Solar-Powered Transportation Comes To the Great Plains
By Bill Moore
So the headline is a bit exaggerated! I admit it. But as an ancient Chinese proverb says, every journey of 10,000 leagues begins with a single step.
And that's about what my new solar recharging system is; a first step, but I am getting ahead of myself.
Let me take you back 12 months when I ordered my electric bicycle. I wanted to make a statement, regardless of how small, that I could replace some of my car trips with an electric bicycle. So, I ordered a Currie Technologies folding model.
It took a couple tries to get the bike ordered after UPS demolished the box the first bike came in. The driver suggested I not take deliver, so I didn't. Eventually, the bike arrived without any apparent exterior signs of abuse. I signed the acceptance order and slid the box into the garage. There it remained unopened for several weeks until the weather warmed.
On that glorious Spring day, it took about an hour for me to assemble the bike, which comes neatly folded with everything but the motor pre-assembled. I simply had to unfold the frame and steering column and lock them in place. The motor took a bit longer, but wasn't beyond my meager mechanical capabilities. The battery comes already mounted on a rack above the rear wheel. To recharge it, you separate the connectors between the battery and the motor, taking care to plug in AC/DC charger into the battery and not the motor. Using 110 volt household current, the bike was fully charged by late in the afternoon.
As it was getting dark, I took my first spin on electric power and was hooked. It was -- and still is -- incredibly fun as I went around and around the cul-de-sac in front of my house, the little motor humming as I applied power using the thumb control mounted on the handlebar.
Since that time, whenever the weather and the errand permits, I jump on the bike and with electric-assist, peddle merrily to the grocery store, the post office, the hardware store, the bakery, the barber.
For example, today I needed to pick up a copy of our state tax rate tables from the post office and buy some manila folders at the Office Depot better than a mile away. I used the bike to make the trip, going first to the office supply store and then to the post office on the way back. My legs got a good workout even with electric assist, but having that little electric motor back there made all the difference in the world between enjoying myself or suffering through the experience. Despite the fact that I regularly walk about 10 miles a week, riding a bike seems to use a different set of muscles.
All the time I was riding my bike last year, I kept thinking how cool it would be to use sunlight to recharge the battery instead of the grid, which here in Nebraska is mostly fueled by Wyoming coal and nuclear power. (We now have four wind turbines in the state and last week the governor announced his support for an initiative to build many, many more).
|Newly mounted solar panels convert sunlight into electricity, sufficient for charging 24 volt electric bicycle battery. Mounting angle is approximately 45 degrees to take more advantage of summer sun.|
Charging a lead-acid battery with PV electricity makes a lot of sense. Converting normal 115 volt, 60 cycle alternating current to direct current used by the battery requires a hefty transformer and rectification circuitry, besides the necessary charge control circuits. By recharging the battery with DC current, I could eliminate the inefficiencies of converting from AC to DC, inefficiencies that you can feel when you touch any similar AC/DC converter device, of which the average American home may have dozens.
In my house, they power my Zip drive, cordless telephone, computer speakers, the portable tape recorder I use to tape EV World interviews, just to name few. There are two of them under my desk and another three next to it. If you touch them, you'll notice they are warm. That heat, modest though it might be, is wasted energy.
I didn't do anything about my solar dreams last year. Instead I enjoyed a summer and fall of riding my bike when I could, running those occasional errands my wife asked me. I would ride back to the store to get the mushrooms she forgot or to the hardware store for the 62 cents worth of lag bolts I needed. To enable me to carry that dozen eggs or gallon of skim milk, I slung a back pack over the handlebars. At my age, I probably look pretty silly peddling a bike with 16 inch wheels, but I am having fun, getting some needed exercise and creating a little less pollution running one of my cars for short trips where they spew the most emissions.
While Nebraska experienced one of its longest and coldest winters in modern memory, I stored the bike and battery in the basement and forgot about the solar charging idea. Then in late February, I got email from a colleague at work.
