An Answer to the Financing Problem In response to the inquiry about financing a Solar Electric Home. As a distributor and designer for the first FHA-HUD accepted design for a Stand-Alone Photovoltaic Passive Solar Home let me take the question Susan Mistico of Camden, NY had on financing. 1) The home you mentioned must first be shown to meet all other standard codes for dwellings and occupancies. 2) The home must have a detailed, architects approved, heating and/or cooling fraction calculation completed with a justification of the heating and cooling plant sizes. 3) The home must then have a detailed set of calculations justifying the entire home electrical system sizing for a standard home occupancy for one of its size. (i.e. a two bedroom, 1200 square foot house would at maximum have two adults and one child.) These calculations, plans and the specifications of all the equipment must be included. Any undersized wiring or connections that would not meet code will toss the system from consideration. These calculations and specifications must be approved by a professional electrical engineer and should also contain a letter from your local electrical inspector stating that if the system is installed according to code that the home will, as designed by the electrical engineer, be approved for the electrical portion. 4) The home must have an appraisal (I am a licensed real estate agent as well and found an appraiser who could make the necessary adjustments in the appraisal process). 5) The whole package, including system and product brochures and warranties, life cycle and Operations and Maintenance Costs should then be submitted to both your local FHA/HUD office for review and to your local FHA/HUD lender to find out if there are any other requirements either one may have. Approval process may take you up to a year until more submissions take place since the paperwork will be shuffled to and fro, mostly to Washington D.C. Of course, be prepared to receive the FHA/HUD acceptance and still have problems receiving a loan. These problems may come from location and the perceived marketability of your home should you default. A higher down payment may be required or additional security. A typical item that may keep you from getting the loan may be the ability to receive hazard insurance (typically fire insurance) on the home or lack of reasonable vehicular access year around. You may also not be able to qualify if you cannot make up the difference between the FHA approved loan limit for your area and the cost of your home with the system if it exceeds the FHA limit and the mortgage lender is unwilling to assume the additional risk. (Each area of the US has different FHA/HUD limits.) If this sounds like a lot to do, it is. Expect to spend 2-5% of the value of the home in getting this work done. Of course, if your financial picture is rosy the banker/lender may not require you to get FHA/HUD acceptance for insuring your mortgage. Such was the case with John Murray of Cudjoe Key, Key West, Florida, as I understand. His loan was processed thru Southeast Bank, Judy Peace was his personal banker (305) 294-4601. FMHA-Farmers Home Administration found that passive solar homes in our area had delinquent rates of 1% or less versus 11-13% for conventional homes. They have an experimental Home program for lower cost housing your readers might want to check out. Touch the Earth-Lightly, "More Power To You" Steve Verchinski, Solar Electric Systems, Inc., 2700 Espanola NE, Albuquerque, NM 87110, 505-888-1370. A Question and another Answer Congratulations on your timing: You started your publication just when I needed it. Wish I could help you in some other way than just being an avid reader. I have a tip and a query or two. The tip: Most major lending institutions know nothing about solar power and don't want to know anything. I recently wasted months trying to educate the people at Great Western. I'm surprised that the PV industry has not mounted an effective campaign in this area. I finally was able to refinance my place through Butte Savings in Chico, CA. They had already had experience with solar power and were willing to learn more about it. My advice: Ask your loan officer whether he/she is willing to lend on solar power before you fill out the applications. My query: Even when the voltmeter on my battery pack (four Trojan L-16s) reads 27 or 28 volts, the individual cells register in the red (discharge) zone of my hydrometer. How come? And if my batteries are in a discharged state (readings of 1200 on the hydrometer), why does my Trace C30 controller switch on and off (more off than on)? Why doesn't it feed the power from my six ARCO 75s into the batteries continuously until they are fully charged? If you have any PV readers in the Marysville-Oroville area I'd love to hear from them. Maybe we could have some information-trading sessions. Charles Johnson, 8038 La Porte Rd, Marysville, CA 95901 The voltage you mentioned is too low for the L-16s to be really full. Our experience with this battery shows us that a voltage of 2.50 volts per cell (under a C/20 charge rate) indicates the cell's being full. If your regulator is adjustable, then turn it up to about 30 VDC for your battery pack. Please remember that temperature as a very great effect on lead-acid cells. Cells that are below 50¡F. will have to have their voltage raised to about 2.70 (at C/20 charge rate) per cell in order to be totally refilled. Also check all wiring and connections for voltage loss in the battery/PV/regulator network. It only takes one bad, resistive connection to bring the voltage up and cause the regulator to function prematurely. Enclosed you will find my form to receive your magazine. I am considering putting in a solar system to replace my present gas-powered water pump. In addition, of course, we hope to get some fluorescent lights to raise plants in our dark springs, three reading lights at night, re-charges on our ni-cad batteries, and depending on relative cost, possibly even refrigeration. However, an important consideration would be whether a solar-driven pump could start and stop Automatically, actuated by the cast-iron weight which indicates water level in the 1,000 gal. tank near the house. As the water source is relatively thin, it would also be important that the pump deliver only a small volume per minute so as not to exceed inflow in our sandpoints. I am having some difficulty knowing how much