Glück Auf is loosely translated as "good luck to us all".

Friday, December 21, 2012

Dr. Howard Resh"s PVC Pipe NFT Recipe

This web page has a wealth of information, but I was particularly interested in this part of the article.

Source: Dr. Howard Resh, Hydroponic Services

PVC Pipe NFT: An alternative to using the commercial NFT gutters is to make your own system from 2-inch (5-cm) diameter PVC pipe. Cut round holes of the correct size to fit the growing cubes you are using spaced at 7 inches (18 cm) along the pipe. Be careful when drilling the holes that they align in the same position that will be the top of the gutter. The remainder of the system is set up as described for the other NFT channels using benching and an irrigation system. An inlet header and catchment pipe circulates the solution to and from the gutters to return it to the cistern. These systems will grow uniform, high-quality lettuce.

Monday, November 26, 2012

Growing food in the desert: is this the solution to the world's food crisis?

Source: Guardian

..the work that Sundrop Farms, as they call themselves, are doing in South Australia, and just starting up in Qatar, is beyond the experimental stage. They appear to have pulled off the ultimate something-from-nothing agricultural feat – using the sun to desalinate seawater for irrigation and to heat and cool greenhouses as required, and thence cheaply grow high-quality, pesticide-free vegetables year-round in commercial quantities.

So far, the company has grown tomatoes, peppers and cucumbers by the tonne, but the same, proven technology is now almost ready to be extended to magic out, as if from thin air, unlimited quantities of many more crops – and even protein foods such as fish and chicken – but still using no fresh water and close to zero fossil fuels. Salty seawater, it hardly needs explaining, is free in every way and abundant – rather too abundant these days, as our ice caps melt away.

So well has Sundrop's 18-month project worked that investors and supermarket chains have lately been scurrying down to Port Augusta, making it hard to get a room in its few motels, or a table at the curry restaurant in the local pub. Academic agriculturalists, mainstream politicians and green activists are falling over each other to champion Sundrop. And the company's scientists, entrepreneurs and investors are about to start building an £8m, 20-acre greenhouse – 40 times bigger than the current one – which will produce 2.8m kg of tomatoes and 1.2m kg of peppers a year for supermarkets now clamouring for an exclusive contract.

It's an inspiring project, more important, it could be argued, than anything else going on in the world. Agriculture uses 60-80% of the planet's scarce fresh water, so food production that uses none at all is nothing short of miraculous.

Saturday, November 24, 2012

Our First Greenhouse

We've built our first greenhouse over the past few weeks, and I thought I would share some of the highlights of our project. Here's a time-lapse video:

Over the next few months, I intend to experiment with aquaponics and will likely post another video with more details about the results of my experiments. Some aquaponics "experts" claim that plants grow two to three times faster in an aquaponic media bed than they would in traditional soil beds. So, I'll probably grow some plants in both soil and media beds and compare the results.

Saturday, August 18, 2012

Water shortages hit US power supply - New Scientist

Here's another reason to get off the grid and find more ways to become self-sufficient. I had no idea how much water goes into energy production!

Source: New Scientist

As the United States' extended heat wave and drought threaten to raise global food prices, energy production is also feeling the pressure. Across the nation, power plants are becoming overheated and shutting down or running at lower capacity; drilling operations struggle to get the water they need, and crops that would become biofuel are withering.

While analysts say the US should survive this year without major blackouts, more frequent droughts and increased population size will continue to strain power generation in the future.

Tuesday, August 14, 2012

Design and Sizing Decisions for Solar Power Systems

I have reached a critical point in my Airstream renovation where it is necessary to make some very important design decisions for my electrical systems. I am trying to consider as many factors as reasonably possible but I have to prioritize safety, efficiency and cost.

Design Decision #1: What voltages will my system support?
Options: 12/24/48 Volts DC and 110/220 Volts AC

    Here are some estimates I have found for typical AC inverter cutoff voltage:
  • 12 volt battery, 11.5 volt minimum operation voltage, 10.5 volt cutoff;
  • 24 volt battery, 23 volt minimum operation voltage, 21 volt cutoff;
  • 12 volt battery, 46 volt minimum operation voltage, 42 volt cutoff

Lets assume that we want 100 amps at nominal voltage.

    Calculate the most optimal watts for each voltage at 100 amps:
  • 12v * 100 amp = 1,200 watts;
  • 24v * 100 amp = 2,400 watts;
  • 12v * 100 amp = 4,800 watts

AC inverters are "constant power" devices. Ohm's Law says power = voltage * current. If you run the inverter at minimum voltage it will draw more current. So the wiring fuses and all electrical components must be designed 125% of the minimums for NEC safety rating. You also have to remember that inverters are ~85% efficient.

    Calculate 125% of the Minimum Amps based upon Volt Cutoffs and Watts, at 85% efficiency:
  • 1,200 watts * 1/0.85 * 1/10.5v cutoff * 1.25 = 168 Amps minimum
  • 2,400 watts * 1/0.85 * 1/21v cutoff * 1.25 = 168 Amps minimum
  • 4,800 watts * 1/0.85 * 1/42v cutoff * 1.25 = 168 Amps minimum

Now notice the difference between Vbatt-minimum and Vcut-off of the Inverter.

    Calculate Voltage Drop:
  • 11.5 volts - 10.5 volts = 1 volt drop
  • 23 volts - 21 volts = 2 volt drop
  • 46 volts - 42 volts = 4 volt drop

    Larger DC voltage supports higher voltage drops and smaller gauge wire.
  • 48 volts can carry 4 times the power 4 times the distance as a 12 volt system using the same gauge wire.
  • Inversely, a 12 volt system requires 4 times the gauge of wire than a 48 volt system.
  • A 12 volt system carrying 240 watts would require 20 amps and a 1 volt drop.
  • A 48 volt system carrying 240 watts would require 5 amps and a 4 volt drop.
  • A 120 volt system carrying 240 watts would require 2 amps at a 3.6 volt drop.

All of these factors translate to a significant increase in cost of a 12 volt system verses a 48 volt system.

Design Decision #2: Which appliances will I use?
Options: 120VAC vs 12/24/48VDC

Most 12 volt devices are designed for cars and usually support 12 volts when the engine is off and ~14.2 volts when the engine is running. So, quite a few of these 12 volt adapters may not work well on a solar power battery bank and may get toasted during charging. A well designed AC inverter will be designed for 10.5-16 volts and output a consistent 120 VAC to appliances.

Another major factor to consider is energy conservation verses price. Some of the Energy Star rated 120 VAC appliances actually approach the efficiency of the off-grid DC appliances at a lower price and with longer life and more features. This leads me to believe that it might often make more sense to use 120 Volt AC appliances even though the inverters may cost you ~15% loss in efficiency.

Design Decision #3: What type and how many batteries will I use?
Options 12/24/48VDC

    Amp Hours(AH) vs Watt Hours (WH) vs Kilowatt Hours(kWH)
  • A 100 watt bulb running for 10 hours is 1,000 WH or 1 kWH
  • 1,000 WH / 240 VAC = 4.2 AH
  • 1,000 WH / 120 VAC = 8.3 AH
  • 1,000 WH / 48 VDC = 21 AH
  • 1,000 WH / 12 VDC = 83 AH

So, I think I have concluded that I should try to design my system for 48 VDC batteries and 120 VAC appliances.

Sunday, August 12, 2012

Thermoelectric Power Generation

It's been terribly hot in Texas these last few weeks, so I haven't been willing to work in the Airstream. So, I've been doing some research and fiddling with various power generation techniques. As I mentioned in a previous post, thermoelectric generators (TEG) seem like a very efficient way to produce a great deal of electricity from heat. However, the more I researched the use of TEG to charge batteries, the more I became discouraged about the price and complexity of thermoelectric power generation.

The manufacturer of the F2F200 TEG claims it can generate over 200 watts if the heat source is over 270° C and the cooling water flow is 1500cm3/minute at 30° C. Those are some pretty impressive specifications, but I'm having trouble imagining a practical design that could safely deliver that much heat to the TEG to maximize the power output.

The retail price for this unit is $1,919.99 and if I was to invest that kind of money I would need to be pretty sure that I can push the temperatures to the optimal 270° C. If I was to attempt to generate power with this type of TEG, I would probably build some sort of parabolic solar collector that could be easily deployed with the TEG whenever I setup camp.

Due to the extreme temperature and pressure required by this TEG, I would want to keep it far enough away from my Airstream to minimize the risk of injury in case of a leak or break in the pipes. I would also want to include some sort of a pressure release valve that would automatically safely bleed the pressure out of the system automatically and by a safety valve that can be activated from a safe distance.

I've found at least one copper pipe manufacturer (Mexflow) that discuss "maximum working pressures at temperature up to 650° C". I've also read some discussions about "brazed joints" that can withstand very high temperatures because the alloys used melt above 600°C. Unfortunately all of the brazing alloys I've found seem to recommend a maximum working temperature of about 200° C. So I might have to exceed the safety recommendations to achieve the temperature of the TEG.

I ran these ideas by some of my family who are engineers and my cousin pointed out that if the fluid is not taking the heat away from the solar collection point excessive heat can occur and would probably quickly destroy several of the components. So he suggested that I would need something that could handle the heat as a buffer.

When I started researching heat buffers, I stumbled across discussions about using 1000-2000 ton water tanks with layered heat chambers for this exact application. Now I am beginning to think that it would be difficult for a TEG to compete with PV solar at twice the cost and at least four times the complexity. I still really like the idea of using a TEG for generating electricity because I could use the TEG with a wood fired stove to generate electricity at night and then use a solar collector during the day.

As I was researching, I found a similar device called a thermoelectric (peltier) cooler (TEC). The TEC modules are mostly used in portable coolers and refrigerators and they are much cheaper then the TEG modules that are designed for power generation. The TEC modules also seem to have a much lower heat requirement for generating electricity. So, I started to wonder if a large quantity of the TEC modules could possibly be used at about 100° C instead of trying to deliver 270° C to these very expensive TEG modules.

A nice fellow named Jack posted some very detailed videos about his power generation experiment with TEC modules. Below is the last of the videos which shows the end result of his project.

I actually ordered about twenty thermoelectric cooling modules that are very similar to the ones Jack used in his experiment. I ordered the TEC modules in the hopes that I can cool and heat my Airstream and maybe even build a custom refrigerator with them. I was planning to try to generate some power with the TECs, but it seems that these modules just don't produce nearly enough energy to justify the cost of a large-scale implementation. From what I can tell, these TEC modules are designed to use minimal power for heating and cooling. So I guess I would not be using the TEC modules for the purpose they were intended and it would take a large temperature difference to create a relatively small amount of power.

So, I don't think I will attempting thermoelectric power generation until I find a more practical and cost effective TEG module.

Sunday, July 1, 2012

1966 Airstream Caravel 17' Renovation Phase III - Electrical wiring

See also:

Phase III of our Airstream renovation is all about wiring.

Over the past three months, I've spent a few hours every week pulling cables all through the inside of our Airstream. I first duct taped, some of the wires to the inside of the outer skin and then realized that all wires needed to be tightly fastened to the outer skin at least every two feet. Since I'm a geek, I installed way more cables than I think I should ever need, because this is my last chance to run cables before adding many layers of material between the outer skin and inner walls.

Approximate lengths and types of cables installed

  • 150 feet of Romex 14/3 NM-B cable - each conductor is 14 gauge and rated to 600 volts max.
  • 100 feet 16/2 Auto Zip Cord - Two stranded copper conductors rated to 300 volts max.
  • 25 feet 12/7 Trailer Wire - Seven color coded bonded stranded conductors.
  • 50 feet HDMI w/ Ethernet - Two runs for sharing video between front and back.
  • 400 feet 12/2 Speaker Wire - 7.1 Surround Sound in Front, Rear and the outside patio
  • 500 feet RG6 Quad Shield Coax - Fifteen coaxial cables for antennas and video feeds
  • 200 feet Unshielded CAT5 - Can be used for 100 mbps network, cameras, USB, etc.
  • 100 feet shielded CAT5 - Can be use for 1 gbps network conections

Planned connections at the service doors

  • Passenger Side Service Door - 7 RG6, 7 12/2 Speaker, 3 12/2 12v, 4 CAT5, 1 14/3 Romex
  • Driver Side Service Door - 1 14/3 Shore Power, 2 RG6, 1 Shielded CAT5, will add more.

This phase of the renovation probably took about 30-40 hours to complete. Yes! 30-40 hours!

Wednesday, May 16, 2012

Thermoelectric Generators and BioLite Stoves

As my Airstream renovation project continues, I have been spending a lot of time researching alternative heat, cooling and power sources that might integrate well with the Airstream bug-out shelter design requirements. A friend forwarded me a link to the BioLite Stove web site, and this got me interested enough to do a little research on Thermoelectric Generators.

BioLite CampStove Demo & Story from BioLite on Vimeo.

I've pre-ordered the BioLite CampStove and expect to receive mine sometime in July. I'll post more details after I get a chance to try it out.

I found a company called TEG Power that sells thermoelectric generators.

TEG also makes some interesting comparisons between thermoelectric generators and conventional photovoltaic (PV) solar panels.

"One 165 watt Sharp PV panel produces 0.6 kWh of electricity per day in sunny Southern California. One 25 watt TEG also produces 0.6 kWh of electricity per day (with a continuous heat source) day or night.

When you compare the costs of solar and our thermoelectric generators based on the amount of electricity they actually produce per day, you find that our TEGs cost far less per kWh than solar! The PV (photovoltaic) equivalent of 50 watts of TEG power operating on a wood stove is 330 watts of solar panels or 1.2 kWh per day. This means using just 150 watts thermoelectric power can produce the same amount of electricity in a day as 990 watts of solar PV panels. If comparing costs, the price range for 990 watts of solar would be as much as $5,000 depending on the particular brand. Whereas the cost of 150 watts of thermoelectric power can be as low as $500. Unlike solar TEGs are not dependant on the sun to producing electric power. If you have a continuous heat source, like a wood stove, TEGs can produce power day and night, 24/7-365! Granted you will need a cheap or free source of heat, but if you already have an existing heat source such as a wood stove or hot flu gases there is no added fuel cost to run the TEG! Unlike conventional electric generators powered by fossil fuels, TEGs have no moving parts to break! They are virtually silent and rated to last more than 200,000 hours of continuous operation!"

I also found the Power Pot, which is a simpler cooking pot design without the rocket stove included.

Monday, March 26, 2012

1966 Airstream Caravel 17' Renovation Phase II - Removal of interior walls

See also: 1966 Airstream Caravel 17' Renovation Phase I - Gutting the interior

As I continued the renovation of my Airstream, I removed the interior walls and the few remaining cabinets.

This phase of the renovation probably took about 6 hours to complete.

See also: 1966 Airstream Caravel 17' Renovation Phase III - Electrical wiring

Tuesday, March 20, 2012

Sea Water-Cooled Refrigeration Systems

Here's an interesting idea! There are refrigeration systems intended for marine applications that use water to cool the refrigerator. This allows you to take advantage of the typically cooler temperature of water in the ocean to reduce energy consumption. I'll bet this system could be easily adapted to be used from lakes, streams, and ground water.

The Sea Water-Cooled, ASU (Automatic Start Up*) Magnum Model 5301 Refrigeration System can cool as a refrigerator or as a freezer. The maximum freezer capacity is 3.0 Cubic Feet and the maximum refrigerator capacity is 9.2 cubic feet. This model Includes a Self-Priming Sea Water Pump that ensures extra high efficiency for tropical applications. Isotherm's ASU Models are equipped with the optional, patented Automatic Start Up System that senses when surplus power is available and stores refrigeration energy in holding plates mounted near freezer compartment. The ASU system can dramatically reduce the drain on your battery.

Isotherm Magnum Features:

  • Fridge or Freezer use
  • Included Self-Priming Sea Water Pump ensures extra high efficiency for tropical applications
  • 12/24 Volt DC Danfross Compressor
  • Easy installation with pre-charged system, "Click-on" bracket and quick connect lines
  • Variable speed water pump adjusts water volume according to the temperature of the compressor

* Isotherm ASU Systems are designed for installations in existing cool boxes and mainly for use in sailing yachts where battery power is at a premium. The ASU system dramatically reduces power consumption while supplying refrigeration in abundance. It senses when surplus power is available from the engine alternator and speeds up the compressor to rapidly freeze the holding plate. When surplus power is no longer available it reduces its energy-use accordingly. The stainless-steel holding plate can be fitted at any suitable angel high up in the box before being connected to the compressor unit by the three meter long six mm diameter flexible copper piping fitted with quick-couplings. The compressor unit is small enough to be fitted in a stowage within connecting distance from the holding plate. Extremely quiet when running, it can even be fitted under a bunk if needed. After connecting the leads to the battery, the pre-filled system is ready to go.

Isotherm ASU 5301
Max Box Volume cu.ft.
Large holding plate
Dimensions evaporator
A x B x C inches
Dimensions compressor
L x W x H inches
Power Consumption (Amp)
Average A/hour/
Max by 12 V
Weight (lbs.)
Danfoss Compressor Model
Temp Range

More Sea Water-Cooled systems can be found at

Monday, March 19, 2012

1966 Airstream Caravel 17' Renovation Phase I - Gutting the interior

I'm in the process of renovating my 1966 17' Airstream Caravel. Below is a video of the first phase of the project.

I bought this Airstream in fairly good condition, and we used it for a few camping trips before we decided to gut everything. I felt a little bit guilty destroying such a beautiful piece of history, but we decided that we would enjoy it more and get more use out of it if we completely renovated it according to our specific preferences and needs.

