Dear Home Power Crew, First of all I want to complement you for the fine magazine. The reason for this letter is to share some of my lighting experience with your readers. The THINGS THAT WORK! article in issue 4 concerns fluorescent lamps. I am not familiar with Solar Retrofit Consortium, Inc. products, but the description given is consistent with the technology. PV systems need cost effective, reliable and efficient light sources. Many of the available DC fluorescent lights leave something to be desired. Several years ago I managed a large village power project for a photovoltaic manufacturer. The systems used a total of 64, 40-watt 12- volt fixtures and were installed in schools and dispensaries in a tropic area. There were severe problems with the initial light fixtures that were manufactured by REC Specialties (now know as Thin-lite). Almost all of the inverter/ballasts burnt out during the first year of service. Those that did last a few months suffered from lamp failure after about 2,000 hours of operation. Lamps should last 15,000 hours. We reproduced the problems in the lab. The short life of the inverter ballast was due to improper operation of the power transistor (excessive base current spikes). The short lamp life was due to improper waveform (Current Crest Factor [CCF] above 2.5, more about this latter). At that time we purchased samples of all commercially available 12-volt 40-watt inverter/ballasts and complete fixtures and determined that only one manufacturer (IOTA) made an acceptable inverter/ballast. All the fixtures were replaced with fixtures using IOTA inverter/ballast and both problems disappeared. We had the same problems with 18-watt Low Pressure Sodium street lights but were unable to locate any better inverter/ballasts. Because of these problems we paid more attention to the different types of fluorescent lamps available and the ballasting requirements. There are major differences in fluorescent lamps, the OCTRONŞ series by Sylvania is far more efficient than normal lamps. The 48 inch long size fits into standard 40-watt fixtures but requires only 32 watts at 60 cycles per second (hertz) and an even lower 28 watts at 25,000 hertz and provides up to 103 initial lumens per watt (L/W). In comparison the F40SSP30/WW/RS mentioned in your article provides 91.4 L/W. Standard 40-watt fluorescent lamps provide only about 78 L/W. There are some disadvantages that must be considered; special 32 or 28-watt ballasts are required (standard 40-watt ballasts result in a very short life), higher lamp cost (about $6 wholesale), and low temperature starting difficulties. General Electric and Phillips also make equivalent lamps. I have used these lamps with a special IOTA 28-watt ballast (2D12-1-28) with good results. At present IOTA does not make higher voltage versions of this ballast. I have recently become aware of some PV powered highway signs using IOTA inverter/ballasts that have operated all night for 3 years in a hot climate with very few lamp or inverter/ballast failures. We should insist on this level of performance. Any type of light can be powered from PV, but the more efficient types are generally used. The efficiency of a lamp is expressed in terms of lumens per watt. The following table indicates the relative efficiency of the major lighting technologies: TYPE LUMENS PER WATT Incandescent 4-35 Fluorescent Standard 35-80 Miniature 50-70 High Efficiency 80-104 Mercury Vapor 57-65 High Pressure Sodium (HPS) 58-126 Multivapor 68-140 Low Pressure Sodium (LPS) 100-198 The above LUMENS PER WATT are for the lamp only; with the exception of incandescent, the lamps require ballasts to control the power. Normal ac ballasts are only 50 to 80% efficient (using normal utility power). For PV applications the ballast function is provided by an inverter/ballast with an efficiency of 90% to 98%. The higher frequencies (20-30,000 cycles per second), increase the light out of the lamp and allow economic design of the inverter/ballast due to smaller components. A few companies make good inverter/ballasts for the larger arc lamps (HPS, LPS, Multivapor, and Mercury vapor). The same concerns about inverter/ballast reliability and lamp life mentioned above for fluorescent apply to these lamps. The higher efficiency lamp technologies have several drawbacks that may eliminate them from many applications. These lamps are not suitable for flashing applications, do not render colors accurately, and with the exception of fluorescent, require warm-up times of several minutes. These drawbacks have limited their applications in PV systems. Accurate measurements of lighting performance and parameters such as CCF is very difficult. Some fixtures that appear to be very efficient because DC input power is close to the nominal lamp wattage are actually operating at lower efficiency because lamp output (lumens) is well below specification. Measurement of total lamp lumens requires very special equipment and costs about $350 per measurement. Few fixture or inverter/ballast manufacturers actually measure the output of their lamps, instead they cite the lamp manufacturers nominal rating for the lamp. Comparison of light levels