Tag Archives: emissions

How Long Will the Battery Last in My Cordless Electric Lawn Mower

This weekend was the first time that I actually used my new cordless electric mower to cut my lawn.  Prior to this I had tested the mower to ensure that it worked—in case I needed to return it since I bought it on mega discount at the end of last year’s outdoor season—and to make sure that the third party batteries I purchased online worked as well.  Nothing would have been more disappointing then heading out to mow my lawn and hearing nothing.

My yard is just under half an acre, but not all of that is grass.  A large portion is the house, driveway, sidewalk, etc.  There are also quite a few trees and landscaping with more on the way this summer.  I do not have an exact figure, but it is a large lot.

Most of the reviews of the cordless electric mowers that I have seen were conducted on small yards in places like Florida and California.  These are the kind of yards that take twenty minutes on Sunday morning to mow.  In the case of my yard it is more like 45 minutes to an hour depending upon mowing direction and how many foam darts I have to pick up.

To power the lawn mower I purchased two third party 6 amp hour batteries.  These batteries were decently reviewed and I hoped that six amp hours would provide me enough extra capacity to mow my lawn without stoppage.  Originally, the Ryobi lawn mower came with a single 40V 5 amp hour battery that I am going to use with a battery electric string trimmer.

Well, the first battery—from full charge until the mower stopped cold in its tracks—lasted just over thirty two minutes.  This is a far cry from the forty five minutes I had read that a five or six amp hour a battery would last.  However, I was using my mower’s self propelled feature so there is probably a decent hit to run time caused by the extra oomph it provided.  Given how light the mower is the self propelled feature is more of a “nice to have” than a necessary evil.  The next time I am going to forgo using that feature on the totality of my lawn to see the impact on battery life.

The second battery lasted until I completed my lawn approximately 20 minutes later with no fade in power.  That is approximately 50 minutes of run time with one battery completely empty and another with electrons in the tank, so to speak.  My plan is to keep track of the batteries’ performance across the season to see how operator error, weather, and cutting conditions impact performance.

Lawn mowers are pollution bad actors.  The numbers are hard to pin down because there is so much variation—small engine, riding mower, CARB compliant, etc—but there is no doubt that an hour of mowing is worse than an hour of driving a car.  It’s not just the carbon dioxide that is emitted by small engines that should concern you the most.  These engines are veritable factories for compounds like carbon monoxide and nitrogen oxide.  Nitrogen oxide, along with its friend sulfur dioxide, is the bad chemical compound that combines with atmospheric compounds to make acid rain.

For the season, I have eliminated ~50 minutes of gas-powered lawn mower operation with a solar powered battery electric lawn mower.  Stay tuned for the ongoing accounting of how much I “decarbonized” my lawn care routine.

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.

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.

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.

First Step in a Path Toward Deeper Decarbonization

Once you have purchased an electric vehicle—in my case a used 2015 Nissan Leaf—and installed solar panels—in my case a total of 24 panels for a nameplate capacity of ~7.5 kWh—you are left with a question: how do I further decarbonize my household?

If you live in a single family home in the United States there are a surprising number of places where fossil fuels are being used on a daily basis.  Most home owners do not really consider these sources of carbon emissions.

Consider the lawn.  Anyone with an inkling of environmental conscience understands that the turf grass monoculture that dominates our landscape is essentially a hellscape of inappropriate plants, harmful chemicals, and energy intensive maintenance.

In my household we have abandoned the chemicals and I am ripping out sections of turf grass as often as I can in order for it to be replaced with perennials suited for my region.  However, I am left with some amount of turf grass and social expectation that this grass be mowed on a semi-regular basis.

Trust me, I have pushed the bounds of both social expectations and legal ramifications over the years by allowing parts of my lawn to go weeks without seeing the spinning blade of a lawn mower.

Nonetheless, I am bound to some degree to maintain a well-manicured lawn.  As a good suburban homeowner I spent the last nine years mowing my lawn with a traditional gas powered push mower.  I dutifully filled it up with a small amount of ethanol free gasoline every few weeks and spent about an hour clipping my grass down to the maximum height setting.

