Tuesday, August 2, 2016

Trailer for E-trike Phase II, Solar

Phase 1 of this story which includes motivation, requirements and initial progress is located at this link:

This phase will focus on the solarization of the trailer. I will save you any suspense and show you what that looks like after many hours of testing and attaching of the solar panels.

Trailer with about 240 watts of PV panels attached.
Phase 2 began with an inventory of resources. I had designed the trailer to fit some PV panels I've obtained from a salvage operation. The three PV panels are each 35" X 38", about 22 pounds and currently output about 80 watts of power each, 240 watts total. They are old, don't look great, but being a PV expert I know they have some hidden beauty. Looks aren't everything when it comes to PV. Plus they only cost me $4 each.

I set the panels out on the grass and started testing their amperage and voltages in an attempt to figure out the safest, most cost effective way to charge the battery on the e-trike. You see, that battery is very expensive. For me, these days a DC charge controllers' goal is to make sure the battery is charged safely, cost effectively, and doesn't damage the value of the expensive battery.

Initial testing of PV panels and battery charging using a surplus charge controller
Initial testing showed that I needed another charger controller. Searched and searched, and discussed my requirements on Endless-sphere user group. A few weeks later a charge controller from China arrived, and I tested that one.

Testing of DC charge controller suitable for voltages and amps of surplus PV modules.

During this testing, the walls were off the trailer and I noticed that the size of the trike made it perfect for inside the trailer. Don't know the circumstances when I would need such knowledge, but that is one of the features of knowledge, right?
E-Trike inside the trailer.
The next task was to examine all the existing dimensions of the e-trailer, and the specifics of the PV panel, figure out all the clearances, and where the panels would be mounted so that they could grab the most sun and not be shaded, and also hinge at angles to capture the most sun. This took lots of trial and error for this prototyping activity. The wheels came off to attach the panels, or to allow for them to hinge up. The whole PV assembly is removable from the trailer with the removal of a couple brackets and studs. The wiring was put into salvaged plastic conduit, and wired to provide the appropriate voltage for the charge controller and subsequently for the battery charging.

I mounted the charge controller on a permanent wall at the front of the e-trailer.

Charge controller attached to the interior wall of e-trailer.
The positive and negative wires from the PV panels go into the charge controller, the output goes to the battery. This particular charge controller has a USB port for charging phones (only 1 amp), and an output to power appliances. It will turn the appliances off if the battery voltages go too low. I am not using that functionality, but it may prove useful in the future. Guess I should mention that this gizmo only cost $36 including shipping.

Inside of trailer has a carpet.

So now the trike can theoretically travel at 10 miles per hour using just the energy from the sun, converted by the PV panels. More likely, it will charge the battery with the panels deployed pointing directly at the sun while the trike isn't moving, charge the battery for 20 or so miles at a time. Periodically I will plug the batteries into an electrical outlet to give them a full charge and let the battery management system adjust the voltage cells of the battery pack as needed. This is called balancing the battery pack.

E-trike and solar powered trailer.
The trailer doubled in weight by adding the PV panels, originally 75 pounds, now about 144 pounds. But, the PV panels come off. I think I can still achieve my goal of a 100-pound trailer, add PV as desired. Also, PV modules are much lighter weight now than they were when these modules were produced.

The next to phases of this e-trailer build is to make a tiny kitchen front bulb out, make a back fairing with storage (similar to this blog), and make an aerodynamic space rocket that fits the top, all made out of very lightweight materials (possibly coroplast). Stay tuned, and don't hesitate to e-mail me with questions, comments or encouragement. energyideas@gmail.com Thanks for reading.

This update includes a photo from when I exhibited at the tiny house show held at the US Air Force Academy last year.

Trailer and trike at the 2016 tiny house show.

A more recent version puts two of the PV panels permanently onto the top of the trailer.

Trike being charged by PV panels, walls stowed.

48 volts and about 160 watts of power for driving the hub motor on the recumbent trike. PV panels are flat when moving.

Monday, July 11, 2016

A Whale Story

I wrote these notes a couple days ago. (photo attached)

Stayed over in Stinson Beach last night, then this morning moved to the public parking area and backed the car into a space right at the beach. Had some excellent Prius brew coffee and a crock pot stew of chipotle sauce with tuna on previously home toasted corn tortillas. Then I headed out walking north on the beach. Hadn't really explored that previously. Took some photos along the way, one of a ocean surge wall to protect the bach property next to a home with PV panels. Two different strategies for climate change. It was overcast but burning off, cool ocean breezes. 

As I was contemplating the waves, each new wave sweeping out the old and bringing in a new event, new opportunities, new reality, I noticed a paddle boarder up ahead.  Not much happening that time of the morning. Earlier I had seen some boats close to shore, couldn't tell if they were tour boats or fishing boats. There was some bird commotions too. And then I saw a whale's back. The paddle boarder was right near it, and paddling in the direct the whale was heading. Then I saw a clearer sighting, took my phone out and started shooting photos. Some really good views of the whale(s) feeding very close to shore, possibly 100 to 200 yards off shore. The feeding died down, whales gone, and the paddle boarder was moving along in the same direction as I was and then came to shore in front of where she was staying. Her camera battery had died, but I sent her some photos I had taken to her e-mail account. One very excited paddle boarder.