I drilled out all of the rivets and removed the appliances, cabinets, benches, and everything else that was inside the Airstream. Almost all of the components were put out on the curb to be picked up on bulk trash day, and I'm happy to say that all of the recyclable items were hauled away by salvagers before the city hauled the rest to the dump. I was also able to give away the original gas stove and hot water heater to somebody who will hopefully recycle it.

This phase of the renovation probably took about 10 hours to complete.

See also:

Sunday, February 12, 2012

Can you recycle 1966 Airstream 17' Caravel parts?

Over the next few weeks, we plan to gut our 1966 Airstream 17' Caravel. Since most of the parts are original and in fair condition, we would be happy to have somebody recycle them. Please let us know if you can make use of any of these parts and we'll try to arrange delivery in the DFW area or ship them to you if you aren't local. We aren't asking for you to pay for anything except the shipping costs. We just hate to see these parts be dismantled, burned or sent to a landfill if somebody can use them.

Most of the interior parts will be available, so ask if you need something you don't see. We aren't sure if we can find replacement windows, but we're pretty sure those will eventually be available too.

Contact: spam at gluck dot cc
Let us know which parts you need and we'll respond as quickly as possible.

Thursday, February 9, 2012

Airstream Minimalist Green Rennovation


Sometime between childhood and adulthood, Andreas Stravropoulos spent 4 years living in an Airstream trailer. He didn’t have a mortgage, he didn’t pay rent and he was able to pay off student loans. But it wasn’t just about gaining economic freedom.

Reconnecting Land and Architect

Stravropoulos is a landscape architect who worried about the disconnect in his profession between the architects and the land. So he moved back to the land. He parked his iconic mobile home in a backyard he was designing. From there he could watch shadows move across the land and observe how the yard’s inhabitants actually used the space.

When his adventure began Stravropoulos had been recently laid off and was launching his own landscape design business (XS Land Architects). Determined to find a mobile, modular and affordable home, he spent nights searching Craigslist until he located a 1959 Airstream travel trailer.

Once Stravropoulos had purchased his piece of history, he installed it in a friend’s sculpture studio and began its transformation. Out went the wall-to-wall linoleum and flesh tone paint. In went cork flooring, track lighting and a light paint to open up the space.

Stravropoulos did all the work himself and the trailer reflects his love of workmanship. He exposed the riveted aluminum end caps. He created custom cabinets from a birch plywood.

In this video, Stravropoulos shows us his iconic mobile home- parked (for now) behind his current home in Berkeley, California- and talks about the joy of living with just a capsule of things.

Thursday, January 26, 2012

Wood Stoves, Boilers and Ovens

As we get closer to our Airstream renovation, we have to make some important decisions about the appliances we want in and around our travel trailer. Heat is one of the most important factors for comfort and survival. So, we want to try to incorporate as many energy sources as reasonably possible. We have already installed a very compact electric heat pump and AC, but we'd like to have the option to burn wood, pellets, charcoal, gas and other fuels when electricity is not available. This post covers the most promising stoves and ovens.

The Hunter Stove Package from Cylinder Stoves

A company called Cylinder Stoves offers a unique design that includes a Stove, Warming Tray, and Water Heater. I sent an e-mail to the company explaining our Airstream rebuild project and they recommended their Hunter Stove Package which sells for $359. They also have an optional Chimney Oven for $289 that installs directly to the stove pipe. They also offer a Pellet Burner Kit for $229. That's a heck of a setup for a relatively low price, but I'm a little concerned about the size of this package and how much space it would take in our little Airstream.

Below is the only video I could find that shows the Cylinder Stoves Hunter package in action.

Kimberly Stove by Unforgettable Fire LLC

Another option we are considering is a Kimberly Wood Stove from Unforgettable Fire, LLC. This stove sells for $3500, which seems expensive, but it might be worth the investment because of it's unique patent-pending secondary combustion system which recycles exhaust gasses from the primary fire by re-burning them at temperatures of up to 1600 degrees Fahrenheit. They claim that this secondary combustion system completely incinerates all carcinogenic smoke particles before they become pollution.

In addition to logs, the Kimberly Wood Stove can burn several other fuels. In cold weather a 5lb extruded pressed log performs the best. It gives you an 8-10hr burn time with the cook top temperature exceeding 1150 degrees Fahrenheit. For Spring into Summer weather use, 1lb of standard charcoal a day will run the stove at a lower temperature range with an even cook top temperature. Pellets and gases/oils are also optional fuel choices.