My new 27 inch Greenworks cordless lawnmower

 

A year ago I purchased a small 20" Greenworks cordless lawnmower to replace the old 22" gas lawnmower that I had converted to electric many years ago, here's a link to my blog post about those mowers.

Last year my friend Roberta purchased a small property in the nearby town of Bath that has a very modest lawn and I encouraged her to get a cordless lawnmower.  This spring she went over the top and bought a giant 27 inch Greenworks machine.  This beast runs on two huge, heavy 80 V batteries and is also self-propelled.  I went over to help her un-box it and try it out and she quickly realized it was much bigger and heavier than she expected and massive overkill for her small lawn that is not much more than 1000 ft.².

So I proposed a trade, I would give her my 20 inch mower plus some cash and she would give me her new mower.  We are both very pleased with this exchange since the mowers we now have are perfect for our properties.  My lawn area is over half an acre and this big new mower is a joy to use especially in the heat of the summer when the self-propelled feature is a real blessing.  I also have a cordless weed wacker, hedge trimmer and chainsaws that I use a lot.

In the 20 years or so that I have lived on this quiet dead-end road in Maine I have encouraged many of my neighbors to embrace more sustainable lifestyles which includes buying an electric car, subscribing to solar power, and hopefully soon they will be replacing their stinky old gas lawnmowers with electric ones.  Some of them already have other cordless electric yard tools.

Scientists are warning that we are crossing the tipping point with the climate crisis and there may be no turning back.  This is why I do what I do!  I carry a constant awareness of future generations and the massive impact the climate crisis will have on their lives.

Failed septic system and energy monitoring update

In late April my septic system failed.  This constituted a household emergency and I had to scramble to get a new system designed and installed.  For those of you in the city unfamiliar with septic systems the sewage comes out of the house and goes into a large underground concrete storage tank that is typically 1000 gallons for a two bedroom house like mine.  Solids settle out in the tank and the liquids come out the other side and go to a leach field.  I have been doing proactive maintenance and having the tank pumped out every three years, but apparently the system was just so old that it eventually failed.  Where the pipe enters the leach field there is a distribution box that spreads out left right and center to feed perforated pipes buried under the ground.  When I exposed my distribution box I found that it was completely plugged up with gunk:

Distribution box opened up

In fact the entire pipe from the septic tank to the field was also plugged up.  From what I can tell this system was installed in the 1970s before the state required that records be maintained in the state house and local towns.  So I immediately hired a soils expert to design a new leach field ($550) which required him to come out and survey the land and test the soils figure out how big and what type of septic leach field to engineer for my location.  I took his design to my town office to get a permit approved for the construction of a new system and then put the design out to bid to local companies.

It turns out that my small town of Woolwich, population around 3300 has three family-owned  earthworks companies.  I ended up hiring Creamer and Sons Landworks.  Joe and his two sons started work in early June and it took them about seven working days to complete the installation, here are some photos:

Creating a berm around the Leach area

Crushed rock laid in.  The leach field pipes sit on top of this gravel.

They began by hauling off all the surface vegetation and dirt which they could later screen and process and bring back. Then they built up a berm out of sand and then loam and then installed the leach field inside the berm by laying down sand, then crushed rock then perforated pipe, then more sand, and then finally a layer of loam.  The town code officer approved the first step of the construction and later came back to approve the crushed rock installation as seen above. 

There were 5 ton and 10 ton trucks coming and going right through the middle of my lawn and at the end they put everything back with new dirt and grass seed and my new lawn is growing back in.  This whole project cost me over $21,000 and I had to refinance the house to pay for it.  They did an excellent job and I'm sure the system will last longer than I will!  Click here to see a blog post that links to two videos I made about the entire process.

Between the initial failure when I first had my septic tank pumped out to give me some time I had to pump it out a second time.  When they pump out just liquids they charge less - $250 compared to $350.  My housemate and I were able to dramatically reduce our usage of water by approximately 50% in order to defer further costly pump outs before the new system could be installed.

