Tag Archives: ham radio

On to Des Moines: Windpower in Adair

Teardrop Trail Log: June 14, 2017

I’ve been across Iowa many times. My friend Bob and I used to promote the Surplus Sales business at area Hamfests, and there were big annual gatherings in Cedar Rapids and Chicago. It has been 20 years or more since then and things have changed. Wind farms. Since Iowa produces corn, which was once called the fuel of the future when used to make gasohol, I assumed it was the main renewable energy industry in Iowa. Poor assumption. What a great surprise!

A little research around the Web told the story. Although Texas has the largest capacity of wind power generation in the nation (20,321 megawatts at the start of 2017), Iowa is second with a capacity of 6917 megawatts. The real surprise, it leads the nation in percentage of generation by wind — supplying over 36 % of the state’s power needs (as of 2016).

There are several reasons for this. First, Iowa is located in the wide swath of land reaching from South Texas up through North Dakota blessed with ample, year round wind. This includes other states located east of the Rocky Mountains and west of the Mississippi River. These states enjoy 50 to 100% more wind than most other states with Iowa coming in as the seventh-windiest.

Second, the Renewable Electricity Portfolio Standard, signed into law by then-governer Terry Branstad in 1983. It required utilities to purchase electricity from renewable sources at a fixed price. The state was in a farm crisis, and this was seen as a way to provide extra income to farmers who really needed it. The law was the first of its kind in the nation and was the first guaranteed market for wind energy.

On top of that, Iowa has available land, and practical farmers who saw wind “farming” as just another crop. The icing on the cake? The state attracted companies that manufacture turbine components.

When we arrived at the Iowa State Fair later that day, the first thing I noticed was the giant wind turbine on the hill next to the campsites. I never fail to learn new and inspiring things about our country as we travel in our teardrop trailer.

Wind Turbine at the Iowa State Fair

A Solar Upgrade for the Teardrop Trailer

Teardrop Trail: June 4, 2017

In the last few months, I’ve been working on a larger solar system to pump water at the ranch. We live out in the Texas Hill Country and occasionally experience power interruptions, and I wanted to use solar power to improve our emergency preparedness. The experience of designing and building that system led me to rethinking the teardrop solar system.

A New Battery

Cutting a hole for the data display

Two 100-watt solar panels provide enough power to meet our modest camping needs, but I felt the battery could be improved. We were using a marine battery, but it was a compromise between high starter current (which we would never use) and deep-cycle power for camping use. An Absorbed Glass Mat (AGM) deep-cycle seemed a better match. I ordered an Optima D34M Blue Top that could supply up to 55 Amp/hours of power and fit into the modest available space.

And a way to measure it

The new data display

Of course, fully discharging any lead-acid battery will shorten its life and normally one leaves at least a 50% charge. How do you know when you’ve reached 50% remaining power? You can estimate from the battery voltage, but measuring power directly would be best. That led to the second upgrade; a digital energy meter. It shows voltage, current and power, as well as the total power in watt/hours consumed since the last reset. Using the Optima battery as an example, I could use up to 330 watt/hours of power ((55 amp/hours / 2) * 12 volts = 330 watt hours) before it was wise to recharge.

Electric Kettles for Camping?

Finally, we enjoy electric kettles for heating water, and they’re perfect for camping. In many campgrounds, shore power is available and we can heat water for tea, coffee and washing up with ease. Would it be possible to use an electric kettle on solar power?

With 1000 watt inverter installed

Researching electric kettles and hot pots I found one model that only used about 1000 watts. A lot of power, but within reach of a not-too-expensive 12-volt to 120-volt inverter. It looked like fun to see if I could make it work, and I ordered an inverter and the necessary wiring to hook it up. Besides; the same inverter could be used to power a Crockpot or Slow-cooker — something we’ve already shown is practical.

The picture tells the story. The new battery, inverter and hot pot were connected and did indeed heat 12 ounces of water to boiling. It used 164 watt/hours of energy as measured by the new digital meter — about half of the available battery storage. Not too practical, but a fun experiment!

: Boiling water with solar energy

: Boiled water energy consumption

The Teardrop Gets a Solar Power Upgrade

Teardrop Trail Log: September 20, 2016

MC4 solar branch connectors

After the unfortunate incident with the solar panel on our way to the Red Power Roundup, we were able to use shore power for the remainder of the trip. Disappointing, but not a show stopper. We had already determined that a single 100-watt panel was not enough for our needs, so I was planning an upgrade anyway. With a trip planned in late September, it was time to act. I ordered two new 100-watt panels, MC4 combiner connectors and additional MC4 crimp-on connectors. This would double our previous power capacity and allow for daytime use of a couple of small appliances including a crock-pot and solid-state cooler.

