Hybrid PV / Wind System Dick Linn copyright 1991 by Dick Linn The power lines didn't go past our property when I started building our house back in 1980. This was due to one of those quirks in pole routing. They were nearby, but the power company wanted the usual pound of flesh to reroute their lines to be accessible to me. So I decided to do without. I built the house and later the two story barn to store and work on motorcycles with borrowed generators and Coleman lanterns. Three or four years later the power company decided it would be in their best interest to reroute their power lines and now I have two different lines crossing our property, for which they paid me $1.00 per pole! It was too late by then though, as I had gotten stubborn and had decided to make my own power someday. So we lived with propane lights and refrigerator. Reworking a Waterpumper to Make Electricity In February of 1990, the Windmill went up. This is an old waterpumper of indeterminate origin that my neighbor, an old friend who wheels and deals for a living, found for me. I converted it to a DC generator by liberal use of old bike parts, as I had a barn full of them. I replaced the wood mainshaft bearings in the wind machine with Harley tapered roller fork neck bearings. I mounted a motorcycle rear brake drum and sprocket just behind the fan on the wind machine's mainshaft. This drives a jackshaft with two sprockets on it which in turn drive the generator. The brake also provides a means of stopping the fan when servicing. The overall gear ratio obtained was about 1:23. This speeds up the generator to where it will do some useful work. I figured on a maximum fan speed of about 100 rpm. This is using the original multibladed fan with a diameter of 8 feet. The generator itself I made using four permanent magnet Lucas bike alternators. I assembled these inside a piece of round tubing and machined end plates to house bearings and made a shaft to fit thru the assembly. These alternators originally put out approximately 10 Amps. @ 12 Volts at 3000 rpm each. They came off Triumph motorcycles from the Sixties. By wiring the output from them in series-parallel I ended up with 24 volts with a hoped for output of 20 Amps max. I used a full wave bridge to rectify the output from each of the alternator stators to get DC power to recharge to the batteries. Slip rings are necessary to carry the current from the rotating wind machine to the stationary tower. I built the slip rings up on the main vertical pipe that runs down through the main turntable bearing. This pipe pivots with the head of the wind machine. First I slipped two 1 1/2" wide pieces of black plastic water pipe over the pivot pipe. Then I slipped two pieces of copper tubing 1" wide over these. These were a snug fit over the plastic pipe pieces. I then drilled a hole through the sandwich and used insulating washers with a lip to insulate the screw from the inside pivot pipe. I ran the wire from the bridge rectifier (which is mounted on the head) down inside the pivot pipe and fastened it to the screw on the inside of the pipe. This has worked out fine. The actual brush is a piece of 3/8" copper tubing that is flattened out and rubs against the bands on the pivot pipe. The first set of brushes didn't hold up too well. They made erratic contact, so on the second set I backed them up with a piece of hack saw blade which acts as a flat spring. It's not too strong a spring but gives just enough tension to keep the copper strips in constant contact with the rings. The slip ring and brush assemblies are inside an electrical box with a hole in the top which the pivot pipe enters. The box is mounted to the lower bearing of the pivot pipe about 2 feet from the top of the tower. When I first turned it loose, the rig didn't respond to light winds. Supposedly these old mills produce power at very low wind speeds. I ran it this way for several weeks and could get about 6-7 amps at high wind speeds. I have no way to actually measure the wind's speed. I estimate wind speeds around 20-25 mph as high and around 10 mph as light. Modifications and Acts of God After the windmill had been up for about 3 weeks, we had a big storm blow one night. I clocked 17 Amps, just before the fan blew off! Never use a 2 piece mainshaft on your fan. Sooner or later it will come apart and put your fan in the trees! I pounded out the bent blades and had a friend machine a new shaft out of stainless steel. I put it back up in the wind with only two alternators. This cut down my potential output, but lowered the overall resistance to rotation. This has worked very well in light winds, giving me 6 to 7 Amps as a high, and putting out 2 Amps regularly on our breezy spring days. It won't put Jacobs out of business, but if you have a lathe and more time than money, it'll work. You could use some sort of permanent magnet motor for the generator; I just used what I had. Solar Power Enters the Picture About this time the used ARCO 16-2000 modules appeared on the market (Spring '90) so I decided that some solar panels might help cut down on the engine/generator running time. So I bought four and hooked them up temporarily