Thankfully, a series of mechanical mishaps aligned with my desire to rid myself of this pollution spewing beast.  How much pollution does a mower release, you ask?  It depends upon the source and methodology, but according the EPA lawn mowing accounts for up to 5% of the United State’s total air pollution.  Not to mention the millions of gallons of gasoline that are spilled filling mowers.   Add in the oil required for four stroke engines and you have a lot of fossil fuels being consumed to keep our lawns high and tight.

Now, I could have rolled old school with a reel mower as someone will surely point out.  I would also ask that person if they have ever mowed more than a few hundred square feet with one of these contraptions.  Seriously, another eco-minded neighbor bought one and every household with an interest tried it once.  Reel mowers are the Zima of lawn care.  You try it once and never think about it again.

Strolling the aisles of my local Home Depot—an activity one is likely to engage in when waiting for your child to complete soccer practice—I noticed a clearance sticker on a Ryobi cordless electric mower.  Now was the time to jump on the electric lawn mowing bandwagon.

For less than the cost online of a regular push mower—battery electric or ice—I took home a battery electric self-propelled mower.  The 40V mower came with a single 5-amp hour battery.  If I believe the online reviews this battery should provide about 45 minutes to 1 hour of cutting depending upon usage.  We shall see.

Additionally, I purchased an extra battery online.  The cool thing about the 40V Ryobi tool line is that with such a large installed base there is a healthy aftermarket in third party batteries.  I was able to get a compatible battery rated at 6-amp hours for less than $80.  With two batteries I should have more than enough capacity to complete mowing my lawn.  Again, we shall see.

For the first time in forever I am looking forward to the beginning of lawn care season if only to see how the electric revolution applies.  The march toward a deeper level of decarbonization carries on.

Friday Linkage 2/14/2020

Well, New Hampshire may have finally cooked Joe Biden.  If it was not his primary night performance it may well have been him calling a woman at a meet and greet a “lying dog faced pony soldier.”

The thing that gets me about Biden is that he did not run in 2016 when he was the sitting vice president.  He did not jump into the race until relatively later this time around.  His supporters do not seem so much enthusiastic about his candidacy as they seem obliged to support the man.

Maybe he should spend some time commiserating with Corn Pop about the good old days.

On to the links…

Global CO2 Emissions “Flatlined” In 2019, New Report Claims—The methodology might be in question, but maybe there is hope for us humans yet.

Drilling Under Slickrock Is Dumb—I take that back.  Most humans appear to be idiots.  Especially the humans behind oil and gas drilling.  Their entire worldview is defined as “drill everywhere and drill now.”

Is The US Coal Industry Completely Burned Out?—Do not weep for the coal industry.  We will be picking up the pieces from this industry’s destructive sweep for decades, if not centuries to come.

More Electricity From Renewables Coming To Australia—Every additional megawatt of renewable energy is a positive step forward.

The Biggest Municipal Solar Farm in the US Is Coming to…Cincinnati?—Red state, blue state…it does not really matter.  People want access to renewable energy.

Arizona and the Momentum of 100 Percent Clean Energy—Arizona is not the most friendly state for renewable energy despite the abundance of sun and open space.  If a state with retrograde politicians like Arizona has the momentum to get to 100% renewable energy we know that the worm has turned in our favor.

Sales Of Gasoline & Diesel Cars Fall In Australia As Sales Of EVs Rise—It’s a zero sum game in a market that is not growing.  If someone buys an EV that consumer is not buying an ICE.

This Ultra-Strong Nanomaterial Could Cut Carbon Emissions — and it’s made out of garbage—If this is real then it is really cool.

The Low Price of Freed Parking—Just think about it this way: If you work in an open concept or cubicle office environment it is extremely likely that your automobile is allotted more physical space than you are given.  What is the price of parking now?

The Hidden Biases that Drive Anti-Vegan Hatred—There is a lot of vitriol thrown at the direction of vegans.  Just witness the late Anthony Bourdain comparing vegans to Hezbollah.

No One Can Explain Why Planes Stay in the Air—These kind of articles just freak me out.

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.