From an energy monitoring standpoint, I was able to clearly determine that we had in fact reduced our water consumption significantly by looking at the energy consumption of my 1500 W well pump which is down about 100 feet below ground in the granite.  Here's a screen from my Emporia energy monitoring app (see my previous post about this here) showing daily well energy consumption before and after extreme conservation measures:

Well pump energy

It looks like we reduced water consumption by approximately 50% and us guys were able to pee outside a lot since my property is rural and private.  Like many rural male Mainers I pee outside quite often anyway since it's an 80 foot walk to the house from my workshop that does not have plumbing.

After the septic system was installed I needed to run a sprinkler for an hour or so every evening to water in the grass and clover seeds I planted.  The contractors put grass seed and straw in the area where they replaced the existing lawn, and I elected to seed the whole septic area with white clover which is lower maintenance and good bee habitat. Clover is also a good nitrogen fixer that out competes weeds and grass.  

leach field planted with clover

sprinkler, and lawn  growing  back in

 The daily energy chart below shows a dramatic increase in my well pump usage to keep all that new loam nice and wet.

Well pump after septic installed

If I did not have a solar power system (38 panels producing a peak of over 8 kW) I would see a significant increase in my electric bill to run that pump so much.  Starting in mid-May, my solar energy production exceeds my needs and the utility allows me to bank my kilowatt hours as credit that I can use in the fall and winter.  The bottom line is that it is costing me nothing to run my well pump for hours!  The weekly energy chart for my entire property below shows that I was using a lot of energy to run my two heat pumps in the winter when I have much less sun here in Maine at the 43rd parallel.  As I get more sun and the weather warms up reducing the need for the heat pumps, eventually the solar starts producing a surplus in May.

weekly net energy consumption

My electric bills spiked up over $300 for a few months in the dead of winter mostly due to the heat pumps that I installed, but this is a lot less expensive than heating with propane as I had in the past.  But then from May through October, I will pay the utility just a connection fee of around $13 a month and I will use my accumulated credits to cover my energy use into November and December hopefully.

You can see a video about my recent installation of additional solar panels on YouTube: https://www.youtube.com/watch?v=hl8r-gZupfE

 I find myself checking energy use on the Emporia app every week or so to see what is using the most energy.  The biggest energy consumers are my (self installed) heat pumps, one in my house, and one in my workshop.  Here's a weekly chart of energy for my house heat pump:

It was working hard during the winter to keep my living/dining room area warm when temperatures remained below freezing for weeks at a time.  As you can see, energy use plummeted in May when I often shut it off completely, but now in late June I am turning it on for cooling but it uses a great deal less energy for that.

Effective tick control on a budget

 It's spring in Maine and the crocus and daffodils are starting to come up and it's time to start thinking about tics.  Last year I purchased a product called Thermacell Tick Control:  (Click here to purchase on Amazon - As an Amazon Associate I earn from qualifying purchases.)

It's basically a cardboard tube with cotton balls soaked in permethrin - the stuff that kills tics on contact and you typically spray it on your clothes.  You get six tubes for roughly $20. You tuck these tubes into nooks and crannies in the yard around your home.  The theory is that small rodents will use the cotton as nesting material and get permethrin on their bodies which will kill tics on contact and reduce the breeding population.  When I used this product last year, I saw dramatic reduction in the amount of tics I found on my body.  While I did find a few ticks on me in the early spring, there was almost nothing after that and I walk around in the tall grass on my property quite a bit.

 I realized when I was opening a vitamin bottle recently that I could use the cotton packing and just spray it with permethrin myself.  This stuff is really nasty, so I took it outside and sprayed it on to the cotton on-site and then tucked it into the bottom of my woodpile.  I wore surgical gloves when I did it because I don't want to get any of that nasty permethrin on my hands.  I have done this a few times now and every now and then I will see bits of cotton tucked into different places in the bottom of my woodpile and elsewhere, so I know that chipmunks and mice are using it.

 I recently added one more 375 W solar panel to my south facing array.  I made a YouTube video that documents the process in detail to show how relatively simple it is for anyone with building skills to install a solar panel:

After installing a heat pump in both my house and workshop buildings I was hoping that my energy costs would be the same or at least go down a little.  It doesn't seem to be working out that way despite adding these panels, but the heating season isn't over yet.  My first electric bill was over $300, as was the second one.  But given that my propane costs for heating season run over $1000, I'm hoping that I'm going to come in a little lower than that.  

