in the equivalent of reducing driving by 1,100 miles.

While reducing CO2 emissions is a big deal, it is even more important to reduce other types of emissions like small particulate and gasses other than CO2.  This is where reducing small engine runtime is so beneficial.  Without catalytic converters or other advanced emissions equipment, small engines are essentially belching out pollutants like it was 1972.   There are no hard estimates, but there are guesses that for every hour of mowing something like34 pounds of “other” pollutants are shot into the air. This includes things like nitrous oxide, carbon monoxide, and particulate matter.  The image of an American lawn as some kind of green idyll takes on a whole other bent when you consider the maintenance costs.

The second area where I was going to decarbonize was commuting.  Well, commuting is out because of coronavirus.  By accident both my wife and I have ended up cutting our commuting dramatically since mid-March.  Through June 30th we have avoided commuting for 63 days—not counting furlough, vacation, or holidays—which works out to a combine savings of ~2,500 miles driven and ~3,300 pounds of carbon dioxide emissions.

My original goal had been to replace 500 miles of driving—EV or otherwise—with the equivalent of human powered transport.  However, as you can see my household is blowing those goals out of the water in a totally different way.

There are some other areas of my household that I am looking to decarbonize in the coming months, but restrictions and closures due to coronavirus may impeded the progress toward those goals.  Regardless, I think that between the revised lawn care routine and cessation of commuting there has been some good progress made toward any goal of emitting less carbon dioxide and other emissions.

Over a Megawatt Hour of Solar and a Little Bit of EV Driving in June

June’s solar production ended at ~1.14 MWh.  Yep, my expanded solar photovoltaic array produce more than a megawatt hour of electricity for the month.  That feels like progress:

June 2020 Solar

Overall, my household ended the month producing ~544 kWh more than we consumed.  For the year, we are “in the black” ~995 kWh.  Quickly, I am approaching the point where I am net positive since installing my first solar panels a few years ago.  With July—traditionally the best month for solar production—I could reach that milestone before the summer is out.

Yes, I draw power from the grid.  However, it is my contention that if everyone were attempting to be net positive in terms of their power consumption this world would be a better place.  If enough people were doing just that we would have a huge portfolio of generating assets across the United States that would go a long way to curbing greenhouse gas emissions.  All right, I will get off my soap box.

The total number of miles driven for the month went up compared to prior coronavirus impacted months mainly as a function of actually leaving the house to shop for groceries and taking children to their limited activities for the summer.  Still, I only drove 254.3 miles for the month of June at an average efficiency of 6.2 miles per kWh.

Compared with my truck—which is an untrustworthy mechanical beast that left me stranded on the side of the interstate—I saved ~298 pounds of carbon dioxide being emitted, assuming that I pulled all of the electricity that I required from the grid at an average carbon intensity for my area.  Obviously, I am pumping out quite a bit more solar than required by my household so the actual emissions savings are probably even greater.

The crazy thing over the past three months has been just how much our household driving has been reduced.  For April, May, and June my driving is down 82%, 83%, and 54% respectively.  This takes into account that we have been using the Nissan Leaf for almost 100% of our local and regional trips.  So much so that my wife sold her car to her brother.  Talk about savings.  Plus, there is so much more space in the garage now.

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:

May 2020 Solar

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:

April 2020 solar

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.

Decarbonizing Transportation Due to Coronavirus

Like almost everyone else in the United States, my family has been hunkered down at home since mid-March due to concerns about spreading coronavirus.  This has meant a cessation of all my children’s activities like dance and soccer.  Therefore, it has also meant cancelled trips for dance competitions and soccer tournaments.

Furthermore, my wife and I have been working from home since returning from an aborted ski trip to Winter Park, Colorado.  There is nothing quite like the ski resort effectively closing for the season a mere two hours after you arrive in town.  It is a real kick in the groin to have to go up and over the Berthoud Pass twice in thirty-six hours.