to stress certain procedures you recommend as extending battery life. I gather some of my neighbors are not discharging down to 50% all summer long. Does one leave lights on or shut panels off to bring about the 50% discharge? Further, the 7-hour overcharge would represent a greater use of my gas- powered welder-generator than at present. Seven hours listening to it is itself costly, suggesting a spreading out of overcharge times as much as feasible. Lastly, my system would not be in use from October to March. In 6 months in constant "topped-up" state so hard on batteries that I should intentionally discharge them during that period, even though I have no use for the power? Are you able to recommend someone here locally who might make a site visit and help answer the question whether my ambitions for solar power are realistic? William B. Cook, Waldron, WA Lead-acid batteries don't require exercise. It is NOT necessary, or desirable, to cycle the batteries any lower than your consumption requires. In fact, the shallower the lead-acid battery's cycle, the longer their lifetime. PV systems left unused to long periods (over 1 month) should have regulators to prevent overcharging the batteries. Equalization charges, using your mechanical generator, may be spaced out as convenient for you. The essence of equalization is to bring all cells within the lead- acid battery pack to the same state of charge. If the individual cell voltages are within 0.05 VDC of each other, then everything is fine. If there is a cell, or cells, that differ from the others by more than 0.05 VDC, then its time to equalize until ALL cell's voltages are within the 0.05 VDC of each other. The equalizing charge is carried out at a C/20 rate (or any rate less than C/20) on an already full battery pack. It can be accomplished over several days, but be sure not to include the time it takes to bring the pack up to 100% state of charge in the equalizing charge. The seven hour time period (at C/20) is strictly ballpark, some packs require more and some less. Use the voltage differences between cells to determine when equalization is necessary and when the equalization charge is completed. At equalization rates less than C/20, the charge takes proportionally more time, i.e. at a C/40 rate it may take 14 hours to do what it took 7 hours to accomplish at the C/20 rate. So glad you are in business, Love your "Home Power". We need some information & help. We have a 1957, large size, Servel gas refrigerator. It works beautifully, but when we have high heat (over 85¡) and high humidity it defrosts in the refrigerator, the freezer works OK. We are mature adults and don't open the refrigerator very much. We also keep the refrigerator and freezer fairly full. Keep up the good work. We are interested in everything. Gloria Baublit, Almond, WI Consider the ventilation around the refrigerator/freezer. Is hot air collecting around the unit? If so, then provide the ventilation necessary for the unit to work properly. Also consider applying additional insulation (the foil backed, foam boards work well) to the sides and top of the unit. When it gets hot, refrigerators have to work much harder to keep the box cool. What were small inefficiencies in the system become big ones. So do all you can to provide your reefer with a cool place to work and to keep the heat pumped from the box from getting back in. I have PV panels and 6 -2016 AH cells - surplus telephone equipment. I would like very much to utilize the DMM method of determining the state of charge, but there are some drawbacks. First of all, in a PV, or any AE system, it is a rare day when one can allow the batteries to rest for 24 hours with no charging. Secondly, since the charge rate is not constant, there is no fixed C-rate, so the rate of charge is variable. QUESTION #1: How can I, or any AE user, determine the state of charge, under these circumstances? QUESTION #2: You stated 2 or three times in the Battery Book that the charger should be capable of C/20, but I don't think you said why. Since fast charging can damage plates, how would ultra-slow charge rates affect batteries? In my case, with the 2000 AH cells, I would have to use a 100 Amp charger. I currently have a 40 Amp charger that I use on "High", so I can obtain as much as 60 Amps, but this is still only a C/30 rate, which mostly represents the beginning charge, quickly reducing to about 50 Amps - a C/40 rate. QUESTION #3: I'm not certain if I should equalize each month, REGARDLESS of the cell voltages. My cells run within 0.02V of each other. The manufacturers label on the cells say to equalize at 2.33V for 8-24 hours, but they don't say how often. What is your advice on this? Thanks, Orin Bridges, Sandpoint, ID Question1: While under charge the voltage on a lead-acid system is elevated. Letting the pack rest for 24 hours before using the voltage measurement to determine state of charge represents an ideal situation. Letting the pack rest for as little as 2 hours can be effective, however the voltage will indicate a little high and cause the corresponding state of charge determination to also be a little high. Also not every battery has the same voltage to state of charge (SOC) relationship. The best information can be obtained by watching the voltmeter in your system; eventually you will know the relationship between voltage and SOC for your particular system. Question2: A charge rate of C/20 is ideal for equalization and is NOT a fast recharge rate for lead-acid cells. At room temperature and in the middle of their cycle (between 20% and 80% SOC), lead-acid batteries happily accept charge rates as high as C/5 without damage. There is no problem with recharge rates less than C/20, other than it takes more time to complete the recharging process or equalizing charge. In general, slower recharge rates are more efficient and give longer battery life. However, if a generator is used for recharging there are other economic considerations. The C/20 rate is a compromise between what the battery wants and the cost of running the generator for extended periods. Question3: Equalization is only necessary when there are cells within the battery whose voltage differs by more than 0.05 VDC for the other cells. If all cells' voltages measures within 0.05 VDC of each other, then everything is OK and equalization is not necessary. See the previous question in this column for more info on equalization of lead-acid cells.