produced by operating the same lamp with a standard ac ballast using utility power is the only practical method for home users to judge the relative efficiency of the available DC lighting fixtures. I hope that this information is of help to you and your readers. Very truly yours, William J. Kaszeta, President, Photovoltaic Resources International, 144 W. Meseto Ave, Mesa, AZ 85202 Dear Friends, Thank you for another informative issue of Home Power. We live about as far back in the woods as you can get in South Carolina - two miles from the nearest public road. We have no electricity in the house (yet). We have kerosene lamps for light, including two Aladdin Mantle lamps. We have a gas stove and water heater and a kerosene refrigerator (Sibir). We heat with wood. The refrigerator averages about a gallon a week and we use about $10 a month in gas for the stove and water heater. We plan to put 12VDC lights in the house (powered by PV and batteries) in the Very near future. We use a gasoline engine generator for power tools. The main thing I want to report on is our water pumping system. We get our water from a spring, pumping with a FLOJET Model 2000-732. It is powered by a pair of 6 volt, 220 amp-hour golf cart batteries. The batteries are charged by one ARCO M65 self-regulating module. This pump has to be no more than 10 feet above the source of water BUT it is pumping water 600 FEET from the spring to our house and maintaining VERY GOOD pressure (the pressure switch is set for 60 pounds). The only time we had to charge the batteries with the generator and battery charger was during November, December, and January. The only problems we've had with the pump is having to replace the pressure switch twice (if anyone purchases a system like this, it might be a good idea to order a couple of extra pressure switches - they only cost a few dollars and are very easy to replace). I would like to mention that we bought our pump and PV modules from Backwoods Solar Electric Systems. They publish their phone number in their advertisements and I have called several times with questions which were clearly explained. Their regular prices are lower than SALE prices I have seen advertised from other distributors. They will help you plan a system that will meet your needs and work in your budget. Since the initial investment is the hard part to come up with in any AE system. it helps to know that what you're getting WILL WORK. I hope this information will help the "skeptics" out there to go ahead and take the plunge. Now that I've seen PV pumping water 600 feet - I know it will light my house and I have no more second thoughts about spending the money on a system. Deborah Sullivan, Jefferson, SC Dear Richard and Karen, I just want to comment on Windy Dankoff's article in HP 5. He failed to mention the concrete tank. I've recently been researching this and here are the facts. The completely buriable poly tank sold locally is 1100 gallons and the manufacturer limits the earth fill over it to 30 inches. Where this should be plenty to keep it from freezing, it makes me wonder if it could bear the weight of, say, 4 feet of snow on top of that. The concrete tanks sold locally by the Transit Mix Company are 1400 gallons and are made in the same forms as the septic tanks. However, they add more steel and use an FDA approved form release agent. The fittings cast in the concrete are steel with a bar welded to them to keep them from rotating under tightening torque. I was told you can get a custom lid made at no extra charge but the regular one should suffice for almost any installation. There is even a 6 inch hole for a "float type" switch or valve. These units are about 10,000 pounds empty, but I can get one delivered and set in the hole for less money than the poly tank! Of course, one would need an adequate road for the delivery truck but beyond this limitation it looks like a better deal. Steve Borgatti, Hornbrook, CA Editors Note: This spring Steve, Master of the Backhoe, dug us a much needed well, which is doing GREAT! Thanks Steve. Dear Home Power, Each issue is a gem packed with information and inspiration. We recently spent $1500. on equipment from some of your advertisers: two 48 watt Kyocera panels and a Zomeworks TrackRack from Alternative Energy Engineering, a 600 watt Trace inverter from Backwoods Cabin Solar Electric, and a hydrogen-oxygen gas generator from Hydrogen Wind Inc. We are satisfied with our purchases and wish to thank Home Power for providing access. The cover photo of Mary Duffield's Aqua Alegre caught our eye. We also live on a small sailboat where we enjoy living simply and and lightly on this overburdened earth. Even in our relatively cool cloudy Pacific Northwest climate the 2 PV panels have no trouble keeping a single 12VDC marine battery charged. Direct from the battery we operate cabin lights, blender, vacuum cleaner, depth sounder, various radios, ni-cad battery charger, and a nifty heating pad that pre-warms the bed on cool nights. Marge is a seamstress and musician so the Trace inverter powers her sewing machine and a full 88-key electronic piano. During winter a wood stove does the cooking and heating, while a propane stove does the cooking in the summer. But we are hoping to replace the wood and propane with less polluting renewable home-produced fuels. So we purchased a hydrogen-oxygen generator to soak up our excess PV electricity. When the battery is charged the power is switched to the gas generator. The results are encouraging, producing bladders (air mattresses) of hydrogen and oxygen that can be ignited in a regular propane burner. The flame is truly colorless and the gases are odorless, requiring care in handling. It remains to be seen whether we can produce a useable amount of cooking fuel. We would appreciate seeing more information on hydrogen in Home Power. Keep up the good work. Enclosed is a contribution. Pacifically, Larry Warmberg & Marge Welling, Nahcotta, WA Editors Note: Thanks for the flowers and the help, both are appreciated. How about it folks, anyone out there have more info on using hydrogen- oxygen generators for to store energy? Howdy Folks; Just received my first issue of HOME POWER, Right on! I am a HAM radio operator and very involved in emergency communications, and as such, very interested in alternative energy sources, so will be looking to your magazine for information and resources. I am now using a 30 watt panel (cut in half and hinged to fold up and close for portability) to keep a deep cycle battery charged while running a Kenwood 7950 2 Meter radio during emergency and other related events. This set-up works real well except that I have to keep an eye on the attached voltmeter to keep from over charging the battery (I am in the process of building a charge controller to relieve me of this task). If any of your reader's have any knowledge in Edison batteries (older type in metal casings, EXIDE XL-4, C6E) I could sure use some help in: 1) Finding a source of small quantities of Potassium Hydroxide and Lithium Hydrate. 2) Finding the correct formula for mixing the above chemicals. 3) Finding the amp/hour ratings for the above mentioned batteries. I congratulate you on your fine magazine and hope it (and you) have a long and happy life. Sincerely, Garry Palmer N6ONZ, 333 E. Robles Ave., Santa Rosa, CA 95407- 7971 Dear Home Power, It was a pleasant surprise to find HP#4 on the "Periodicals to be Shared" shelf at our local Co-Op. We are presently only at the exploration stage of our plan to become energy independent and it was encouraging to read examples of what other people have done. Please send us HP #s 1, 2, & 3. Payment is enclosed. Keep the change. As long as I'm writing, perhaps you can answer one of our most pressing questions in our search for PV panels. Can it possibly be true that ARCO panels (the cheapest, most readily available, as far as I can tell) are produced by the Atlantic Richfield Company? The following quote from an article on the oil industry's plan to drill in the Arctic National Wildlife (Amicus Journal, Spring '88, pg.16) will explain our concerns. "With little or no monitoring, oversight, or enforcement from federal and state environmental-protection agencies, what have the oil companies that profit from Prudoe Bay done to safeguard or restore public assets? Not nearly enough, especially in light of recent corporate profits. For example, Atlantic Richfield Company (ARCO), which depends on Prudoe Bay for more than 40% of its worldwide oil production, rang up a $1.22 billion profit in 1987. Yet, even with such massive revenues, ARCO and other Prudoe Bay operators have done far too little environmental monitoring and few, if any, studies on cumulative ecological impacts. Likewise, they have given no assurances that adequate monies have been set aside for mandated habitat restoration... ARCO, for example, has attempted to refute the highly researched "Oil in the Artic" by claiming that 'selective and outdated' information was used. Yet ARCO, which obviously disagrees with the conclusions of the report, has failed to cite a single error in it..." I am hoping that you will inform me that these two ARCO's are not one and the same. However, if ARCO the PV panel manufacturer is in fact ARCO the Prudoe Bay polluter, perhaps this information should be shared with your readers. For markets to work, even alternative markets, buyers need as much information as possible. Maybe one of your market-wise associates could address the environmental sensitivities of PV panel producers in a future edition of HP. Thanks for putting us on your mailing list. Keep up the good work. Sincerely, Tom Bik & Family, Carbondale, IL Editors Note: Yep, Arco Solar is mostly owned by Atlantic Richfield Company. Of course if you go back far enough most, but not all, solar manufacturers are controlled by oil companies (or so we've been told). Dear Home Power, We've been receiving your magazine since the first issue and have looked forward to receiving each succeeding issue. You are really doing a fine job letting people know about the different aspects of Alternative energy. Articles such as the one about "Mary Duffield" teaching a small handful of young people about Alternative ideas is truly an inspiration to all of us who are concerned about the earth. We all really can make