in the yard. It became apparent that solar power was indeed practical in upstate New York, contrary to what all the "experts" would lead you to believe. After using the ARCOs for a month or so, I decided to spring for 8 more of them, bringing the total to 12 panels wired for 24 VDC. The panels were put on the barn roof, which is 350 ft. from the house and the batteries. One Year Later After having the system up for a year, I wanted more generating capacity. So when I saw an ad for used ARCO M52s in Home Power I called Harding Energy Systems and ordered a total of 19 more Panels without frames. Earlier I had ordered two framed panels from Photocomm. After hunting around for something suitable to frame the M52s, I found some aluminum extrusion that could do the job at a friend's trailer sales and service shop. The extrusion was originally intended to be used for mounting sliding windows in custom vans. I was able to buy this in 20 ft. lengths from him. I made the frame pieces with 45 degree cuts on each end and slid them around the panel like a picture frame. The panel fit in a groove in the extrusion embedded in silicon seal. I used flat, 2 inch, 90 degree corner braces to tie the corners together. I popriveted the brace to the extrusion. This made a fairly rigid structure. When mounted to the angle iron frames on the roof, the panels were securely supported. It cost me about $4.00 per panel to mount the panels. The angle iron frames are painted and are adjustable for inclination. I first tried to use series strings of six of these panels to charge my 24 Volt battery bank, but was only getting about 18 Watts per panel in that configuration. So I tried using seven M52s wired in series and then got about 22 Watts from each panel. This was closer to what Harding Energy Systems said I should get. After I had mounted the first two strings of panels I got a letter from Harding saying that they had been receiving complaints of low output and that if I would send copies of invoices they would send me one additional panel at no extra charge for every three I had already purchased. This seemed to back up my own findings of low output. So I sent for my four warranty panels and ordered three more so I could make one more string of seven panels. This gave me a total of three strings of seven M52 panels each. Plus the twelve ARCO 16- 2000s. So that's how I ended up with a barn roof that's more PV than tin! Battery Experiences When I first got the system on line in the Spring of '89, all we had for batteries were two Interstate 85 Amp-hr. marine batteries. They gave us a total of 85 Amp-hrs. at 24 VDC. We needed more storage capacity, but I had held off buying anything because: 1) I'm cheap and I hate to spend money, and 2) It seemed that I might get hold of some used Telco lead-acid batteries free for the taking. After eight months the Telco deal fell through, but by then I'd read enough about nickel-cadmium batteries in Home Power that I decided I had to have some. The problem was money, as usual. As it happened, a customer my company was doing a job for (we install and service industrial audio and video equipment) had a contract to refurbish New York City subway cars. Each car had a battery bank of twenty-five 140 Amp-hr. nickel-cadmium cells! At first it seemed there would be no problem taking some of the used batteries off their hands for free. However, the idea got shot down at higher management levels due to the "Big Pockets" syndrome. Apparently these batteries are considered toxic waste when they are spent. As such, the company felt it could not get free of its liability unless they paid a toxic waste handler to take them away. So that battery deal fell through also. By now I was desperate. I started checking all the places which used nicads that Richard had listed in HP#13. I started calling around and finally ran across one man who seemed sympathetic and told me to call back in a week or so and he'd see what he could find. Lo and behold I called back and he said that he had some used batteries he'd taken in that he'd sell. $5.00 for the lot. But I'd have to take them away. Needless to say, I did. They turned out to be thirty-nine 100 Amp-hr. nicad cells used for starting a diesel engine. This made a very nice 200 Amp-hr. @ 24 VDC battery bank. I had presumed that I would need 40 cells to make two 24 volt strings, but Lon Gillas at Pacific West Supply said that 19 cells per string would actually recharge better with the 31.5 Volts produced by the PVs. The 19 series cell pack should still give around 24 Volts under load. In an earlier conversation Lon had been very helpful in giving advice as to what to look for when shopping for used nicads. These turned out to be in good condition and have been working fine. Living with Nicads I cannot praise nicads highly enough. You hook them up, check the water occasionally, and that's it. These cells sat at about 1/2 to 3/4 discharge through December and January last winter and never really got a full charge until late March. The nicads never complained. If you're working around them and accidentally touch them with your clothes, no sweat: alkaline electrolyte