My mission is to live as sustainably as I can and share my actions and ideas so that others may benefit from what I have learned.
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Tuesday, May 26, 2015
My solar lawn mower - still going strong
UPDATE 2022 - I "retired" this mower and purchased a new Greenworks mower performs really well! Back when I built this mower, cordless electric ones were not available and now there are dozens of models. I was able to sell the huge motor for $200 and recycled the lead-acid battery.
Over eight years ago years ago I was inspired by a small article in Home Power magazine in which a guy named Al Latham described how he had converted his standard 22 inch gas powered lawnmower to use an electric motor and battery that he charges from solar. I decided to make my own conversion and have been using it consistently to cut tall grass and weeds in our so-called lawn ever since.
At this time of year I transition from charging the mower from a standard automobile battery charger to using a couple of small solar panels on the south facing roof of my storage shed. These panels combine to a total of 40 W which is enough to charge the mower in one day of clear sunlight. The 10 amp automotive charger can charge it up in a few hours.
Gauges on the handlebar show battery Voltage and Amps drawn when the motor is running. As you can see it draws up to 30 A and can sustain this for 20 minutes or so which gives me enough time to mow a large section of our quarter acre lawn.
In the middle of the summer 20 minutes is about as much as I can handle because this mower is quite heavy with the very large motor and lead acid battery and it becomes sweaty work. Nonetheless, it is a delightful mower to use because it is very quiet and powerful enough to cut through tall weeds.
Maintenance involves sharpening the blade every year and replacing the battery every 2 to 3 years at a cost of $60-$80. So this is definitely more expensive to operate than a gasoline lawnmower, but it has zero emissions and may last significantly longer than one of its gas cousins.
If you want to learn more about the construction of my solar mower, I have a detailed blog on my website with clear instructions on how to build your own.
Saturday, May 9, 2015
Firewood: it warms you twice
wood pile and my workshop building |
Each year I set a goal of cutting 1 cord of firewood from our 2 acre woodlot behind our house. This is just enough to augment the solar/propane heating system for my super insulated workshop,and it is great exercise. As they say; "Firewood warms you twice, first when you cut and split it, and then when you burn it".
woods behind our house in Maine |
As a sustainable guy, I cannot countenance using smelly fossil fuel powered chainsaws so I have two electric chainsaws. One is a 14" lithium battery powered cordless saw made by Oregon:
Oregon CS250 cordless chainsaw |
I also have a Poulan 3.5 hp electric chainsaw that I run on a long extension cord:
Poulan PLN3516F 3.5 hp chainsaw |
bucking logs in to 16 inch lengths photo: Rebekah Younger |
splitting a log photo: Rebekah Younger |
about 1/2 cord cut and stacked |
Fortunately, the weather on the days I have been working has been pleasant and in the 60s. As the weather gets warmer it becomes less enjoyable to work, so I try to get as much cut as I can before the warm weather. When the heating season starts in late September, I enjoy reminiscing about the specific trees that I cut and split as I put them in the wood stove. There is also a layer of satisfaction of knowing that I harvested all of the wood myself. For the house where we use 2 to 3 cords of wood a year, I capitulate and purchase pre-cut firewood that we have delivered. There is still some sweat equity involved in stacking this wood though!
From a sustainability standpoint modest use of responsibly harvested firewood is essentially carbon neutral since I am simply shortening the carbon cycle of trees that would naturally fall and decay thus releasing their carbon. By giving precedence to dead or dying trees, I'm reducing my impact on the natural cycle.
Monday, April 27, 2015
Replacing the anode rod in my hot water tank to extend its life
It is clearly visible at the top of the water heater tank as the only large nut on the top.
Below is a picture of a brand-new rod, and below it what was left of the one that I replaced:
New anode rod |
worn out anode rod |
This water tank has been in service for six years as my solar hot water storage tank, and another six years prior to that it was my primary source of hot water. This should serve as a cautionary tale to anyone with a water heater tank. It is a lot less expensive to replace the anode rod than it is the entire water heater!