a difference!The article by "Steve Willey" about wind generators, indirectly gave me insight to who "Backwoods Solar Electric" is. It's a good way to learn about suppliers of equipment and knowledge that you may eventually be in contact with. The editorial "What's Home" I think "hits home" for everyone who has AE systems working. By living with AE we're all doing what we can to make the world a better place to live. Writing to government officials about alternative ways to produce electricity and being aware of the books in school systems that promote nuclear power and mentions nothing of Alternative energies as Ronald Solberg point out (in letters), are great ways to promote what we believe in. Also, being a supporter of environmental groups, I recently received a letter from the "Natural Resource Defense Council" (NRDC) who are filing suit against "ARCO Alaska Inc." for polluting and causing environmental damage in Northern Alaska. I assume this is a subsidiary of the ARCO who make Photovoltaic systems, etc. It seems that they have one foot in each door! Therefore by not purchasing their products we may be able to have an effect on their actions. Some response to this would be most helpful to me! Our own AE system is very simple. Two 35 watt "Hoxan" photovoltaic panels producing approx. 20 amp hrs. daily to two 12 volt deep cycle batteries with a total capacity of 240 amp hrs. One Heart-1200-X inverter, a Marquette 80 amp battery charger and a 2900 watt Kowasaki generator for back-up and workshop. The system works extremely well because we limit our use to what we can produce, therefore only needing to charge the batteries with the generator every 2 months. I based my system on "Jim Cullens" book "How to be your own Power Company" 8 years ago! MY how things changed! But thanks to him I've been heading up the right path. Thank you Jim, wherever you might be? We use propane for refrigeration and cooking (wood cookstove in winter). The Swiss-made "Sibir" refrigerator is an exceptional product. Temperature control is set on minimum of 1 no matter what the weather. 3 years in use and no problems. Enclosed are 3 more subscriptions to your wonderful magazine. Only 1 of the people are now using AE, but the others are very interested. If you could, would you please send back issues #4 & 5 of "Home Power" to these 3 individuals. Enclosed also is a check for $40.00 covering the back issues as well as helping to keep this very important information that you produce flowing! Keep up the excellent work! Sincerely, Bill Sams, Scottsville, VA Dear HP, I just got back from a trip through Central America & was much impressed by the potential for alternative energy of all forms, especially PVs. Many areas have no access to the power grid & seem to offer a chance for development along community & personal lines rather than giant resource- guzzling plants. Is anybody else interested in this? I would be interested in other peoples thoughts. Thanks for publishing this, don't do it for free, though, you'll burn out for sure! Thanks Again, Jerome Baker, 5410N 225W, West Lafayette, IN 47906 Editors Note: Well, the candle has been burning at both ends but it's a long way from burning out! Hello Folks, Thank you for my subscription to Home Power. It's a most informative and interesting magazine. I have been happily using water power for six years as my primary power source. (Tnx to Steve Willey) Yesterday I constructed the "Pulsar" nicad battery charger, (Home Power 5), and it appears to be a real winner. In Home Power #4 I noted that Fred Richardson of Waldron, WA was looking for a high powered 12 volt soldering iron. I see Dick Smith Electronics, PO Box 468, Greenwood, IN 46142 (tel. 317-887-3425), has what looks like a good one for $29.95. It is 12 volts, 30 to 150 watts - their cat. # T-1650. It features a carbon element and the wattage is said to be adjustable as you solder and to heat up in just 3 seconds. The brand name is Superscope. My subscription started with Home Power #4, so enclosed please find my check and send issues number 1, 2, 3. Thanks again for a fine magazine and Keep them coming. Sincerely Yours, Gerald L. Brown, Porthill, ID Glad to see your theory articles. As an engineer, I am amazed to see how few people understand their light switches in our totally electric society. It is my experience that 100% of the people I have seen using gas generators GIVE UP and connect to their public utility. Donald F. Scott, Goldendale, WA Howdy, I enjoy; letters to Home Power. Home Power is a useful way to educate the consumer (me). It must be challenging sometimes. But someones got to do it. Uncle Sam would if he could but he can't so he won't. Sometimes I'm ashamed to be related to him. But he may see the LIGHTbulb and have a change of heart soon. Let us pray he does. Thanks, J. J., Western, NC Home Power, Another letter to tell you that Home Power is very informative with lots of valuable information. I really believe that AE has a future in the US if the energy tax credits are brought back. Everyone should write their legislators urging them to support alternative energy and federal tax credits. Dave Maugans, Cherryvale, KS