Building A Renewable Energy Powered Translator for KCAW

KCAW is a community radio station in Sitka, Alaska, a city with a population of roughly 8500.  KCAW produces its own local newscast, has volunteer programmers, and carries NPR and public radio-syndicated programming.  It has a network of seven translators which carry KCAW to seven nearby towns and hamlets:  Yakutat, Elfin Cove, Kake, Pelican, Tenakee Springs, Angoon, and Port Alexander. These towns range in population from a few dozen in Elfin Cove to about 900 in Yakutat. The population grows quite a bit every summer, when thousands converge on the region to work in the commercial fishing industry.  

Becky Meiers is KCAW’s station manager. When she took on the job five years ago, she discovered that there were many people who relied on the signal as the only radio station they could get. However, the equipment was so decrepit, there were frequent outages for weeks.  She decided to make it a top station priority to update the whole system of repeaters, and expand the reach out over the water so that the commercial fishing fleet would always be able to tune in.  

The translators were built in the 1980s, and have not been updated much since.  KCAW sends its audio feed by satellite. Satellite dishes were installed in the outlying communities in the 80s. 

Its current transmitters are mostly crystal-tuned Crown ten watt.  They are sturdy, and like much equipment of that era, were built as though they were intended to survive a nuclear war.  But they are getting pretty long in the tooth…the Crowns lack some of the features that we have come to expect in modern transmitters, such as internal audio processors, internet-based diagnostics, remote control, and monitoring through a GUI. 

Working in Port Alexander: 

Our first project was the update of the translator in Port Alexander, year-round population 56.  Port Alexander has no cars, no roads, no stores, no cell service, no grid electricity. The main sounds you hear are of the wind in the trees, the birds, and the rain-plus boats, generators, and chainsaws. I worked there for a month in August, and never used a cell phone, keys or took out my wallet.  The temperature never went above 68 while I was there.

You can only get there by seaplane, or a long boat ride.  There is frequent rain and fog, and it is not uncommon for planes to be unable to get in or out of town for 3 or 4 days. The place where we slept had electricity for just an hour in the morning, and an hour in the late afternoon.  This was enough to keep the refrigerator cold and the hot water tank full. The local foods include halibut, salmon, huckleberries, salmonberries, beach asparagus, and kelp salsa.

This summer, I hired two friends, Elizabeth Delaquess and Lu Yoder, who took vacations from their regular jobs to help out on this project. The largest business in town is the Laughing Raven Lodge, which takes guests on fishing expeditions through the summer.  

Last year, General Manager Becky Meiers and I did a preliminary project in Port Alexander. The site had been so overgrown that it was mostly impassable. The first few days was all chainsaw and machete work to establish a safe worksite. Last year’s project was to re-guy the tower. We dug three 4.5 foot holes and poured eighty bags of concrete into them, to replace the old guy anchors.  Two of the guy wires had been neglected so long that twelve inch diameter trees had grown straight through the guy wire! 

Guy wire holding up the tower– which a tree has grown completely through!

This year, once we had the tower re-secured, we were able to add twenty-one feet to it, a small wind turbine, a three-bay antenna, and a Ubiquiti to bring internet to the site.  

No Watts To Spare

We are planning an update of the entire network, with new transmitters and antennas.  But as we learned on our first visit last year, one of the biggest obstacles in these villages is electric power. 

Most of these towns have no streets; several just have boardwalks between homes that lead to the docks.  Of those that do have roads, they are just internal to the municipality.  None of the translator communities has a road that leads to any other town.  Most do not have an electrical grid. In Port Alexander, all power comes from personal generators, except for a generator that powers city hall (known as Bear Hall for the large bear skin hanging on the wall).  Transportation in and out of these towns is by boat.  Some have full landing strips for planes, others only have a seaplane harbor. 

In Port Alexander, during the course of the update,  we wanted to replace the transmitter with a new one, and go up from ten watts to our full 250 watt licensable power.  The city did not have that much power to spare, as they just have a small, underperforming battery bank, and couldn’t spare that much power for a 24-7 load and still power Bear Hall. Port Alexander gets diesel delivered once a year, by a single fuel barge.  Prices are high, generators are loud and can be unreliable, and everyone there is acutely aware of the precarity of where their energy comes from.  We realized that if we wanted to update the Port Alexander translator, there would need to be a power generation and storage aspect to the project. 

It was a happy circumstance for me, since becoming a wind and solar installer was my original career plan when I went to college in the early 90s. During the first Gulf War, I studied solar energy and appropriate technology in the hope of helping to prevent future such wars. Sadly, by the time I graduated, the Gulf War had been supposedly “won” and the solar industry was moribund for the next fifteen years. Needless to say, future oil wars were not avoided either.  I worked for a few months in solar in New Mexico, but changed careers to construction, then running a non-profit (the Prometheus Radio Project). I now run a small (one person) non-profit radio engineering outfit, the Center For International Media Action.  

I had been hoping for an opportunity to catch up on all the exciting recent developments in solar, particularly the off-grid style projects that I had studied and worked on in the 90s.  This project was a perfect match for my interests. I have been tinkering with solar around my house, and with friends, for years. This seemed like a chance to really dive in on a larger project.  

Renewing My Skills

In preparation for the Alaska project, I took on two volunteer solar projects this year to bring my skills up to date.  The first was spending a few weeks in Puerto Rico with my old friend and co-worker from New Mexico Solar work, Lu Yoder.  He worked in the New Mexico solar industry many more years than I did.  Recently, he has organized the Sol-Rincon project in Vieques.  Our crew of friends installed 5 residential systems for families who suffered for months without power during the hurricane, and continue to suffer frequent outages and outlandishly expensive electricity.   We go and volunteer to install more solar systems each winter. These systems kept electricity working for several families during the recent hurricane. www.imarad.io/vieques

The second project was installing a small system for the Philadelphia Orchard Project, which plants fruit trees on the streets of Philadelphia, where I live.   They are expanding their nursery to include two inflatable tunnel greenhouses, which need a small but constant inflation blower between the two layers of plastic.  I bought the same charge controller and batteries for the orchard, as a dry run for using the equipment in the more challenging environment of Alaska.  The installation went smoothly, and tech support from Signature Solar was excellent this spring. The one thing I did not get around to:  the inverter/charger/charge controller came with a phone app to monitor and control, but there was no internet on site at the orchard when I was working.  This came back to haunt me.  

Solar…in Alaska?

Although solar is not the first thing most people think of when they think of Alaska, there is actually a substantial resource.  In KCAW’s listening area of Southeast Coastal Alaska, the climate is less like the ice and snow people think of in Alaska, and more like a harsher version of the Pacific Northwest.  Very rainy, high winds, lots of fog, but the proximity to the ocean means that the temperature seldom stays below freezing for long. Though at first blush that doesn’t sound good for solar, the time of year that we need the most power is the summer (to reach all the fishing boats scattered around the nearby waters).  In summer, the days are quite long! While I was working there in August, first light was around 4:30a.m., and it did not get dark until 9:30p.m..  So in the same way that those vegetables grow so big further North, there can be quite a bit of sun just when you need it most.  

For solar panels, we went with a Canadian Solar panel…five panels, 400 watts each.  These panels have an interesting new feature. The cells are exposed in the back of the panel, and the manufacturer claims that in good sun you can get 10 to 40% extra power from reflected sunlight shining on the underside of them! They were around the same price as other panels, so we gave them a try.  Unfortunately, we weren’t really able to test out the product claim, given that our site has heavy vegetation on the ground.  This panel would be more appropriate when mounted on a roof painted white or silver coated.  

Our site in Port Alexander had some real challenges for solar.  It is a small site, on a ridge, but the only semi-logical place for the solar panels was in a bit of a clearing we cut from dense brush in front of the satellite dish.   It is actually about four to eight feet lower than some of the land around it.  Much of the “ground” is actually old fallen trees that have been decaying for decades. There were also so many trees nearby. We cut some, but some are rooted in the side of the ridge and were impossible to cut safely.  So, our site in the summer gets reasonable sun from around 11a.m. till 6p.m., but clearer surroundings would have definitely gotten us more hours of sun on the panels.   One thing that I observed while I was there was that even on mildly overcast days, the 2 KW array could put out 500 to 600 watts. I was encouraged that even in bad conditions, the system could provide at least enough to take care of its own overhead.  

Also, we wired all the panels in series.  Modern charge controller manufacturers have moved in the direction of accepting higher voltages, lower amperages, and panels in long strings with thinner copper wires between them.  This is all great, and has brought prices down dramatically. But the Achilles heel is when you get shading on some of the panels in the long string. Your output suffers more when you have one panel partially shaded in a series string than if you had one panel shaded, but everything else at full output in parallel. In a future visit to the site, I may choose to break up the single string of five panels into two strings of two and three, because three of the panels are relatively unshaded, while two of them are in a more problematic spot closer to the shadows of the trees. 

Wind Worries:

Wind is, in general, a trickier and more subtle resource than solar.  There are about a zillion companies that make small cheap windmills, mostly for boats.  What I have learned from reviewing the history of wind machines is that it is quite easy to make a windmill that makes electricity. What is hard is manufacturing one that can survive occasional high winds.  Since this area regularly has extremely high winds in the winter, we had to make a pretty careful selection of the windmill we would try installing. 

Things To Look For (And Avoid) When Buying A Wind Turbine

The wind industry, sadly, has a pretty bad reputation for hucksterism.  For some reason, small wind attracts the same crowd as bogus perpetual motion machines. “Energy—Free— From The Air!!!” There are a lot of small cheap wind turbines available that you can buy, but they have a tendency to blow apart in the first bad storm. There are also many “artsy” turbines that look like something out of an episode of “The Jetsons.” Unfortunately, most of these don’t produce much energy, and are more of an eco-status symbol than a practical energy technology.  

The first thing to beware of in purchasing a wind turbine is dwelling too much on the manufacturers power rating in watts.  In the US, (and on the internet), there is no standardization in how the claims of wattage output are made.  So, among small cheap turbines, there is generally a race to the bottom with companies highballing the claimed output wattage that their device makes, which has almost no relationship to its realistic output.  

There is relatively little difference between decent brands in the amount of electricity they can produce from a given swept area of turbine blades.  There is no getting around the physical theoretical maximum amount of energy that can be obtained from a given windspeed and swept area, and most reputable manufacturers have pretty similar performance. 

So a better parameter to look at than watts or exotic blade designs or whatever is actually the most straightforward: when you are shopping, the first thing to look for is the swept area of the rotor blades.  You can confirm that product claim easily enough with a ruler, when you take it out of the box!

The first approximation in planning is to look up the average wind speed per year in your area from charts provided by the National Renewable Energies Laboratory.  

Most reputable manufacturers have simple curves that show how many kilowatt hours per year you can expect to produce for their turbine, given the average windspeed at your site.  For large projects, there is no substitute for a year or two of measurements with an anemometer at the exact height and location that you intend to build.  A location may be windy, but because of local obstructions, much of the wind is turbulence, which will buffet the turbine but not produce a lot of useful electricity.  

Later in the planning process, I took similar numbers using monthly average windspeeds to approximate the kilowatt hours available month by month of both the wind and solar contributions.  

Generally speaking the best wind turbines are the simplest: two or three blades, horizontal axis.  While there have been a few vertical axis windmills that have run reliably and produced energy, there are several practical problems that have led to a long history of premature failures of vertical wind machines. 

Many inventors have been tempted by an enticing apparent advantage: with a vertical axis turbine, the weighty generator can be near the ground, so not as heavy to get up in the air, easier to service, etc.  This is true, but then you realize that you still have to get the blades far up in the air to get into unimpeded wind flow. And, you end up needing a big long heavy drive shaft to bring the power down, and the elegance of a vertical turbine starts to melt away.  Several practical issues along these lines have caused most attempts at vertical axis wind to fail…either blowing apart or not really producing more than a token quantity of power.  To learn more about wind, I recommend the books and website of Paul Gipes: wind-works.com

The Turbine We Chose

We opted for one of the most expensive in the class of very small wind turbines, from Mission Critical Energy.  They market a German-made turbine, SuperWind, in the US.  The main reason we chose them was because they had a very interesting spring-loaded furling technology. This method contracts the surface area of the blades during high winds, so as winds go up, less surface area faces them and the destructive forces are controlled. European wind is a more mature industry than we have in the US, with greater regulation and higher standards that marketed turbines have to meet. 

Since many neighborhoods have small wind turbines nearby, nothing is allowed on the market if it is found to be too noisy or to cause other troubles. Mission Critical also offered FlexSCADA, a SCADA technology interface, and an automatic cut-off switch.  We were able to install an anemometer connected to the SCADA computer. If winds reach over 70 miles an hour, FlexSCADA throws a relay which shorts the leads coming from the turbine, acting as a brake.  Also, if the Scada detects more than 7.75 amps coming from the turbine, that can also throw the relay and stop the turbine, protecting it from blowing itself apart.  

Obviously, we had no way to test this while we were working in the quiet winds of summer.  But we should be able to observe it remotely by the Scada interface and see if it is working as intended during big wind storms. 

Programming the SCADA took a significant learning curve.  SCADA uses java script in order to create commands that will implement functions such as “if amperage of sensor 6032 exceeds 7.75 amp, throw relay #4.” I admit that I got pretty worried when the company gave me a little sample code and encouraged me to “play around with it.”  I don’t know the first thing about javascript! And this code that I was going to “play around with” was going to be what stopped the windmill from ripping itself apart in gale force winds!   However, Elizabeth and I did fool around with it, and then I wrote up a detailed description of our needs, and I made a newbie attempt at writing it up in java. Then two programmers at Mission Critical looked it over, corrected it, and we tested it together over zoom…checking that amperages read correctly, wind was measured in correct units, relays would fire when voltage thresholds were crossed, etc.  I ended up being very impressed with their support for the product, I would not hesitate to buy from Mission Critical Energy again.  

Batteries, Charge Controllers, Inverters

Lithium Ion batteries are finally starting to beat lead acid batteries on the long term cost of system. They are, of course, still more expensive up front, but can be expected to last considerably longer, with deeper usable cycling and less maintenance. There are many being made now, and we still need some time to shake out reputable manufacturers from fly-by-night operations. I chose the EG4 LiFePower batteries because the price was excellent, the support was here in the US from Signature Solar…even if the batteries, like most of them these days, are manufactured in China.  Before shipping, we paid about $7000 for a 19.2 Killowatt hour system. 

One thing that has changed since the days of my work in solar has been the integration of system functions in a single box. Whereas battery chargers, charge controllers and inverters were all separate system parts when I worked in solar, I chose the EG4 as a one-box solution for all three functions.  It integrates really nicely with the rack mounted EG4 batteries.  Ethernet cables connect between the battery management systems of the batteries and the inverter/charger/charge controller. It is compact and saves a lot of trouble during installation. It is an impressive piece of equipment at a great price.  Installation could not have been easier, except for two issues. 

First: The device has a fairly high overhead in power consumption, about 65 watts of constant load all the time, even if you are only using a few watts.

(It only consumes this when it is inverting, not when it is charging or charge-controlling).   So, that is about 1.5 KWh per day you have to produce just to feed the inverter/charger/controller.  

Second: The app that comes with it was atrocious.  Despite all the connectivity of the device, there is no browser based GUI which can control it.  You can only use an app. There are two apps, and it is unclear which is better for what purpose.   Neither of them could do the main thing that they are supposed to do, which is to connect the wireless data logger and control to the local wifi network.  With the surge of interest in solar, Signature Solar tech support has been caught flat-footed.  I was surprised, because in the spring when I installed the orchard system, tech support was knowledgeable, responsive, and all around great.  But in August, I had the exact opposite experience. After a week of un-replied-to emails and webforms, I finally waited an hour on hold and got someone on the phone who had only been on the job three days, and knew far less about the system than I did. And then, his supervisor told him that Signature Solar did not support the app that comes with the EG4 inverter/charge controller/ charger. I was given an email to write to in China, which naturally never responded. So, I will not have any data on performance or remote control of certain aspects of the system until the next time that I take a seaplane out to the site.  

One lesson from this: I was very disappointed by the app and lack of support, but this is widespread in the solar industry right now.  The solar industry has many small-time operators, who are suddenly juggling more work and bigger projects than they can handle.  Some will grow to meet the challenge, and others will fall off or will narrow their specialties. There is considerable “greenflation” right now— even as devices are getting cheaper, professional-level labor and tech support is getting more expensive as demand increases.  It will take some time for the industry to catch up with its success. In addition, the supply chain issues throughout all industries mean that projects need longer purchasing and shipping lead times than we have become accustomed to. 

One fortunate thing about this project is that the town does regularly run its big generator, and the generator can’t safely run without a large load. Sometimes, they have to run big sodium vapor lights when all they want to do is power up the internet.  The town has a battery bank, but it has some serious performance issues and runs down pretty quickly, even under a small load, under 100 watts.  So, our new large radio battery bank is actually a benefit to the town of being a large sink for power that will be usable later.  We set up the FlexSCADA to throw a relay that will send 10 amps to the town battery bank whenever our bank goes above 53 volts. And we have the benefit of a bunch of extra charge from their generator to supplement the wind and solar.  The battery bank, by itself, should be able to carry us through roughly four days, even with no charge coming in from the wind, solar, or the town. The wind contribution will be small, since it is a small turbine, but significant in the fall, winter, and spring. The solar will handle most of our demand through the summer, and much in spring and fall.   Hopefully, we’ll be able to help them run their generator less often for the modest needs of town hall, and use the power they do produce more efficiently.  

Bringing Our Site To The Information Superhighway

The site had never had internet before, and was largely reliant on two devoted volunteers (including 79-year-old Budd Durdle) to climb up to the top of the ridge in the middle of the winter rain, wind, and snow, then climb back down, and call from his home landline to explain the problem, and then climb back up with a potential fix.  This probably should have been done around the time that Al Gore was vice-president, but finally, we connected this site to the internet!

We hoped to alleviate some of this by connecting the shack to the town internet at Bear Hall. We used a pair of Ubiquiti nanobeams— even though there is a lot of dense vegetation in the way, the Ubiquitis had no problem making a strong, -49 dBm connection 400 feet up the steep hill from Bear Hall to the shack.   

Like diesel and electricity, internet in Port Alexander is scarce and precarious.  Only Hughesnet provides service to regular customers there.  Hughesnet throttles dramatically after a set number of gigabytes is used each month, so internet is usually just barely acceptable for the first week or so of the month, and then gets almost unusable till the start of the next billing cycle. 

Additionally, the one public internet spot, Bear Hall (which also functions as the seat of government for Port Alexander),  had a Linksys wifi router which was bought new last year.  However, my colleague Paul Bame (engineer at the Prometheus Radio Project) was investigating the cause of the internet problems, and discovered that it had firmware from 2007.  That is when people were looking at Myspace!  The firmware actually sort of worked, but would crash and need to be rebooted every day or so, and most days the room where the router sits is locked and inaccessible.  We were able to replace it with a new router and reduce the need for router reboots, so at least the Bear Hall internet is now performing considerably better… at least as well as the Hughesnet connection will allow it.   