Aluminum bar seals leading edge to teardrop

Analysis of the incident and the remaining parts of the old panel made it clear that wind entering the leading edge had repeatedly flexed the panel causing it to fatigue and ultimately fail. It seemed to me that sealing the leading edge to the teardrop roof with a rigid mount would prevent this type of failure in the future. A trip to Home Depot secured an aluminum strip, and by drilling holes that matched the existing screw mounts, I could seal the leading panel to the teardrop skin. The leading panel then overlapped the other panel so it was also sealed to the wind.

The new panels began working immediately

Once installed, the panels began producing power immediately. Although we currently only have about 80 Amp-hours of storage, the two panels can easily replace the day’s power use with 10 to 12 amp output in full sun. Also, by adding a 300-watt inverter, we are able to run a 1 1/2 quart crock pot during the day with power to spare. The next upgrade will be a larger battery.

The Ambassador was ready for a trip to Bob Sandlin State Park.

photo of solar panels on teardrop trailer

The panels overlap like shingles

You Want the Good News or the Bad News?

Teardrop Trail Log: June 15, 2016

After leaving Perry, Missouri, we settled into an afternoon of travel. After a couple of hot and humid nights in Missouri parks, populated with marauding raccoons, we decided a night in a “clean, comfortable room for the lowest price of any national chain” would be a welcome change. Marilyn had the room booked, and all was right with the world.

This was my first time on an Illinois road trip in about 30 years, and that had been on a January night in an ancient International Harvester school bus (but that’s another story), so I didn’t have a visual memory of the state. The day was sunny, and the farmland was lush. Small towns marked our progress, and we pulled into Peoria in the late afternoon. Being a larger city, I had hopes of a Mocha, and as usual, Marilyn was already on it. She turned on The Girl, and in no time, we were pulling into a Starbucks. Finally a day without incident.

All that’s left

Hot drinks in hand, I noticed something amiss on the Ambassador. Where was the solar panel? The two feed cables and wing nuts with the torn corners of the fiberglass panel were all that remained. What had happened? No idea. Disappointing, but I had already decided a single 100 watt panel wasn’t enough, so this was an opportunity for improvement. Stay tuned for the Solar Ambassador Revision 2!

Tomorrow was another day. Besides, Tom Bodett was leaving a light on for us.

There Be Dragons …

Teardrop Trail Log: June 13, 2016

I guess I should be grateful we didn’t have more problems. If you think about it, trailering is an unlikely pastime, wherein one drags a small metal box on wheels at high speed over sometimes nasty, bumpy roads and expects everything to arrive at the same time. Then there’s the summer heat, rain, and wind — all of which can be extreme. Top it off by camping in the woods with open campfires, animal encounters and rutted trails masquerading as roads, and it’s a wonder things go as smoothly as they do. It’s a testament to the essential hopefulness and naïveté of the average camper. Certainly it describes our view of staying in the woods.

Repairing the antenna tube

Looking back, I understand our first several trips were usually trouble-free. Perhaps it was payback time. After a day of construction, rain, and detours, I thought we might have taken our lumps. As it turned out, we were just getting started. Day 2 dawned cool and overcast, and wonder of wonders, there was a Starbucks nearby. We went in and ordered, and within minutes I was in possession of the magic elixir. A Mocha. On the way back to the rig, I noticed that the antenna storage tube was askew. One of the supports had broken. Better fix it.

I decided to run our solar beer cooler while we were on the road. The day promised to be sunny, and I would have cold beer while setting up camp. Off we went through Paris, Texas, on our way to Joplin. Easy travel.

Dropping voltage

Since I was curious how much power we were generating and using with the beer cooler, I checked the voltage monitor every time we stopped. The battery voltage was falling slowly, suggesting the solar panel wasn’t keeping up, but nothing to worry about. Then during one of our stops, I noticed that the battery voltage had dropped by two volts. Not normal behavior. Considering the problem while we drove the next leg of the trip, I realized that one cell in the battery had catastrophically failed. This battery was toast.