Note: due to the low ceiling height clearance, I installed a flexible rod like the one below.
Generally they are straight and measure 24″ to 36″ long, and some are even longer. Your anode rod needs to be sized to match your tank. Here's a link to the one I bought. (as an Amazon Affiliate, I earn from qualifying purchases.)
This is part of my ongoing series that deals with the concept of repairing rather than replacing as a way of living sustainably. One can argue that living sustainably can save you a great deal of money over the long term, and this has certainly been true for my lifestyle.
Wednesday, April 22, 2015
Understanding solar insolation
If you live on the equator you do not see significant seasonal variations in insolation, but where I live at 44° latitude, it varies considerably throughout the year and it is important to understand this in order to correctly predict how much energy one can extract from the sun.
There is a very helpful web calculator produced by PVeducation.org that produces charts of available solar energy (insolation) for given locations. I use this tool to create the animation below that shows the available solar energy in Watts/square meter in 10 day increments for the year at my location of 44° latitude North.
This clearly demonstrates how the available sun hours per day varies significantly at my latitude. The chart below shows the predicted versus actual solar energy produced by my solar array and clearly shows the seasonal variations. The predicted energy was charted using the calculator from National Renewable Energy Labs called PVwatts which takes into account both seasonal variations and local weather conditions. The actual data came from monthly energy production reports from my solar array.
Saturday, April 18, 2015
Repairing - not replacing our microwave oven
Microwave oven with replacement magnetron |
security bit set |
Having removed the cover, it was easy to identify the magnetron inside:
microwave oven inside with replacement magnetron |
magnetron secured with Phillips head screws |
In our disposable economy I realize that I am somewhat heretical in that I firmly believe things should be repaired and not replaced without a thought. I hope that anyone reading this will consider repairing a broken appliance themselves. Not only is it very satisfying to repair something, but it also saved over $100 on the replacement cost of a new microwave oven.
If you are on a tight budget and happen to see an appliance that someone has put out with their garbage, you might want to consider it an opportunity to acquire an affordable appliance with a little repair work. If you are even more enterprising, you could do the repair and then donate the appliance to a worthy cause! All of this is something to consider in the spirit of keeping things out of the landfill.
Sunday, April 12, 2015
Interior storm windows - thermal study
I have installed these interior storms throughout my workshop because the original windows were cheap, single pane, double hung units that are very leaky. When I first closed in the building from being an open barn to a heated space I purchased commercial interior storms, and more recently have added my own handmade ones as well. For every trapped layer of air, an R-value of one is added. So starting with a single pane of glass, by adding a double pane interior storm there are two trapped air layers creating and R-value of two, and by adding a second interior storm I am upgrading my original windows by an R-value of 4 which is very significant.
Fluke VT04 Visual IR Thermometer |
Then I proceeded to take thermal images of the window itself, followed by each of the additional interior storm windows:
By adding my homemade interior storm window I gained 3.6°F and then adding the commercial aluminum framed interior storm window I gained an additional 1.8°F for a total improvement of 5.4°F. While I adjusted my thermal camera to compensate for the low emissivity of the reflective surfaces, I cannot be sure these readings are entirely accurate, but they certainly convey the concept.
My homemade window is framed with 1X2" primed pine lumber with 3/4" spacing between the panes, while the commercial one is framed in aluminum with only 1/4" between the panes. Additionally, the air gap between the glass and my window is between one and 2 inches, while the air gap between my window and the commercial one mounted to the surface of the window framing is around 4 inches. Larger air gaps are less efficient because they can function as a heat pump as cold air flows down at the colder surface and warm air flows up the warm surface creating a circulation.
Saturday, April 11, 2015
Solar collectors and panels explained
A solar collector is a device that absorbs heat from the sun which is then used directly or stored in a tank inside the home. Collectors can be used for both building heating and domestic hot water heating. Here is a very basic diagram showing how it works.
The principle is similar to leaving a garden hose out on your lawn on a sunny day - the water will come out warm. Collectors are much more efficient and sophisticated version of this.
