On Kerosene RefrigeratorsÉ Thanks for the great magazine! Thanks also to those who gave me info on 12VDC color TVs & water pumps. In response to David St. John's request for info on Kerosene refrigerators and carb. kits for generators: Lehman Hardware and Appliances, Inc. has a catalog which offers two models of kerosene refrigerators and carb. kits for generators: their address is Box 41, Kidron, OH 44636, Ph: 216/857- 5441. The catalog has a wide variety of non-electric items. Garretson Equipment Co., Inc., Box 111, Mt. Pleasant, Iowa 52641, Ph: 319/385-2203 has carb. conversion kits for generators. I'm also interested in small scale production of farm methane gas. Anyone experimenting with this? Thanks again, Lisa Reynolds, Pearson, WI 54462 and againÉ In answer to David St. John's inquiry in issue #7. We have a Dometic Kerosene refrigerator we purchased from Lehman Hardware, Box 41, Kidron, OH 44636. They have been a most helpful and courteous establishment to deal with and supply a variety of products useful in a back-to-the-land life styles as they cater to a large Amish community. They also publish a catalog. Clearly it is ecologically superior to utilize solar, wind and water to satisfy one's personal power needs. This is followed in ecological acceptability by more slowly renewable resources such as wood and agricultural waste. It is less acceptable in terms of long term consequences to the planet to use fossil fuels such as kerosene but I feel we need to remain open to the wide range of possibilities. For us the use of a kerosene refrigerator and lamps enabled us to disconnect from the power grid eight years ago with virtually no complications and at an investment we could afford THEN! We have decreased our overall power consumption, learned to live lightly, bought time to really think through the sort of system we ultimately want and saved the bucks that will make it a reality. Our utilities average $110.00 per year - two 55 gallon drums of kerosene. My guess is it would have taken more fossil fuel per year to supply our needs had we remained hooked to the grid. Our system has been quite durable and utilitarian, requiring little maintenance (10 minutes 3 or so times a week). We have a freezer compartment in the refrigerator which is handy. We fill the refrigerator once a week and occasionally need to adjust the flame height when the outdoor temperature varies. Most maintenance time is spent filling the lamps. I'd be the first to admit that the use of such a system is much less than ideal because of it's dependence on fossil fuels. I'm not happy about that - at times I feel very guilty. But then few folks are "pure" - few forego cars powered by fossil fuel, sometimes recycling gets neglected, whatever. The truth is that moving to a more ecologically sound lifestyle is demanding of a family's time and energies - part of the quest is coming up with ways to make the process work. (Often it seems my critics are folks who are still "back to the land dreamers" sitting in their all electric suburban homes surrounded by old issues of "MOTHER EARTH NEWS" telling me to shape up.") It seems that our system maybe as acceptable as one that utilizes a fossil fuel generator, a system of recharging batteries with a car or whatever. As I understand energy transfer, each time energy is changed from one form to another a significant energy loss is incurred. If one employs fossil fuels it seems more efficient to use them directly for the desired purpose. And, as I said before, our system is temporary. Come spring we start our new home, planned around renewable energy sources. Ultimately it will evolve solar, wind and wood in the form of both a wood stove and a sterling engine which will supply electricity, hot water, household heating and energy for cooking at various times. So to David - do what works for you. You'll learn as you work with your system. You'll figure out what you want. If you can start with renewable energy alternatives do it. After all we're all in this because, at some level, we want to care for this beautiful planet. But if you can't do everything in an ideal way from day one that's OK too. Take it from someone who's been there and fielded criticism - it's better to start, however imperfectly, than never to venture at all. Linda Rogers, Frankfort, OH I totally agree, and apologize for suggesting that the high dollar solution of electric refrigeration is the ONLY way to go. To tell the truth, Karen and I are still using an ice box and dreaming of a Sun Frost. If there's one thing we've learned from back country living it's making do with what we have. Thanks for reminding me and sorry that you needed to do itÉ RP Jacobs Wind Machine Conversion from 32 to 24 VDC I am writing in regards to Jake Biondo's letter in "Q's & A's" in HP#7. As far as running his 32 volt Jacobs at 24 volts, he'll have no problems, provided he does not go over his rated current. The batteries will more or less "clamp" the generator output voltage at whatever the battery voltage is at. Generator voltage is dependent upon rotor RPM's, which is dependent upon wind speed. You can extract a given wattage from a given wind speed, that wattage being dependent upon the swept area of the rotor and the rotors efficiency. If the rotor diameter remains constant, you can extract more amps from a given wind if you lower the voltage. If you raise the voltage, the current will go down. Remember, watts = volts x amps. The constants in Jake's case are rotor diameter and rated current. Because the batteries are at 24 volts, the generator will obviously begin delivering current to the batteries at a lower wind speed. Conversely, the generator will peak out at a lower wind speed, again because the working voltage is lower. Jake's 2kw Jacobs is designed to produce about 50 amps maximum and generally runs in the 30 to 40 amp range. Because Jake will be running his Jacobs at only 24 volts, or about 2/3's of its rated voltage, he can only expect 2/3's of the wattage, or about 1400 watts, out of his system at its rated current. A 2kw Jacobs is designed to peak out in about a 21 mph wind. At Jake's site, which he says averages 14 to 16 mph, his Jacobs should be running at pretty near full output, current wise, most of the time if he runs it at 24 volts. Mick Sagrillo, Lake Michigan Wind & Sun, 3971 E. Bluebird Rd., Forestville, WI 54213 Propane Powered Portable Soldering Iron Re: Letter from G.L. Brown on pg. 42 of Aug/Sept issue. A better bet for soldering is a portable propane fueled iron made by Portasal, 1077 E. Edna Place, POB 1678, Covina, CA 91722. It's fueled from standard cig. lighter capsules and has a built-in light in the cap. Overall size is 20% larger than the old "Parker" fountain pen of the 30's & 40's. The figure of 90-98% efficiency (Kiszeta letter, pg 39) for inverter ballasts is hard to believe. The usual 1 transistor blocking oscillator circuits are more like 30-40%. I would certainly like to get in touch with the IOTA Company he refers to. I haven't been able to reach him for info. Sincerely, Harold May, Hinsdale, IL I'd like to second this recommendation. I've one of these propane soldering irons, given to me by Bob-O Schultze, and it works very well indeed. Inverter ballasts for fluorescents are actually reaching greater than 90% efficiency. This is not due to any radical new design, but to the wonder of the MOSFET switching transistors. The MOSFETs (Metallic Oxide Semiconductor Field Effect Transistors) waste only miniscule amounts of the energy they transfer (ON resistances are <.02˝). These jewels are also responsible for the efficiency inverters and PV controllers now on the market. RP. Using Heat to get Cool! I'm writing in response to a question from a reader, Judy McVey of Atlanta, GA. After some thought about air conditioning I realized we are trying to "dump energy". Heat is a form of energy, why not use it to help remove itself. Heat rises in a chimney-let's put a chimney around a stack of radiators or cooling coils and let the heat we are "dumping" provide the draft to keep the bottom set of coils cooled. To help induce a draft the top of the chimney could be painted black. Grass or shrubs in the area of the base of the chimney could help keep incoming air cooler. Remember a forest is 10ˇ cooler due to the shading and evaporation than an open field. INSERT DRAWING Would the looks be objectionable? Many homes have wood stoves with sheetmetal flue pipes sticking out and this has been accepted by society. My best recommendation is good ceiling insulation and a ridge vent. A ridge vent alone cut my cooling cost in half! Also keeps the insulation dry all year. Shade the south and west sides well and I've seen 12V ceiling fans. Sorry, I don't know of any gas powered air conditioners. Oh, one last idea- paint the roof white. Thanks for the great magazine. Randy Huatel The Wiz and I have been working on a home heating and cooling system driven by solar heated air. The heat portion of the system is obvious. The cooling system design uses the expansion of heated air to PULL outside air through an evaporative cooler and into the house. While all our work is still on paper, initial mathematical estimates indicate that a solar heated face can effectively cool a well insulated area to less than 20ˇF. below ambient temperature in low humidity environments. Electric Vehicles Keep up the good work. I find Home Power very informative. Does staff or any of your readers know of a source of supply for an adaptor plate for attaching an electric motor to a VW transaxle? Also appreciate any comments regarding sources for other components, such as motor, controller, etc. Ross Wagner, Erie, MI Get in touch with Michael Hackleman, his address is in his electric vehicle article in this issue. He knows sources for EV parts and conversions. RP Gas Powered Refrigeration Two questions: (1) I also am interested in converting a small gasoline generator to propane. (See letter from David St. John in issue #7) Perhaps some of your readers will have answers to that question. (2) We want to convert a natural gas Servel refrigerator to propane and would appreciate whatever information your other readers may have on this subject. The nameplate data are as follows: B11486-G, 4244765, Type C burner. Home Power is excellent, but I was disappointed in the non-answer given to St. John's very valid concern. Best wishes for Home Powers' success. 