Continued to walk as far as I could north, 2.5 miles, then turned around. I began wondering why I didn't  go into the ocean when I saw the whales? They were so close, I could have swam with them. People travel the world and pay enormous fees for such an opportunity. How would that work? Is it too cold? Would it be safe? How far out would the whale need to be for me to go swimming? Could I strip down to my underwear, they are black and look like swim trunks?

Let me know if you want to know the rest of the story.

Saturday, June 11, 2016

Trailer for E-trike

In this blog entry, I describe the evolution of the uber-light camping trailer for the e-trike. June 11, 2016 by Joseph McCabe, PE.

I have wanted solar transportation for at least a decade. My first attempt was buying the first three wheeled car licensed for the road in Colorado. That licensing challenge was enormous, but the vehicle didn't deserve the effort. The Zapcar was not a good vehicle. I donated it to a worthy non-profit in Denver. The photo shows an actual flexible photovoltiac (PV) module charging the car. Solar electricity stored in the lead acid batteries moved that three wheeler around the neighborhood.

Photo 1: Solar Charging of EV in Colorado

Next, at considerable expense I converted my 2011 Prius to a plug-in-hybrid. This is a Gen3 Toyota Prius; the on-board computer communications haven't been hacked yet to optimize the scenario like they have on the Gen2 and Gen1. But, from a 4 kWh LiFePO4 battery pack, I can get 15 miles distance on all electric. I have been working with my local cooperative utility (that isn't very cooperative on solar yet) to try and get a community solar garden, perhaps later on this year.

Next came the electrification of the recumbent trike written about in this blog entry: http://renewableenergyspace.blogspot.com/2014/10/new-transportation-etrike-by-joseph.html 

That trike has a rear wheel drive, which I attached trailers to for towing kayaks and other things. It makes sense to have a wheel behind the seat, that pushes the driver and pulls a trailer. My thoughts wandered when thinking about camping and trailers. I like taking my trike with sporting gear to local state parks, being able to get into the park because bikes are free. We have a local park that has an archery range which I wanted to trike to with gear, and maybe do a little camping too. So the trailer design began. If you do a Google search on "Bicycle Camping Trailers" you will see YouTube videos, some of which were inspirational. I made some cardboard cut out models of possible fold out trailers. Here is a link to a video I made of that cardboard model if interested: https://goo.gl/photos/j5pndWTbipJjYs6C6  

I sketched many ideas, and made a list of some camping trailer requirements:
  • 100 lbs.
  • Rugged
  • 35" tall (this is so I can sit up in it and because I have 35" PV modules)
  • Aerodynamic, teardrop like
  • PV integrated
  • Replicate-able, can make more if others are interested
  • Small cross sectional area for limited wind loading
  • Roof mounted on cars
  • Trailer mounted
Photo 2: Some of the sketches and designs used to get project moving. Sorry, blurry.

Often I inventory things I already have to investigate building my projects. I have many long pieces of 1-1/2" angle aluminum that is 1/4" thick salvaged from an old solar installation. The PV panels I will use come from the same place. Using some of the ideas out of the sketches in photo 2 I began to work on phase 1 of the project. There are 5 phases, trailer, solar, front fairing, roof rocket and tail. 

Photo 3, 4 &5: Aluminum work.
Cut, bent and bolted the pieces as shown in the images of Photos 3, 4 and 5. Those squares are each one piece of angle aluminum. Turns out I had a box of bolts, nuts and washers that were perfect. Took a day to built to this point. 
Photo 6: Add trailer and flooring.
Another day to figure out how to do the trailer and flooring, using a trailer I had picked up at a garage sale two years earlier, and available plywood. About this time, I had worked out many design ideas, lengths and orientations. I hadn't spent any money, and the project sat for a few days because I needed to address the wall properly. I went out and paid $70 for 1-1/2" aluminum backed insulation. It isn't exactly what I wanted, what I had been designing was a better R-value system with less weight. That will have to wait, this wall material will do what is needed at this time, keep the trailer cooler in the summer and warmer in the winter.

Photo 7, Video 1 and Photo 8: Insulation walls.
You may notice the trailer is on the floor. I attached four legs that fold down to hold the trailer up, just above the wheels. The wheels can be removed, the trailer can be mounted on-top of a car, specific Yakima rack holes were placed in the frame for this purpose. I had a roll of aluminum foil backed tape that I used on all the edges of the cut insulation. At this point, with wheels the trailer weighs 75 lbs.
Photo 9, some of the hand tools used for the build.
One big challenge has been the hitch to the e-trike. I tried many scenarios which didn't work. My current solution is a light weight ball and socket that attaches the trailer to an aluminum bracket attached to the back axle of the e-trike. I attached an accordion door. The top also slides to let air and sunlight into the trailer. The walls are easily stacked inside the trailer during transportation to reduce air resistance. The trailer walls can be installed in about three minutes. 
Photo 10: E-trike attached to trailer with wheels outside trailer. 
I made a video on how I transport the trailer with the walls flat to reduce wind resistance, and how easy it is to put them into place, about 2 minutes if I knew what I was doing. Little longer for the first time like shown in this 3.5 minute video.

The trailer is so light weight that I designed it to be attached to my car rack using standard Yakima hardware.
Photo 11: Trailer mounted on-top of car with standard rack.
The next entry for this blog will be phase 2, the solar energy part. Stay tuned, and don't hesitate to e-mail me with encouragement. energyideas@gmail.com Thanks for reading.

Here is the Phase 2 blog entry: http://renewableenergyspace.blogspot.com/2016/08/trailer-for-e-trike-phase-ii-solar.html