There are essentially two types of collectors. Flat plate collectors are often confused for solar panels because they are large rectangular devices with glazing on the front. Inside there are sheets of black metal heat absorber material coupled to copper plumbing.
The other type of collector is an evacuated tube collector like this:
These collectors have a heat absorber pipe inside something that is similar to a glass thermos bottle. Heat is transferred to the plumbing manifold header at the top. The vacuum glass tube prevents heat loss and improves efficiency.
On my property I use flat plate collectors on my house to heat water, and on my workshop building to heat the building via radiant floor and radiators. Both systems also use small solar panels to provide electricity for the circulation pumps that pump the antifreeze fluid through the collector to the storage tank. Due to the lower cost compared to solar electric panels, both of these systems generally have had a much shorter return on investment than solar electric systems.
Saturday, March 28, 2015
How I eliminated junk mail
Several years ago, I decided to tackle my junk mail issue. My mailbox was filled with catalogs and other junk mail every day and I realize this amounted to an enormous amount of waste despite the fact that I recycled everything. The idea of cutting down trees, printing catalogs and mailing them to a recipient who immediately disposes of them is the epitome of an unsustainable reality and I wanted no part of it.
I took several approaches to eliminating junk mail. First, I subscribed to the TrustedID - one of several direct mail preference services and entered my preferences on their website. This organization effectively handles the rest for you, here is what they say on their webpage:
We act on your behalf to protect your consumer rights and get your opt-outs processed. You can keep track of your opt-outs, and if you receive the mail again, we will follow up. We work with over 8,000 companies — and the largest data brokers — to honor your choices and protect your privacy. We have processed over 25 million opt-outs by over 1.7 million account holders.
The direct mail industry also offers another option known as the National Do Not Mail List. Both are good examples of an industry policing themselves in order to reduce their own costs. Here is how they explain their service:
As direct marketers ourselves, we know that mail-order companies don't want to waste their money sending mail to people who don't want to receive it.
They'll gladly take your name off their lists when they're asked to do so. But with countless mail-order companies doing business today, you just can't contact enough of them on your own to make a difference. The postage alone would cost a fortune!
A similar option is available from DMAchoice.org which also offers an option for reducing junk email.
Incidentally, if you have not already signed up with the National Do Not Call Registry - a service of the Federal Trade Commission, you can reduce the number of telemarketing phone calls that way. I have signed up for that service, but still get solicitation phone calls. The way to eliminate these is to refer to their caller ID and call them back, many of them offer an option of "press 1 to be removed from our calling list", and if not some of them will connect to an actual person who will remove you from their list if you ask nicely. I feel that is important to be polite when asking to be removed - the person you are talking to is not the bad guy here, just an employee.
Finally, when all else fails I made a simple rubber stamp that prints the following:
Of course you can also write this on their subscription form. This is particularly useful when they provide you with a postage free return envelope. All I do is remove the return section, stamp it next to my address and stick it in their envelope. They get the message eventually!
I also reduce mail in general by paying all my bills electronically either through direct debit or paying through the company's web portal.
At this point I can honestly say that I rarely get any junk mail whatsoever. I still do get a few catalogs and mailings from companies I do business with.
According to another junk mail reducing web site: www.41pounds.org: "The average adult receives 41 pounds of junk mail each year of which 44% goes to the landfill unopened" (or hopefully it is recycled). They have more statistics that make the idea of reducing this waste very compelling. They have a $35.00 one-time fee and use $10 to support effective non-profits like Habitat for Humanity.
If more of us took this simple action, we could have a significant impact.
On a slightly different topic, I have also subscribed to Incogni - a service that removes all of your personal information from the Internet. From their website:
Data brokers collect your personal information and profit off it at the
expense of your privacy. Let Incogni help you take back control of your
data, reduce spam, and prevent scam attacks by opting you out of their
databases automatically.
A one month or two months subscription should take care of everything, just be sure to cancel your subscription after two months. After this it is largely unnecessary.