73's Nash Williams, Bonsall, CA You're not the only one who thought it was a non-answer (we did too after a few good nights sleep, sorry we messed up). Another source is Mr. James Clayton, 13417 Tutelo Rd., Apple Valley, CA 92308-6462, 800- 999-5909 wrote to say he sells conversion kits (natural gas, propane, & butane) for small engines. Send the name of the manufacturer, model number, serial number, fuel type needed, & a check for $5 for literature and a price quotation. Mr. Clayton also says that Natural Gas Sibir Refrigerators are easily converted to propane. KP Ampere-hour Metering Thanks for the great information. In the story about your place in HP#7 you mention that George Patterson helped you install a cumulative ampere-hour meter. Do you have information on where I could get or make such a meter. Perhaps for both incoming and outgoing amps. Also in your articles on equalizing batteries so voltage in the individual cells don't differ by more than .05 VDC. How do you measure the voltage of an individual cell? Thanks Much, Doug Patrick, Trapper Creek, AK First on the Ampere-hour meter: we were using an experimental lash up of some very versatile and expensive gear (all on loan I might add). This setup, while it works, contains >$2K worth of hardware. Amperage measurement is via a shunt and a 5 1/2 digit digital voltmeter (a Hewlett Packard 3468A) that talks to a Hewlett Packard 71B handheld computer. The program for the computer was written by George in Basic. This setup gave us a start on designing a dedicated Ampere-hour meter. We are currently working on a new Amp-hr. meter using the Motorola 68HC11A8 microprocessor. This single chip computer is optimized for data acquisition and process control. It contains eight channels of A/D conversion directly accessible to the microprocessor. George and the Wiz have already written the necessary code in 68HC11A8 assembly language. George is now experimenting with teaching the microprocessor to communicate with a 2 line, 32 character smart LCD display. Our eventual goal is the production of a cumulative Ampere-hour (and Watt-hour) meter that is software programmable to fit just about any system. It will be micropowered (<1 Watt) by the system it is measuring and cost less than $200. We'll be marketing this device through Home Power and will publish all technical info for those wanting to build their own. On measuring the voltage of individual lead-acid cells: this is possible if the connecting straps or wiring between the cells is accessible. For example, the Trojan L-16Ws have external connecting straps between the cells, while in the ordinary car type battery, the intercell connections are concealed beneath the case. The process is simple, IF you can get at the intercell connections. Use a good Digital VoltMeter (DVM), like the Fluke 77, with accuracy down to ±0.002 VDC. RP Inverters: Sine Wave vs. Quasi Sine Wave In your "Things That Work" article on the Heliotrope inverter, you neglected to mention whether the wave form was square, pure sinusoidal or the so-called quasi-sine. This is important to us who have quality stereo systems since square and quasi-sine inverters will frequently cause a buzz in the systems. Also, be advised that for every 12 and 24 volt system (out "there") there are probably just as many 32, 36, and 120 volt (DC) systems. Don't go neglecting us folks by over emphasizing 12 volt systems. I for one have both 12 and 32 volts available from my wind system. I keep the 12 volt bank charged directly from the 32 volt bank via a Newport Marine (Newmar) high efficiency "pulse" type 32 volt-12 volt direct converter. When I expand my system to include PV, my first low budget purchase will be to charge the 12 volt bank right off the first PV panel. As I expand with more panels I intend to augment the wind generator output with series 32 volt (feeding 32 volt battery bank) arrays, as well as more parallel 12 volt panels. Right now I produce 60% of my domestic power 9 months out of the year with a Whirlwind Power Company 4kw unit and a 3kw Heart Interface (new style, not the old Darlington unit) inverter. The rest, unfortunately comes off of Minnesota Power and Light Co.'s Coal, but that too will change when I start getting into solar. You have a really GREAT magazine here. Keep up the good work. Thanks, Tony J., Duluth, MN The Heliotrope produces what is known in the industry as a "modified sine wave". Actually this waveform is closer to a modified square wave than a modified sine wave. This is what happens when you let ad people write the copy instead of engineersÉ You are correct, the "modified sine wave" inverters will buzz out the audio and video of many types of electronics. This is not the fault of the inverter, but due to incompatibility between the inverter's power and the device under power. The manufacturer of the device intended the power supply to be sinusoidal and didn't include the additional filtration necessary for quiet operation via "modified sine wave" power. Most electronics techies can add additional capacitive filtration to the device's power supply. This, in most cases, makes the device operate quietly from an inverter. We don't mean to leave folks with DC system voltages above 12 out of our info. The fact is that most of the systems we sell and install are 12 Volts, as is our personal system. We only write about what we personally know and have experience with. If you folks with 24 VDC and higher systems want to contribute your info, then please do so. RP Disposal and/or Recycling Spent Batteries What is the proper disposal/recycling method for spent household batteries? Don Seeberger, Minneapolis, MN We'll have to ask our readers for info about proper disposal of non- rechargeable batteries. We personally have avoided this problem by moving sideways. We use rechargeable ni-cads to power up the flashlights, etc., then there isn't anything to dispose of. From my knowledge of battery chemistry, there are a number of potentially nasty materials employed in a non-rechargeable battery. These batteries use a variety of chemical technologies: zinc/carbon with an ammonium chloride & zinc chloride electrolyte (regular flashlight batteries), zinc/manganese dioxide with a potassium hydroxide electrolyte (alkaline cells), and other lithium/silver/mercury based battery technologies. Electrochemical batteries work by the intense chemical activity of their materials. As such, they represent a potential hazard to all living things. Electrolytes used in batteries are always either corrosive (chemically basic in nature), or acidic (chemically acid in nature). Electrolytes can cause acid or caustic burns. RP Sun Frost Info, Water Tanks & Paloma Demand Water Heaters Excellent magazine. I am another "off the grid" enthusiast. My system consists of four PV panels, 2 big Trojan six volt batteries in series, a Sun Frost 12 cu ft. refrigerator. As the days shorten, I have less power to spend so one thing I have done is to set the thermostat on the refrigerator down to about 65ˇF. This turns the freezer compartment into a refrigerator and the lower refrigerator section becomes only moderately cool. It is hard to control the temperature of the freezer though. The temperature monitor must be in the refrigerator section, and that is OK. I find the Sun Frost to be a good unit. But one improvement would be to have it work so that only one compartment is used when desirable without having to have two independent compressors. There has been some talk of the virtues of plastic water tanks. I am open to that. Then the precast concrete water tanks were suggested. That is better, but what I would like to suggest is the ferro-cement water tank. I have built a few of these from five to twenty thousand gallons in size. These are much bigger than the kind that a truck can deliver and be put anywhere, not just next to the road. You can build these yourself too, inexpensively. You will not want to bury these. More likely you will place the tank on the highest point of your property so you have gravity flow to anywhere. The 5000 gallon tank is a good size and it has the advantage of not needing a building permit according to the Uniform Building Codes. I have designed, built and tested a simple, easy to build 5000 gallon tank and anybody interested should write me at the address given at the end of this letter. People generally think you must have a well drilled. I collect rainwater. Totally passively a wet year will fill your tank to the brim. On a dry year maybe only half full. But that can be enough if you use it wisely. But I need help on something. I live not too far downhill from the tank so my water pressure at that point is not very high. I am about 12 feet lower than the tank water surface. If we figure about 2.4 feet of head equals 1 psi, I have about 5 psi of pressure. I am just finishing a batch type solar hot water heater, but as a backup I installed a Paloma propane fired on- demand hot water heater, only to find that it would not go on no matter what I did. The unit is supposed to work down to 4 psi according to the manufacturers, which is why I bought it. The problem is my own. Some pressure is lost in the lines. Somebody probably knows how to adjust the unit (a PSI 6) so that it will work at the low pressure or how it could be operated manually on or off as needed. Any ideas? TimoThy Traquair, POB 862, Glen Ellen, CA 95442 The Sun Frost does indeed have a single thermostatic sensor and it is located in the refrigerator section of the unit. We tested the Sun Frost RF12 in "Things that Work!" HP5, pg 33. This refrigerator/freezer can be powered by two PV panels in most locations (and most certainly anywhere in CA). Consider adding another panel or two and turning your Sun Frost's thermostat down 38ˇF. Think ice cream in JulyÉ As to the pressure problem on the water heater, how about it Paloma users? RP. Kodak Projector Unhappy on Inverter Power I have 4 ARCO M55 panels, HF-1200X2 inverter, 4@6VDC 220 amp Hour batteries, SCI charge controller. My Kodak slide projector burns out its fuse link after 1 hours operation. Runs OK on generator or power company current, for hours. The inverter has been checked. All other TV, audio (including 120vac turntable) etc., work fine. What's the problem? HELP!! I love Home Power, you are doing a great. W.E.S., Sanger, TX See Tony J's. of Duluth, MN, letter above. When Kodak designed your projector they were planning on sinusoidal power input. I'm not familiar enough with slide projectors to know what type of power supplies are built into the unit. I suspect that the power supply in the projector can be modified by a technician for inverter operation. Consult with Kodak and your local techie. Meanwhile, how about it readers?