We would have to find another. Marilyn got to work with the maps. As she plotted routes and queried the web, I mused on the rotten luck. What were the odds? Batteries don’t normally fail like this. On the other hand, it was over a year old. Maybe the battery maintainer wasn’t very good. Then, she announced her result. There was a Costco in southeast Kansas City, and going there would only take us a few miles out of our way. The camping gods had smiled.

We stopped at Costco, bought a replacement battery, and installed it in the parking lot to recover the core charge. Even so, we arrived at the Jacomo Campground by 7. Plenty of light to set up while Marilyn cooked a delicious dinner. Maybe we had finally paid our karma debt and could sail unconcerned into the adventure!

A New Battery

Solar Power on the Teardrop Trail

In an earlier post, we described a simple solar system for the our teardrop. With only a 15-watt capacity, we needed to upgrade and did so last year. We’ve gotten some questions about our solar power installation on the teardrop, and I wanted to share what we’ve done. This a work in progress, but during our recent Big Bend trip, we never hooked the trailer up to shore power (aka 120 volt hookups) and used solar power almost exclusively. It’s important to state our goals however, we didn’t intend to replace shore power. Instead, we wanted to extend the practical range of our trailer, making it possible to use primitive campsites for days at a time. This is where solar power can really shine (pun intended) on a small trailer.

There are several elements to a solar system. At minimum, a solar panel, a storage battery and some kind of charge controller are needed. Additions include 120/240-volt capabilities like battery chargers and inverters. Our system is almost exclusively 12-volt. With it we run lighting and have the ability to charge multiple devices such as smart phones, tablets, a laptop and digital cameras. We even have the ability to run a few high current 12-volt appliances like an electric tea kettle intermittently. Our trailer has a 7500 BTU air conditioner (this is Texas after all), but that must be run on shore power.

photo of battery, charger and charge controller

Charge controller in place

Broadly speaking, there are two types of charge controllers: Maximum Power Point Transfer (MPPT) and Pulse Width Modulation (PWM). Both have their advantages, but a PWM controller won in cost and efficiency for our particular application: hot, sunny climates and systems of 170 watts or less. An article with a more complete comparison may help with your decision.

Here’s what we ended up with:

Renogy® 100-Watt Monocrystalline Bendable Solar Panel (update: no longer available, but this panel is similar)
Renogy® 10-Amp PWM Solar Charge Controller (update: no longer available, but this controller is similar)
Interstate Group 27 Marine Deep Cycle/Starting Battery (available from Costco)
Jensen JMP-800 75-Watt Power Inverter (plugs into a 12 volt outlet for occasional use)

Fortunately, our trailer was built with dual wiring: 12 and 120-volt. There is 120-volt power in both the galley and interior, and a 12-volt outlet is available in the interior. I added a 12-volt feed into the interior cabinets to power a Ten-Tec Triton II amateur radio. Most of the installation work involved mounting the solar panel on the trailer’s roof. The charge controller was mounted in the galley storage adjacent to the battery. The trailer was already equipped with a small charger, and it charges the battery when we’re hooked up to shore power. The solar panel can be removed from the roof and located away from the trailer using an extension cord. This way, we can park the trailer in a shady spot while the panel is located in the sun. The photos show the mounting screw installation process.

: Tapping into the aluminum skin with a double-ended screw

: Re-mounting the screw with marine epoxy

Incandescent Bulb

The trailer came with 12-volt automotive light fixtures and incandescent bulbs.

LED “corn” lamp

These were replaced with LEDs resulting in a 75% power savings. As I mentioned, it is a work in progress, and I would like to add a second panel. There’s room on the roof, and that would double our capacity.

Mounting the panel

Jim, June 7 – June 21:

I wanted to add my ham radio and a solar power system and we were about 2 weeks from departure. The TenTec Triton II radio was mounted in an interior cabinet and connected to the antenna ball mount. A piece of 3″ PVC tubing, mounted outside in the rear, provided storage for the whip antennas and their coils. A weekend shopping trip to Costco yielded a 15 watt solar panel and charge controller that I connected to the existing trailer 12 volt system. Although we were likely to have 120 volt “shore power” when camping, the solar panel could provide power if we decided to set up camp in a remote area. Time to pack!

Ranch foreman, P.T., supervises

Galley view of teardrop trailer

Door/side view of teardrop trailer

Ham radio mounted in teardrop trailer

Solar panel for teardrop trailer

Teardrop electrical system with solar charge controller

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A New Battery

And a way to measure it

Electric Kettles for Camping?

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