Big Uns & Lil Uns Richard Perez One of the greatest advantages to using sunshine to make electricity is freedom-- freedom to live where we want and how we want. All we have to do is lightly tap Mama Nature for a smidgen of her endless energy. Our system's size depends on us, on our needs and desires. If you don't need the power, then you don't have to either produce it or pay for it. Here's an article about a large system that meets large needs and a smaller one that meets smaller needs. Both work and are cost- effective. Both point out the freedom and flexibility built into photovoltaic systems. Lil Uns When Bill and Jean Andrews moved to their mountain home in June of this year, they were ready to leave many conveniences behind. Well, Bill was and Jean remained to be convincedÉ Bill, a retired logger, and Jean love the peaceful beauty of the high country. At 4,500 feet in the Siskiyou Mountains of southwestern Oregon, their home has a panoramic view of snow-covered Mt. Shasta some 60 miles away. Bill & Jean's home is on a south facing slope surrounded by tall douglas fir and ponderosa pine trees. There's a spring that flows into a small pond in their front yard, home to a least a million frogs and tadpoles. Their 80 year old log cabin is located about 2.5 airline miles from commercial electricity. The nearest paved highway is over five long, rough, muddy, and deeply rutted miles away. Electrical alternatives, other than running in the commercial grid at $70,600, included an engine/generator and photovoltaics (PVs). They choose to use a stand alone PV system for essential electrical chores like communication and lighting. Bill & Jean's Electrical Consumption Every system starts with a thorough survey of the appliances, Bill & Jean's was no exception. They sought help from Electron Connection in specifying and installing their system. In Bill & Jean's case the list of appliances was very short. They only need electricity for two functions, communications and lighting. The chart below details the appliances and their consumption. INSERTCHART We decided right off to put all the electrical appliances on 12 VDC and not to use an inverter in this system. With such small scale consumption, PVs are easily capable of producing all the energy without the necessity of a back-up engine/generator. Twelve Volt lighting is readily available in either fluorescent or incandescent models. Just about all 2-way radios, either CB or radiotelephone, are available in 12 VDC powered models. Electrical power consumption averages about 500 Watt-hours daily. INSERT INTERIOR PHOTO Bill & Jean's PV System This system has only two major components, PV panels and batteries. The PVs produce the power and the batteries store it. Very simple and very direct and very inexpensive. The two Trojan L-16Ws form a battery that will store about 6 sunless days of power for Bill and Jean. Each Kyocera 48 Watt PV panel will produce about 250 Watt- hours per sunny day in this location. There is NO generator in this system, PVs are the ONLY power input. The cost of this system is detailed in the spreadsheet and chart below. Please note that the low cost of this system is due to Bill & Jean's very small electrical consumption. Once again, if you don't consume the energy, then you don't have to generate it, store it or convert it. Stand alone PV system cost is directly proportional to the amount of power required from the system. Note also that Bill & Jean had us install a rack for four PV panels eventhough they now only use two panels. In stand- alone PV systems this is a very good idea. As the system's electrical consumption grows (and it always seems to), then adding more panels is simple and direct. INSERTSPREADANDCHART Big Uns Jim and Laura Flett moved to the Siskiyou Mountains in 1980. This is the very same mountain range that Bill & Jean inhabit, but far enough south to be in California rather than Oregon. Jim is a farrier and Laura is a physical therapist, both run their own businesses out of their backwoods home. Their 80 acre homestead along Camp Creek is home to Jim, Laura, their two children Saylor and Dana, two horses- Shorty and JosŽ, and numerous other critters. Jim and Laura moved to the hills for the same reasons that most of us have- freedom, a clean unspoiled environment, and some basic peace & quiet. Jim & Laura's home is located about 2 miles from the nearest commercial electricity. At today's rates, the power company wants about $60,000 to run in the lines. It's easy to see why Jim & Laura decided to make their own power. Jim & Laura's Power Consumption Jim and Laura's home is a large ranch house equipped with the conveniences needed for effective country living. They consume electricity both as 120 vac from their inverter and as 12 VDC directly from the batteries. The chart below details the major consumers of inverter produced 120 vac power. INSERT120VACCHART The 12 VDC appliances are powered directly from the batteries and are detailed in the chart below. INSERT12VDCCHART Total power consumption adds up to about 2,000 Watt-hours per day, including inverter inefficiency and several small intermittently used appliances not listed in the charts. When Jim and Laura first moved to the mountains, their electrical system was much smaller and sourced by a single engine generator. During the eight years before they invested in PVs, an inverter and a much larger battery pack, they learned well the lessons of conservation. Even now, they religiously perform the small tasks that make their system so efficient and effective. Tasks like, turning off lights that are not in use, using efficient lighting and placing it where illumination is needed. While Jim & Laura use their system like veteran energy misers, the visitors to their home are unaware that it's not plugged into the grid. Some visitors leave the house without ever knowing that the electricity they used there was solar produced and battery stored. Jim & Laura' house is interesting from an electrical standpoint because the home is