Thursday, March 26, 2015
Conserving water with a circulation pump
The principle is that a pump is installed under the sink that pulls hot water up to the pump, and returns it back down the cold water pipe to the water heater at the press of a button. The 54 Watt pump shuts off as soon as sufficiently hot water is present. Each time you need hot water you just press a button and wait half a minute while the water is sent back to the water heater tank instead of down the drain. The pump shuts off at a pre-set temperature.
This system differs from other designs that constantly circulate hot water through the plumbing to keep it available at all the faucets constantly. I don't recommend that type of system as it actually wastes energy, both at the pump and due to radiated heat loss from the plumbing which acts as a defacto radiator in the walls of your house.
The D'Mand system reduces waste and saves energy in 3 ways:
- reduces the use of our 1500 Watt 240Volt well pump.
- reduces the need to heat water that would just go to waste down the drain.
- reduces waste water entering our septic system.
The installation of the pump is quite simple. After shutting off the water supply and draining the lines to the sink, the faucet shut offs are removed. A tee is inserted, and the shut-off is replaced. Then the 2 flexible lines to the pump are installed onto the new tee thread. This took me about 20 minutes.
I am an experienced plumber so I had no trouble installing the pump. Any plumber would also find this a simple installation.
The challenging part is that an electric outlet is required under the sink. The nearest outlet in our bathroom is off to the right. So I made a run to the hardware store to get a bunch of Wiremold (surface wiring conduit) parts. Then I added a breakout box on top of the existing outlet and ran Wiremold channel across and down into the space under the sink where I installed a new outlet for the pump. This part took over 3 hours!
I also made an attractive circular white acrylic switch plate, and used a stainless steel push button.
Once the button is pressed the pump turns on immediately and shuts off automatically as soon as it senses hot water at the pump. This saves several gallons of water that would otherwise run down the drain, and reduces the usage of our tankless water heater. In our home the cold line returns to the bottom our solar storage tank where the sun heats it up for free.
Before the pump was installed it would take 80 seconds for the hot water to arrive, now the pump brings it up in about 50 seconds after pressing the button, and the water runs hot from the faucet within a few seconds. They also make a motion sensor that will turn the pump on automatically when you enter the bathroom (or kitchen). Here is the accessories page.
Monday, March 23, 2015
Reviewing our renewable energy and efficiency investments.
We use propane to heat the house and also for cooking, clothes drying, and water heating. The chart below shows our annualized usage and cost for propane per heating season. As you can see we have reduced our use of propane by about 50% over the years. The biggest impact was the solar water heating system installed in 2006.
Not factored into our relatively low propane costs is the fact that we burn up to 2 cords of firewood per year at a cost ranging from $300-$500 per year. In 2014 we spent $425 for firewood which brings our recent total heating cost to a little over $1400 which is less than half the Maine state average for home heating costs.
Some of the things responsible for our diminishing usage are:
- Improved basement insulation added to exterior concrete walls.
- Tightening up the building envelope by foam insulating air gaps around window and door framing.
- Adding interior storm window panels and closing honeycomb insulating shades in the cold winter nights.
- Weatherstripping around exterior doors and improving attic insulation.
Thanks to the solar power system I installed, our average electric bill would be around $10 if we did not have the Chevy Volt electric vehicle which adds approximately $45 per month to our monthly bill.
The $45 average monthly electric cost to charge the Chevy Volt is reducing our gasoline usage by about 26 gallons for that vehicle since we drive in electric mode about 60% of the time. (The remaining 40% are driven in “range extender” mode at approximately 40 mpg.) And since a large percentage of the charging power for the Volt comes from our solar array in the summer, we are driving for largely free and carbon neutral during those months.
One can look at all of the investments I have made in reducing our energy footprint in terms of return on investment. In actual dollars most of these investments have already paid for themselves, such as the solar hot water heating system I installed in 2006 which according to my calculations paid for itself in approximately 4.5 years and will save us an estimated $11,000 over 25 years: