Q&A Compiled by Glenda Hargrove and answered by the Whole Crew We try our best to directly answer all your questions. Please remember that we are limited by our own experiences. If we don't have the direct personal experience to answer your question, we will print your question anyway in hopes that a reader with the experience will answer it. So this column is not only for question by Home Power readers, but also answers. Do you have information on new battery technology? Eugene LaTenfresse, Willow, AK There are a number of developing battery technologies. Right now, nickel- cadmium cells are almost ready to be used in home power systems. The only drawback is the price which is still several times that of lead acid types. Other technologies such a rechargeable lithium cells are still some time off. Home Power will be running an article soon on the nicad types. How about an article on alternators for low power water systems? I know of someone who thinks the Ford 90 amp is the most efficient. Is this so? I have a 12V compact disc player and would like to find a 12V amp with a frequency response of 20 to 20,000 hertz, 30 to 100 watts/channel, and low distortion. Do you know of any way to get that without going to super expensive car stereos? I have an AKAI boom box that I use now. It works OK, but the fidelity isn't that great. I think an article on 12V sound would be well appreciated. Durga C. Tamm, Fort Jones, CA Well, our Hydro editor Paul Cunningham runs Energy Systems and Design, POB 1557, Sussex, New Brunswick, Canada E0E 1P0. One of his specialties is using car alternators in low head hydro situations. Write him for info and we'll get an article about this into the pipeline. I don't have any particular data on the efficiency of this Ford alternator. The efficiency of an alternator can be estimated visually by looking at two things. One, the diameter of the wire composing the stator, and Two,the overall diameter of the stator. The larger wire and the bigger overall diameter gives the alternator more efficiency. Our use of Delco and Chrysler alternators has proven to us that there is in fact great efficiency differences be different makes and models. This is a subject for an future article detailing what makes up an efficient alternator and why, complete with side by side testing of various makes and models. Right now, the hottest alternator I know of is the 100 ampere Chrysler model that look like overgrown Delcos. We're not into audio enough to answer your question about 12 VDC sound equipment. How about it, anyone out there who can answer Durga's question? It is advised, when charging a battery, to continue charging until the battery is completely full. With a PV powered system, with a motorized backup, is it customary to use the motor-gen. every day which the solar power is insufficient to provide full charge? Where can I buy a 0 to 25½ rheostat for resistive field controller for a home-built motor-gen.? Robert Weaver, Waldron Island, WA No, you don't need to run your generator every day the sun doesn't shine. Run it when the batteries are empty, or whenever you need the extra energy (like washing the clothes or vacuuming the floor). If you do start the generator, then keep it running until the batteries are full. One of the big advantages of the engine/generator is ability to completely recharge the battery. This adds years to the battery's life. You can buy a 25 Watt, 25½, Rheostat for $15.28 from Allied Electronics, 250 N.W. 39th St., Seattle WA 98107 or call 1-800-444-5700. What information do you have on PV uses in a "high grid" area? Dan Haynes, Palmer, TX Actually, none. Our personal experiences deal with "no grid" areas. We invite any PV users in areas with commercial power to contribute what they know. My wife and I felt this was a very good mag. for those striving to maintain their own power. We would like to see you include some practical working schematics and drawings. We would also like to be able to write to you with questions or problems or our own ideas. Who do we write to and will you answer? James F. Carr, Rush, KY We are happy to answer questions and print answers in this column. We will accept your articles and letters. The volume of specific questions is so great that we are unable to answer every one. We pick those that we feel have the widest interest for this column. My home power is fine. What I am interested in is future power. The first thing I would like to do is to put a Photovoltaic cell(s) to run a deep well pump, 320 feet deep. When I find out what components I need, I believe I could install it without too much trouble. I have a submersible pump now, I believe that I should go to a jack pump. This is what I need to find out. H. McManus, El Paso, TX Write Jim Allen at Solarjack Pumps, 102 West 8th St., Safford, AZ 85546 or call him at 602-428-1092. Jim specializes in PV powered jack pumps that work on very deep wells. Would like to hear more about Pelton Wheel applications. And is it possible to use steam to run power tools or numatic tools? P. Dillberg-Santosha, Kaunakakai, HI We'd like to hear from readers about Pelton wheels and the use of steam, but we ourselves have no direct experience in these matters. Are water turbines clean downstream? R.M. Olivar, Yreka, CA You bet! A properly installed and maintained water turbine should have almost no impact on a stream's environment. Would like to see information on interior lighting techniques, specifically what people are using for shading and diffusing low wattage stick fluorescents. It seems to me anything commercially available is designed for higher wattages AC. Mark Shenstone, Trumansburg, NY See the article on lighting in this issue. In a nutshell, shading and diffusing wastes light. If a light is so bright as to require shading, etc., then use a smaller light! Area lighting is for those with unlimited cheap energy. We use spot lighting. The light is where you need it and not wasted where you don't. How do you convert appliances to 12V? How about the new plethora of rechargeable appliances? They all work on 2 to 9 VDC. Bryan S. Thompson, DeKalb Junction, NY Some appliances, especially electronics like radios, and stereos, are easily converted to 12 VDC by a knowledgeable technician. Others, like appliances using motors, TVs, and VCRs, are anywhere from somewhat difficult to virtually impossible. There are too many differing appliances to be specific. Most appliances that work on DC energy at 12 Volts or less are easily converted to 12 VDC operation. We use many battery operated rechargeable appliances, drills, soldering irons, etc. and recharge their batteries off of the large 12 VDC battery system. An article about this will be forthcoming. What are specifics on rest and charge voltages for 12V systems at other than 78¡F? T. Niles,Sacramento, CA Gee, Ted, We'd like to answer this in 25 word or less, but the effects of temperature on lead acid batteries are complex. Please allow us to beg off for now and promise an article specifically about temperature and batteries in the near future. I would like to know if there is a 12V VCR that records and plays back and/or if there is a small (30 to 100 watt) inexpensive inverter suitable for powering a 120 vac VCR. Richard Wilson, Winter Harbor, ME Just about every VCR maker has a 12 VDC model for mobile/portable use. Toshiba V-X34, Panasonic Models PV-5800, PV-8500 & PV-9600, JVC models HR-S100 & HR-C3, Hitachi models VT-3P, VT-5P & VT-8P and RCA VKP 170 for example all run on 12 VDC. These units are usually more expensive than the comparable 120 vac units because fewer of them are made. Heliotrope and Trace both make excellent 500 watt inverters. Beware of the small, inexpensive, square wave type of inverters. While they do work (for a while), many VCRs and TV will experience glitches in the video due to their dirty power. A word of advise, don't waste your money on marginal inverters. Once you have an inverter, you'll find many things to plug into it. Consider 500 watts to be a minimum size. Consider only inverters with proven performance and reliability. Could you recommend an engineering firm to help me decide which source of alternative energy to pursue here in the thumb of Michigan? M.B. Haney, M.D., Almont, MI Try Chad Lampkin, Michigan Energy Works, 9605 Potters Rd., Saranac, MI 48881 or Jim Cook with Save On Solar, Inc., 6905 White Rabbit Rd., Battle Creek, MI 49017