totally wired for both 12 VDC and 120 vac. Everywhere there is a 120 vac wall receptacle (and there are lots of them because the house is wired to NEC code), there is a 12 VDC outlet. Everywhere there is a permanently mounted 120 vac light, there is also a permanently mounted 12 VDC light. The 12 VDC wiring system was done as follows. Two 0 gauge copper cables feed DC energy from the battery to a buss in the attic. This buss is made from #2 copper wire and runs about 65 feet along the attic crawl space of this single story ranch type house. Each 12 VDC outlet or light is individually connected to the buss (no daisy-chaining like 120 vac circuits). All connections to the buss are soldered! INSERT INTERIOR PHOTO LAYOUT Jim & Laura's PV/Engine System First off, this system is very different from Bill and Jean's because it didn't happen all at once or as an integrated unit. It grew gradually over the years with their needs and as the equipment became affordable. As such, Jim & Laura's system contains items like redundant generators that are only very occasionally used now. The main power source is eight 48 Watt Kyocera PV modules. This photovoltaic array produces about 23 Amperes in full sun, or about 2,000 Watt-hours daily. The PV produced electricity is passed through a Heliotrope CC-60 PWM charge controller (see HP#8 for a review of the CC-60) which prevents overcharging the batteries. Power storage is in six Trojan L-16W batteries with a total capacity of 1,050 Ampere-hours at 12 VDC. This storage is sufficient to run the system for over 5 days with no energy input. The L-16Ws are equipped with Hydrocap catalytic converters to reduce gassing into the house and water consumption (see HP#11 for a report on Hydrocaps). This system uses a 1.2 kW. Heart inverter/battery charger to convert the battery stored power into 120 vac for household use. Two engine/generators are used in this system. The first is a 120/240 vac Honda ES6500 generator. This unit produces 6,500 watts and can both directly source the system and recharge the batteries via the Heart inverter's battery charger. Jim had very good things to say about this two cylinder, overhead valve and cam, water cooled generator. He's found it to be very quiet, reliable and easy on fuel. The second generator in this system is a Mark VI type 100 Ampere, 12 VDC alternator setup. This powerplant uses a 5hp. Honda OHV single cylinder engine to turn a 100 Ampere Chrysler automotive alternator. The unit is controlled by Electron Connection's Mark VI alternator field controller. See HP#2 for a complete description of the Mark VI system and how to build one. The DC plant was used extensively to recharge the batteries before Jim & Laura installed their PV panels. Since the PVs arrived, both generators are getting a real vacation with only light use on the ES6500 and almost no use on the Mark VI system. Jim uses the ES6500 for large tools and Laura uses it on "cleanup days" when the washing machine, clothes dryer, and vacuum cleaner are all running at once. The spreadsheet and chart below show the costs of Jim & Laura's system. Please note that this cost breakdown includes all the power equipment used in the system. If the system were specified now, then at least one of the generators could be deleted. However, this system grew up before PVs were affordable and hence, extra generators. INSERT COST SPREAD AND CHART Several other aspects of Jim & Laura's system are interesting although they have nothing to do with electricity. Jim uses a Dempster wind powered jack pump to move water from his deep well to a holding tank behind the house. Jim & Laura's extensive vegetable garden is drip water and micro sprinkled from a gravity flow system sourced by nearby Camp Creek. Big Uns & Lil Uns Both the systems described here use PVs for power input and both store power in batteries. The cost and amount of power produced & consumed is different. The Big Un cycles about 2,000 Watt-hours daily and the Lil Un cycles about 500 Watt-hours daily. The higher cost of the larger system is due to its increased flexibility and capabilities. The Big Un uses an inverter (and the increased battery capacity to power it) that allows Jim and Laura essential 120 vac appliances like a computer & printer for their businesses, and appliances for Jim's kitchen wizardry. And other small essentials like a heater and bubbler for the fish tank (while this may not seem essential to some, it certainly does to the fish and 4 year old Saylor Flett who loves them). The Big Un also supports large appliances like a washing machine, gas fired clothes dryer, and a vacuum cleaner. The engine/generators assure that that Jim & Laura won't run out of power during extended cloudy periods or even extended visits from switch-flipping city folks. And there's good things to say about the Lil Uns too. Small stand alone PV systems are supremely reliable and very cost effective. The Lil Un delivers essential power for lighting and communications that otherwise have to be sourced by a noisy, expensive and unreliable engine/generator. The Lil Un is very reliable because it doesn't depend on complex, expensive electronics like an inverter, but uses power directly from the battery as 12 VDC. Since the only power input is solar, the Lil Un has virtually no maintenance other than occasionally watering the batteries. So, ya pays yer money and makes yer choice. The size, complexity and cost of a power system depends on what you require of it. Those with simple low powered requirements can have what they need for very little cost. Those requiring more will have to use larger systems that cost more. But the essential feature here is that you don't have to have any more than you need. And that's up to you to decide. FreedomÉ Access System Owners & Operators Jim & Laura Flett 19812 Camp Creek, Hornbrook, CA 96044 Bill & Jean Andrews Randcore Pass, Soda Mtn on Hwy 66., Ashland, OR 97520 System Specifiers, Vendors & Installers Electron Connection Ltd. POB 442, Medford, OR 97501 ¥ 916-475-3179