doesn't eat your clothes! Also the tops of them don't grow all the crud and corruption that lead acid types do. I keep mine outdoors in a weather protected box and the cold Northeast winter never bothered them. My advice is don't waste your money on the Lead-Acid experience! If you can't afford to buy from the nicad recyclers advertising in HP, look around. Don't be afraid to ask people if they know where any of these critters may be living. It can't hurt to ask and you may be rewarded. One Year Later I ran the system on these batteries for one season and for sure did not have enough storage capacity. They would last me for about two to three days of no sun or wind. So I kept a look out for more nicads. I started calling around again and found another sympathetic source. The person I reached said to stop on down and talk about it. I did and he eventually showed me the pile of nicads and nickel-iron cells that he had taken out of service. I'm always surprised by the interest people show in what I'm doing. This man is very interested in PVs as a charging source, but unfortunately could not use them in his application because of remote locations inviting vandalism. Anyway, he had sixty 240 Amp-hr. nicads that were about ten years old and 89 nickel-iron (Ni-Fe) cells that were about 30 years old. About half of these Ni-Fe cells are 220 Amp-hr. capacity and the rest 100 Amp-hr.capacity. The Ni-Fe cells needed new electrolyte to restore their vigor. He told me that his company would have to pay $1.00 per pound to have the cells hauled away so he didn't feel that he could charge me anything for taking them. The nicads tested out at their rated capacity and the nickel-iron cells about half capacity. With a change of electrolyte the nickel-iron cells should get back to their original rated capacity. All this for free. He also said to keep in contact as they are continually removing these cells from service. This all adds up to about 900 Amp-hr. in nicad storage and another 250 Amp-hr. in nickel-iron. With this much capacity I have no need for a charge controller. I would like to have been more specific as to where these cells came from and give the individuals credit for their kindness, but considering the legal aspects of used batteries, I cannot. I have tried to research the legal aspects of used batteries, especially nicads. The New York State Police informed me that as long as I was hauling these cells for my own personal use the laws on hauling toxic waste did not apply. That means I can legally load them in my truck and haul them away. And it certainly isn't illegal to have them in your possession. The rub seems to be that the person that you get them from is responsible for seeing that they are hauled by a toxic waste hauler to a licensed disposal operation. So if you find someone cooperative, just remember that they are very likely putting their job on the line for you. Auxiliary Battery Charging System The sun doesn't always shine in upstate New York, and my present wind generator doesn't have the capacity to carry us through the mid- winter months. To keep the lights lit I built a gasoline powered charger much like that described in Home Power #2. In fact I started with an old Briggs & Stratton gas engine and Chevy alternator mounted on a piece of wood and used a homebuilt Mark VI charge controller to regulate. This wasn't powerful enough to suit me as the 3 1/2 hp. engine wouldn't drive the 70 Amp alternator I had. So I built another charging unit with a piece of steel channel iron for a base about 14" wide and 30" long that sits about 2" off the ground. On this I mounted a 1950 Royal Enfield 350cc single cylinder OHV motorcycle engine. This is a dry sump engine with an integral oil tank. It probably develops about 15 hp. max, but runs at less than half speed in my application. This is connected to a Ford 70 Amp alternator by V belt. The engine is also connected to a motorcycle transmission by chain so that the engine can be kick started. The engine is bolted to the base with 2" angle iron brackets. I also mounted a set of old handlebars on a couple of pieces of 1" angle iron that stick up from the base 2 ft. or so. I mounted the throttle and spark retard levers on these. They're also handy to hang onto while starting the engine. I mounted two 24 Volt muffin fans on brackets to cool the engine and these seem adequate for winter use. If I used it in the summer, it might overheat unless I mounted more fans, but it's not needed in summer. This unit will crank out 30 Amps @ 24 VDC no problem. I did nothing to the alternator to run it at 24 volts, I just used the 24 Volt version of the Mark VI to control it. Oh yes, this unit starts on first or second kick even at 5 below zero! The reason I used this engine was: 1) I already had it, it had been given to me for free, and 2) I wanted to try an OHV engine. Theoretically they are more efficient than a flathead type engine like the B&S. This seems to be borne out by my gas consumption. I don't have any hard data, but I know that it's running longer on a tank of gas than my old Briggs & Stratton unit, which I keep around for backup. We also have an old Briggs & Stratton 120 vac generator we use when I need to run the power saw or my wife Jill needs to vacuum. Wind In The Future I am gathering the components of a larger wind generator now, so that someday I won't need to use the gas powered rigs anymore! It will use a truck generator and a 60 ft. freestanding tower I've already picked up. Waterpumping There was an old hand dug well on the property when we bought it so I cleaned it out and we are using it. We pump the water to the storage tanks on the hillside above our house and let gravity flow the water down the house. To pump the water to our storage tanks, I use an old piston water pump with a Ford 12 VDC generator mounted on it as a motor. The elevation is about 25 feet. This works fine with a resistor in the feed to the field coils to drop the voltage to the fields to about 6 volts. It's hooked up to a float and sense switches so that it turns on when the level is low and off when high. I built a small logic circuit to do this. It also senses battery voltage and when voltage rises above about 29 Volts it will automatically turn on the pump and let the upper limit switch turn it back off. I won't print the schematic for this circuit yet, as once and awhile it still blows an integrated circuit! The motor draws about 8 Amps when pumping. My next project will to be to use one of these generators on my lathe as a motor. INSERT COST AND CONSUMPTION SPREADS Total usage measured on our Cruising Equipment Ampere-Hour meter: 60 to 80 Ampere-hours per day. How It Goes Together The PVs are on the barn roof on homemade angle iron mounting frames. They are wired up in four banks. Originally, there were just the two frames of ARCO 16-2000s, twelve panels total. These were wired so that you could select ,with a switch in the barn, the output from one bank of six panels, one of four panels and one of two panels. Additionally the bank of two could be switched to 12 VDC production which appeared on an outlet below the switch bank. All this switching turned out to be unneeded complexity as I only use 12 Volt option for charging. With the addition of the M52s, I modified the switching setup so that there is one bank of six 16-2000s on a switch. I then wired one bank of four 16-2000s in parallel to one frame of seven M52s, both on a second switch. This leaves one bank of two 16-2000s still switchable for 24 or 12 Volt operation on a third switch. The remaining two frames of M52s are wired to a fourth switch which I added when the new panels went up this year. All the panel outputs then go to circuit breakers before going to a main fused disconnect that leads to the house. The 12 VDC output option was added so that I could charge bike or car batteries directly from the panels. There are also Volt and Amp meters on the board. This fused disconnect feeds the underground line that runs to the house, 350 ft. away. This line is currently 2 gauge aluminum. I hope to upgrade this transmission line someday in the future. At the house there is a junction box where the line from the barn ties in to the feed to the battery box which is located behind the house, outside. I will probably move the batteries to the barn now that I have added more cells. There is a disconnect at the battery box to take them off line. The line from the battery box reenters the house and feeds the main breaker panel and the homemade 24 to 12 VDC converter. The main breaker panel is a standard 120 vac type with Square "D" breakers. The 12 Volt also goes to the main panel but only feeds one circuit now, the one for the TV and VCP. All other circuits are 24 VDC. The house was wired to NEC code as closely as possible and we use standard 120 vac switches and outlets. I just make sure that they are used at 1/4th their UL rating. As we don't have an inverter there's no problem with power mixups. When the time comes to get an inverter, I may possibly use the bright orange isolated ground outlets for 120 vac. INSERT SYSTEM DIAGRAM The Bottom Line: When I started building my "cabin" in the woods back in 1980, I had no inkling that I would someday be part of a family of four. I was content to have my escape from the world and I didn't mind if I did my reading with an Aladdin Lamp. I had it in the back of my mind that I wanted to make my own wind generator from a water pumper and felt sure that it would make all the electricity I'd ever need. Washing machines and night lights never even entered my mind! I've learned a lot these last two years and owe most of that knowledge to these pages right here. HP appeared on the scene in my life at just the right time. It's kept me from making some mistakes and led me to building a system that is fulfilling the needs of our family. I've also had a lot of fun and enjoyment building the system and I doubt if I'll ever be "finished" with it! I think it's a good experience for my boys. Only time will tell for sure, but I'm willing to bet I have the only three year old in the county that can say and knows what "electrolyte" is. And the six year old knows the difference between a nicad and a car battery! Access Dick, Jill, Ryan and Tyler Linn, RD #2, Morgan Road, Interlaken, NY 14847