All of this has already added up to seventeen days of working from home, so two cars have been practically parked for that same time period.  Just my driving alone for those seventeen days would equal more than 350 miles of driving my Nissan Leaf not counting any additional mileage for grocery shopping or shuttling kids.  This demand for transportation has not been shifted.  It has been destroyed.

Along with the demand destruction for transportation is a corresponding drop in carbon emissions as a matter of course.  The dramatically altered commuting habits of Americans and others across the globe have decarbonized our transportation.  It’s not permanent, but it does show that a radically different future is possible.

One of my goals for 2020 was to replace 500 miles of car-centric transportation with human powered transit.  I had hoped to start commuting one or two days a week via bicycle to my job, but coronavirus has had other ideas about how things are going to develop this year.

While I have not been replacing car miles with bicycle miles I have watched the number of miles driven drop precipitously.  For example, during the first two weeks of April I have driven my Nissan Leaf less than 60 miles which includes all of my household’s car transportation to do things like pick up groceries.  Sixty miles is what I would generally average across less than three days during normal conditions.  I guess all of the kilowatt hours from my solar array are going to get shunted onto the grid for someone else to enjoy.  Each day of no car travel in my Leaf is like putting 4 kWh onto the grid for someone else to use.  Maybe it will displace just a little bit of coal.

The upside to this whole shit sandwich of coronavirus, specifically, and 2020, generally, is that we are witness to a different possibility for the future that is a departure from our current path without being dependent upon radical technological change.

The sky is blue because we just stopped driving.

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.

Back to Full Strength

At least in terms of solar photovoltaic production.  Last week I wrote about my solar array having a single panel that seemed to be out of commission for some reason.  I was able to diagnose this via the monitoring platform that is part of my system from Moxie Solar.

Here is what things look like today:

Physical Layour Fixed

You will notice the formerly inoperable panel in the top right corner is producing electricity like a good boy.  The problem was a loose connection that took about five minutes for a tech to diagnose and repair.

Now I can put a few more clean, green electrons back into the grid.

The Importance of Solar System Monitoring

Once a solar system is installed, the local utility has signed off, and the city inspectors give the go-ahead there is a moment of relief as the lever is finally pushed into place.  Once operational, your photovoltaic array sends clean and green electrons through your home’s electrical system and out into the world.  Hopefully.

A lot of monitoring systems give you a picture of the total photovoltaic system.  You can usually see how much the system is producing in aggregate and maybe you get a picture of your production versus consumption.  However, there is a level of system monitoring below this aggregate level that is critically important.

Take a look at the following system layout:

Solar Physical Layout

Notice anything odd?  Look at the top left corner.  Notice the panel producing 0 kWh of electricity?  Something is wrong.  It could be a bad panel.  It could be a bad connection.

Had I not had access to a panel by panel breakdown of production I would never know that one of my panels was not producing.  Now it is easy to request service and it should be a quick fix rather than a laborious process of diagnosing the malfunctioning part of the system.

February 2020 Solar Production and EV Efficiency

The monitoring platform for my expanded photovoltaic array is back online:

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It was only turned on for the last few days of the month, so I do not know how the system performed for the entirety of February.  However, in just four days the system recorded more production than the entire month of February last year.  Granted, the array was under ten inches or more of snow for most of that time last year.

Overall, I ended up nearly even in terms of production versus consumption.  The actual number was approximately 4 kWh “ahead.”  I am figuring that I will end up “ahead” of consumption for most months here on out until January rolls around again.

The crazy thing was that if I had driven a normal amount this month I would have been even more in the black.  Due to a work commitment out of town for an entire week I drove approximately 50% more miles per day on average in the month of February.  Those highway miles added up to a lot of extra driving at a not so efficient clip.

For the month of February I drove ~973 miles at an average efficiency of 4.6 miles per kilowatt hour.  That driving used ~212 kWh of electricity and saved ~1,086 pounds of CO2 being emitted, assuming all electricity was pulled from the grid at an average carbon intensity for my region of the country, versus if those same miles were driven in my truck.

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.