Ron has been experimenting with photovoltaic panels for a year, powering his backyard storage shed with them. He wrote that a local discounter had 5 watt PV panels on sale for $35 a piece, which works out to a pretty reasonable $7 a watt. He wanted to know if I'd be interested in buying a couple. If I did, he'd wire up a simple battery charger for me and build me a rack for mounting them on the side of my house. I accepted his offer and over the lunch hour, we drove over to the discounter and bought two Chinese-made panels.
I left them with Ron and later gave him my regular charger so he could test the necessary voltage and amperage levels. I'd also end up giving him the battery so he could test the charger with its intended load.
A couple weeks later, he called to tell me he had the PV panels and my new solar charger ready for me. Again over lunch hour we rendezvoused at his pickup truck and with a bright sun sparkling through scattered clouds we attached the panels to the charger and plugged in the battery. We felt like kids as the red charging light came on and the amp meter jumped to a steady 300 milliamps while the voltage meter showed a steady 26 volts in direct sunlight.
Like the year before, I had to wait for the weather to warm before I could mount my panels. My plan was to attach them below the apex of the roof on the south side of the house. It took a couple of weekends before I could get them up.
The first weekend I was able to mount the rack, but wasn't able to adjust the angle or attach the cable to the house. I wanted to watch the sun track for a day before deciding this was the location I wanted to finally mount the panels. The following day, a Sunday, I periodically checked the shadows cast by the eaves of the house. I was concerned they might shade the panels, mounted a high as they were. Satisfied, I decided to leave the rack where it was and finish the job the next day we had good weather. That wouldn't happen for another two weeks.
Then the weekend of March 31-April 1, the sun came out after a night of 50 mph winds. With winds still gusting to 25 mph, I climbed the ladder and bolted the rack to roughly 45 degrees. I also removed the black wire that my colleague had used to attach the panels to the charger, replacing it with a longer gray one that would be less obtrusive against the white side of our house.
I ran this new wire from the panels down the side of the house and into the basement through a small hole I drilled in the base plate. With the rack secure and wire secured to the side of the house with cable holders, I moved inside.
We have finished half of our basement as future office space and studio. The other half is unfinished and is lined with storage shelves. It is in this room that I mounted the charger.
I was fortunate in choosing my location because the hole in the base plate came out almost exactly above the point I wanted to install the charger.
|Solar battery charger. Gray wire supplies DC current from solar panels mounted outside. Black wire connects to battery. Left gauge shows amps, right gauge shows volts. Red light indicates battery charging.|
The charger itself consists of a plastic box that measures 7 x 5 x 3 inches, inside of which is a single circuit board. If it weren't for the analog amp and voltage meters, the entire affair could be shrunk to a quarter of its current size. The rack and charger cost me $50, the extra cable and miscellaneous parts cost another $10. The total system cost me about $130.
Counting the Costs
Now I fully realize that it is going to take a long time to repay the cost of my system when compared to the few cents it costs to charge the battery off the grid. But that's not the point. If you just look at what's the cheapest way to generatre electricity -- irrespective of its longer term environmental costs -- then grid power may be cheaper... for now.
But when you consider the longer range implications of shifting to renewable sources of energy, the simple elegance of the system, the sense of making a small, but real contribution to society and the well-being of the planet, then the cost of solar is worth every penny. Many of us Americans will think nothing of spending the cost of a PV system on a new Harley motorcycle or bass fishing boat, but when it comes to investing in solar, we seem to have a completely different mindset.
Maybe the problems in California this past winter -- and very possibly nationwide this summer -- will get us to start thinking differently about what's of value in our lives.
Anyway, enough sermonizing. Back to my tiny little PV system.
Clearly, it hasn't been in operation long enough for me to test how long it takes to recharge the battery. Since I ride my bike mostly on weekends, I figure I have all week for the panels to do the job.
Now I am thinking about looking at ways to get even more use from the panels since I think they can easily handle more than the one battery. What I am talking to Ron about now is a system that I can use to replace the five AC/DC converters that clutter the periphery of my desk here at EV World's very literal "home office."
So, I can see the next few tentative steps ahead in a journey that I would like to see end with a transportation system that is powered by sunlight and wind, two abundant, renewable and pollution-free resources. One bicycle and pair of solar panels won't change the world, but it's a start.
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