The primary reason for doing all of this is to get off of fossil fuels so I'm very happy with that.  and, what energy I don't generate with solar comes from a solar farm here in Maine, so I am essentially carbon neutral other than the modest amount of propane I use for cooking, clothes drying, and water heating.  eventually, I will tackle at least two of those issues and convert to electricity.

Now I am pretty much maxed out for solar panels, so there's not much room for improvement.

Home electrical energy monitoring with Emporia

 

Click here to buy

As an energy efficiency maven, I am always interested in looking for ways to monitor my energy usage.  The more I can learn about how my energy is used the more I can figure out ways to conserve.  Over the years I have experimented with different kinds of energy monitors and just recently discovered this very affordable home electrical energy monitoring system.   

An Emporia system like the one pictured above sells for around $160.  (click here to purchase one - As an Amazon Associate I earn from qualifying purchases.
This system allows you to monitor 16 separate circuits in your circuit breaker box.  A smaller 8 circuit system sells for around $100.  I have installed two of these systems, one in my workshop that also feeds through to the house and a separate system in the main breaker panel of the house.  

They also sell smart plugs that can be controlled by your home automation system.  These also connect into the monitoring system so you can monitor energy for specific plug in items:

I have ordered one of these to check out and might use it to monitor and control my AV system via my Alexa app and Echo devices.

Having recently installed heat pumps in both buildings and also added 5 375 W panels to my solar array, I wanted to see how everything was working out.   (I was a little shocked that my first electric bill since installing the heat pumps and upgrading the solar power system came out at over $250! - but my main reason for doing this was to stop using propane for heating both buildings and I think it will come out less expensive per heating season).

Installation is surprisingly easy so long as you're comfortable opening up your breaker panel and I had absolutely no trouble getting the system working within 1/2 an hour so.  below is a picture of my main breaker panel with the Emporia system installed:

Yes, I know, it looks messy, but it is all safe and functional.  The system includes two very large 200 Amp current transformers at the top that measure all the power coming into the building from the utility:

Then multiple small current transformers clip over the wires to the circuits that you want to monitor:

These are then all plugged into the monitor device that sends signals out via Wi-Fi. There is an antenna that pokes out through the wall of the breaker box that you can see in the bottom of the image:

A few minutes after installing the app, I could see real-time energy data showing up in the form of graphs and lists of circuits that I had named.  I particularly like that you can configure it to record power from your solar power system.

Below is a screenshot from my phone showing my EV charging station feeding some power to my Chevy volt to keep the battery warm.  The temperature is hovering around freezing in late December here in Maine and my car draws power in small bursts to keep it warm in the winter when it's not actually charging.  While I knew this was something that was going on, it is educational and informative to see exactly how much power and how often it is used to keep the car battery warm.  Keeping the battery warm dramatically extends its useful life.

 

 

This screenshot shows a weeks worth of data for my house.  Clearly, the heat pump is the biggest energy user followed by a small 1.2 kW electric heater used in my small bedroom at night (the master bedroom is heated by propane).  Solar power in this breaker panel comes from one 240 W solar panel mounted on the side of the house.

 This screenshot shows daily solar energy produced by my entire solar array of  36 solar panels:

And this screen shows the hourly solar output for the last couple of days:

Yes, the solar days are quite short in December here in Maine!

It is said that knowledge is power, so I am feeling quite empowered by all of this useful information!   I find myself opening the app on my phone several times a day and poking around through all the information to see what I can learn.  It is particularly interesting to watch the real-time chart updating every second to see the energy cycles of things like the heat pump, well pump, solar power system and EV charging station.

 

Removing old solar thermal collectors

5 new 375W solar PV panels

A few weeks ago I completed the DIY installation of a mini split heat pump system in my workshop.  The system essentially replaces the solar heating system I built that used to use four large 4' x 8' solar collectors on the south facing shed roof of my workshop.  

I had installed the solar heating system 20 years ago and it had offset the use of propane over the years.  But that system could not begin to compare with the efficiency of electric heat pumps, and it is my goal to get off of fossil fuel as much as possible. The system used a few hundred gallons of propane last year.  Over the years I had learned to optimize the use of that system which originally used over 800 gallons a year, in the last two years it has been below 300 gallons.  You can see historical records of my propane consumption on this page of my blog.  The problem with fossil fuels is that their prices are unregulated and the cost of a gallon of propane has nearly doubled over the last 20 years.  

The propane tanks will remain in place to feed my automatic standby generator which is a necessity here in rural Maine.  Eventually I hope to replace that with a battery system since I can run that generator up to 7 days cumulatively in any given year due to extended power outages from storms etc.

The new REC brand solar panels are rated at 375 W each with a total theoretical maximum capacity of around 1800 W.  So far, I am seeing a maximum output of a little over 1400 W at noon at this time of year.  I don't have enough energy data for the new heat pumps to know whether this will completely offset the energy required to operate them.  But I am hoping it will.

 

mounting rails installed

inverter installed

I purchased a complete kit from the altE store in Massachusetts.  I simply called up my account manager, Ben and asked him to spec out a system that could produce close to 2000 W and cost less than $2500.  He specified everything that I would need including every single nut and bolt and it came in at around $2000.  I drove down to Massachusetts (a three hour trip) with my friends pickup truck to get all the equipment.  This includes five brand-new IQ7A micro-inverters made by Enphase.  These are state-of-the-art seventh generation devices that convert the solar panel power to 240 V that feeds right into my building.  (My original system used the M190 model inverter which was their first product over 10 years ago and 8 of those 30 units have failed over the years but were replaced under warranty).

I am so familiar with installing systems like this that I didn't glance at any documentation because it is so simple and plug-and-play for someone with my experience. 
The sequence involves:

• installing mounting rails
• mounting the micro inverters to the rails and connecting them to the umbilical
  
• running wire from the breaker box to the roof
• Mounting and connecting the solar panels

What could be simpler!

last year my solar power system provided all the power for my property from June through October. you can see historical statistics of my solar power system here.  I'm hoping these added panels will get me close to net zero.  Time will tell!

Here's a video I made about this whole project:

 

I installed another heat pump, this one for my workshop

 

I have installed a multi-zone heat pump for my workshop.  This was another DIY MrCool installation similar to the one I did for my house back in March except this one is a bit larger and has two interior air handlers, one for my office, and one for my downstairs workshop space.  It also has connections for a third air handler if needed. 

One of the slightly annoying things about these DIY packages is that the line sets that connect the interior to exterior units come in fixed lengths of either 16 feet or 25 feet.  I ended up with far more than I needed which explains why it is all coiled up against the wall next to the unit in the picture above.  It's not the worst thing in the world.  I only needed about 12 inches between the condenser and the interior air handler, and had to coil 16 feet of line outside, I imagine this compromises efficiency slightly, but I'm not too worried about it

I mounted  the condenser high on the wall under my carport.  This will keep it out of the heavy weather and is over 7 feet high so I can park underneath of it.  The installation was relatively simple, I just needed to cut a couple of 4 inch holes through the wall to run the plumbing through and everything else was just mounting parts inside and out.  The instructions are clear and very comprehensive, but having installed one of these already, I barely needed to look at them this time.  

The condenser is very close to my circuit breaker box inside the building so the 240 V wiring was quite short and easy to do.  The only challenging part was getting that huge heavy condenser mounted on the wall brackets.  I borrowed my friends pickup truck and he and I lifted it in stages onto the truck bed and then up onto sawhorses and so on until we got it high enough to lift it onto the mounting bracket.  I actually used the pickup truck as a raised work surface for all of the final connections and wiring, it was really convenient to be at the right height.

Here's a photo of the small air handler in my office which is more than sufficient for this small room and heats it up quite quickly (and also cools it handily in the summer).   

Downstairs in my workshop the large air handler mounts right near my wood stove which is my backup heat source.  

This system cost me almost exactly $3000 in parts and I expect to get a federal tax break of $300 per installed heat pump which is a real plus.  If I had to pay someone to do this insulation it would've cost way more than double what I spent.  Probably over $8000.  While this type of installation is not for the faint of heart, anyone experienced with building construction and wiring should be able to do it without too much trouble.

I have decided to take down the solar thermal heating system that I designed and built 20 years ago since it is no longer needed and is certainly not as efficient as heat pumps are.  In my next post I will show the process of removing the solar collectors and replacing them with 1800 W of solar PV panels which should be more than enough to offset the power consumption of these two new heat pumps.

Another mini Energy Recovery Ventilator for my home

Back in 2014, I installed a small TwinFresh Comfo Energy Recovery Ventilator (ERV) in my living room at a cost of about $500, and later added one in the master bedroom.  

TwinFresh Comfo heat recovery ventilator

These ventilators bring in fresh air without losing heat in the winter (and also without losing cool air in the summer).  The main reason for installing these units is that my house is so tightly sealed that there was insufficient air exchange to be healthy.  I determined this after doing a building energy audit that included a blower door test from which I learned that the total leakage area of my entire house was about 122 in.².  This means that the air changes per hour were down less than 3 ACH which is considered the low threshold for healthy indoor air. 

Since then, I have tightened up the house significantly.  This summer I had been noticing how the air in my small bedroom felt stale after I installed the air conditioner in the window and sealed up the other window.  With the door closed, there is no fresh air exchange at all in that room which is why I decided to add an ERV to that room.

These clever units work by removing air from the room and sending it through a honeycomb ceramic heat absorber.  Then the fan then reverses and brings fresh air in that is warmed by the heat absorber.  In my tests, I concluded that these units are about 97% efficient when the outside temperature is around freezing and indoors is in the mid-70s Fahrenheit. 

The ventilators I installed previously cost me around $500 - a search for "TwinFresh Comfo" will find varoius sellers offering prices ranging from $450 to over $700.  

This this time I did some research and found that they are available from Alibaba for significantly less,  I paid $185 plus ocean freight shipping  of about $58 and it arrived about five weeks later.  The unit was well packed and comes with clear instructions and appears to be very well made.

 

Well packed!

 Vitronic product photos:

The Vitonic brand appears to be functionally identical to the more expensive units in almost every detail except for the exterior vent cover.  Actually, the remote control works a great deal better than those other units!

Installation is relatively simple, I just cut a 6" hole in the exterior wall and installed the vent and tube through the wall from the outside and then mounted the interior bracket for the inside unit.

 

Cutting 6 inch diameter hole inside

Fan unit installed

 

External vent installed and caulked

There is a three button control panel on the unit itself, but it is the remote control that one generally uses.  This remote is identical to the previous units I had used except that it seems to use radio rather than line of sight infrared which means it has a range of more than 20 feet.  The other remotes only work within a foot or two which was very disappointing.

The remote features include three basic fan speeds: a night mode where the fan automatically drops to the lowest speed when the room is dark and three different airflow options, in, out, and bidirectional (energy recovery mode).  It is helpful to have a vent that can remove air from the room - or bring in fresh air in case of a strong odor.  It also offers three levels of humidity control and I have absolutely no idea how this is accomplished.  But it is this feature that distinguishes an energy recovery ventilator from a heat recovery ventilator and makes it more efficient and usable in humid situations.

I would only recommend installing heat (or energy) recovery ventilators if you are certain that your house is sealed up so tightly that air exchanges and air quality suffer.  The only other option for tightly sealed houses to install an entire heat recovery ventilation system which requires running ducts throughout the house and a large central blower unit that would be typically mounted in the attic or basement.  The cost of this type of system as a retrofit is prohibitive and can result in unsightly ducts everywhere, but it makes more sense when you're building a new home.

my new E-bike

I had given up bicycle riding about 20 years ago when I moved to Maine where the roads all around me are 2-lane blacktop's with cars that whizz past you and the hills were more than I wanted to handle on my old 10 speed.

I recently saw an ad online for an E-bike that intrigued me because the price seemed too good to be true.  I had assumed that all e-bikes started at around $1500 and I've heard that you can spend thousands of dollars on them.  After doing more research I found one that I purchased for $640 which I considered affordable enough.  Including tax and delivery I spent about $750 and have added a number of parts to it including speedometer, blinking safety lights, gel seat pad, water bottle etc.  (Click here to purchase this bike - as an Amazon Associate I earn from qualifying purchases.)

This bike is made by a Chinese company called Ancheer is considered a best buy for affordable yet high quality construction.  While it is quite heavy at 60 pounds it accelerates amazingly well using its 250W motor and 8AH 36 V battery.  I can use either pedal assist mode in three levels of power or full E-bike mode using the throttle much like a motorcycle.  The range is impressive allowing for up to 30 miles in assist mode and 20 miles in full electric mode (all presumably on relatively flat terrain).  It has 26" wheels, front and rear shocks, a Shimano gear set, disc brakes, fenders, and a headlight and beeper.  What more could you ask for!

The other cool thing about this bike is that it folds down quite small so that I can lift it into the back of my Chevy Volt and drive off to fun locations for bike riding:

I have already put over 30 miles on the bike on all kinds of terrain from hilly backroads to extreme off road and could not be happier with it.  The idea of riding 20 miles an hour with very little effort and using the motor to make it easy to climb significant hills is so delightful.  While I am quite fit at age 66, I see no reason to or desire overexert myself if I just want to go for a bike ride.  There is nothing quite like getting on the bike on a hot humid summer day and getting up to speed very quickly - with no effort - but feeling a very delightful cooling breeze at 15-20MPH.

Yesterday my friend and I put both his bike and mine on the bike rack on back of his car and drove up to Camden Harbor here in Maine.  It is a spectacularly beautiful area with relatively quiet back roads.  I had to keep holding the bike back to allow my friend to catch up on his 10 speed.  Often I would zoom to the top of a hill and wait for him at the top.  Here's a view from the top of a small park overlooking Camden Harbor.

And of course all the energy needed to charge the battery comes from my solar power system so it is a 100% green bike.  I get so much joy from riding this bike that I go out as often as I can, and I do get some exercise using it!

 

 

 

 

New cordless electric lawn mower

My original solar lawn mower built in 2005

Back in 2005 I converted my neighbor's dead 22 inch Craftsman gas lawnmower to run on a 12 V electric motor using a deep cycle lead acid battery.  It has lasted 11 years and was crazy powerful.  I have had to replace the battery three times in the intervening years at a cost of about $80 per battery plus a $5 fee or recycling the old battery. Back then there were no cordless electric lawnmowers available and due to my commitment to reducing my carbon footprint, this was the only option I could come up with for mowing my lawn.  That mower was charged from solar panels on my shed roof.  You can read more about the construction of it on my blog here.  At 95 pounds, it is kind of a beast and in the peak of summer summer becomes tiring to push around for 20 minutes - fortunately the battery only lasts 20 minutes or so.

old vs new lawn mowers

 
Over the last several years, almost a dozen companies have introduced cordless electric lawnmowers and last year I started to review them.  The technology has come a long way!  What I find interesting is that there are two newcomers building cordless yard tools, Greenworks and EGO that are both very highly rated.  Cordless lawnmowers are also made by many of the established tool makers like Makita, Black & Decker, etc.  So this spring I did more research and winnowed my choices down to one of those two makes and settled on the Greenworks based on price ($400), size (20" cut width), performance and versatility.

There are several things that are unique about this cordless lawnmower:

• It has slots for 2 batteries and switches from one to the other when one runs down. (It comes with a 4AH and 2AH batteries).
  
• There are inexpensive secondary market batteries available for it with higher capacity than the manufacturer's batteries.
  
• Run time with both batteries installed is estimated at about an hour.
• It has 2 smaller sized blades rather than a single 20" blade.  
• It weighs about 40 pounds which is much lighter than most gas mowers or my previous one which weighed about 95 pounds.  It is so light that it almost feels like a toy until it cuts through the heavy grass like a champ.
  
• It increases its power/speed automatically when it hits heavy grass.
• Cutting height is set with a single lever.
  
• It can be configured either for mulching or a grass catcher on the back.
  
• It is almost as quiet as my previous mower, and much quieter than a gas mower.  It has a very high-pitched whine from the dual motors that my neighbor thought sounded like a drone flying overhead until he came by to see it.
  

old vs new

I have already stripped the old mower for parts.  It turns out that the 3/4HP motor if purchased new today would cost more than the new mower.  So I've listed it on eBay in the hopes that I can sell it for at least half the current retail price.  That big honking gray motor weighs in at 31 pounds so it will be expensive to ship!

The new mower is still solar powered because all of my power comes from solar energy either from my solar panels or the solar farm that I subscribe to.  As Kermit the frog stays: "It's good to be green!"