Paul has also developed a network architecture with a VPN where two routers can be connected to the incoming internet, and one can be used to reboot the other or take over if the other fails. Using cheap, commonly available TP-Link archer 1750, and Mango travel routers, he re-flashes them with linux routing software to be part of a VPN.   Since low-quality connections are so common at remote sites, we intend to implement this at all the sites we work on. 

An Off-Grid Approach To Antennas

The initial configuration was ten watts, with a directional antenna.  Our goal was to move up to 250 watts, omni directional, so not just the town but also the surrounding fishing grounds would be covered. I would normally put in a one or two-bay, circularly polarized antenna.  The benefit of this is that the FCC only counts the horizontal watts, so that you can put considerably more watts in the air with circular polarization.  Where electricity is cheap and effectively infinite, it is a good strategy for getting the most coverage allowable by the FCC for your license.

However, in this case, we were limited by electric power input; we did not have any electrical watts to spare.  So I opted instead for a three-bay vertical dipole from Label Italy.  This allowed me to have some gain and reduce TPO in order to get a 250 watt equivalent ERP.  The antenna install went well, with low SWR.  I had no opportunity to field test coverage (would have needed a boat) but their price was quite competitive, lead time coming from Italy was not bad, the construction was solid, and everything about it struck me as on par with American antennas at twice the price.  

The downside with a three-bay antenna is that it requires more tower space than we had.  The existing tower was Rohn 25 G,  37 feet tall, with a seven foot pointed top section. We had to replace that with a top section that could support a pole for the windmill, so we removed the top and then added three seven foot long (UPS shippable) Rohn sections plus a pole, bringing the windmill to roughly 56 feet. Using a time-lapse photo app, we captured the process of adding the sections. It makes it look easier than it is!

https://photos.google.com/share/AF1QipMofclJeJGxViZVfJSUK1tf6c8LhmelApu-psLykHQU8aKTa_ae9GUlAGZhB30Sfw/photo/AF1QipPSwwN0iR1UWORRbVpM_cTrx7jzDXO0LlxJrgxQ?key=QTFxN2p3NjhQRHNqSEhob1JkM2FjcU5XanJRajJn

Transmitter Choice

I was planning on buying a Nautel transmitter, because in such an inaccessible location, I value their ability to remote in via the internet and diagnose the failure.  However, I have learned that Ecreso has introduced internet-based diagnostic functionality as well.  I also learned that Ecreso is pioneering a new technology called SmartFM.  Essentially, it turns down the RF power when there is highly dense program material, because if it is done carefully, the listenability and coverage can remain indistinguishable. This feature is built into their new transmitters, but is not approved by the FCC for use yet, so we are looking into acquiring an experimental authorization for it. Ecreso claims that power savings can be up to 40% of what you would normally have to use, with equivalent coverage.  We look forward to trying it out.   

The Future

The Port Alexander project was the first in a series of seven projects we will do to modernize the KCAW translator system.  We were fortunate in this first project to have the interaction with the town hall generator and battery bank to make both our and their systems more efficient. We’ll do similar systems at each of the towns, so that our station can be more reliable during emergencies and be self-sufficient as well. Our projects next summer will be in somewhat larger towns: Kake and Angoon, with populations closer to 600.  I will likely take on an intern or two for summer of 2024, so please pass this article on to anyone you know with a free summer, a desire to escape the heat waves of the lower 48,  and an interest in broadcast engineering and alternative energy sources.  You can hear a story that KCAW reporter Tash Kimmell reported at this site, and see more photos of Port Alexander at:  

https://www.kcaw.org/2022/08/05/kcaw-hopes-to-bring-wind-and-solar-to-port-alexander-with-new-project/

As a side note— Port Alexander has a school for all ages: kindergarten through high school.  There are about ten total students.  They have a great residential program at the beginning of each school year, which accepts children from anywhere in the US to learn Marine Sciences for the first two months of the school year.   If you know a child who could use two months away from “civilization” with great teachers and the Alaskan wilderness as the classroom, check out the magnet program.  https://www.kcaw.org/2021/03/08/a-new-science-academy-could-keep-help-port-alexanders-school-doors-open/

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