Solar Sell

AstroPower solar cells are an easy sell. Quite simply, we supply the best value in solar cells and power modules...anywhere. As a market-driven, product-oriented company, we focus exclusively on supplying the solar products you need, at the best price.

Solar Cells

AstroPower's AP-105 and AP-106 solar cells are high-efficiency five and six inch single crystal solar cells, respectively. They are the largest and most powerful solar cells available today, rated between 1.5 and 3.3 watts each. Our new APex™ six inch polycrystalline silicon solar cells use our patented SiliconFilm™ technology for high-speed, large-area fabrication of solar cells at low cost. Large solar cells are more cost effective.

PV Modules

AstroPower's PV modules are available in rated powers up to 120Wpeak, and are the perfect solution for home power applications. The modules utilize industry standard construction techniques, and are certified by both Underwriters Laboratories (UL 1703) and international (IEC 1215) specification.

Panels

These products are designed specifically for systems requiring large arrays. AstroPower's panels provide the largest increment of pre-tested, pre-wired power available on the market-up to 480 watts per panel-and they can still be handled and installed by two people. Uncrate them, mount them, plug them in, and you're up and running. much quicker and easier than field assembly.

For more information about AstroPower or any AstroPower products, please call 302^366^0400 or e-mail us at [email protected].

AstroPower y<?J. KO HO NV^NU

The Large Solar Cell Company

Solar Park Newark, DE, USA 19716-2000 Tel: 302-366-0400 Fax: 302-368-6474

A so'Jar-po wered

Deep Well Pump

"' Urn cmMuBm

and Ellen Coleman

Above: Allie and Jessica Coleman pump water from underground tanks into the mobile tank.

r r f itting water at 900 feet (274 m) was great, but how could we get it out of the ground without grid energy? Most folks we talked with said it couldn't be done, but it just took a little figuring. Our off-grid community in northern New Mexico now enjoys all the water we need without resorting to power lines or gas generators.

Buying Land in the Boonies

Six years ago, our family moved onto 20 acres of semiarid, undeveloped land. We built an off-grid, environmentally conservative "Earthship". This is a thermal mass building that self-heats and cools, collects water, generates electricity, grows food, and provides shelter. Since we moved here, thirty more 20 acre lots have been bought around us, and five other homes have been built—two other Earthships and three straw bale houses. All are solar-powered and make use of water catchment systems.

Wow, It Doesn't Rain Much Here

We soon realized that despite our conservative use of water, we would need another source besides rainwater. The real estate broker had anticipated that the community would need to be off-grid, but he didn't give us accurate information about the rainfall and depth of underground water. Actually, we're in an interesting spot geographically. We're on the high semiarid mesa 30 miles from the verdant New Mexican village of Taos, which is fed by mountain streams and acequias (irrigation ditches). But the rain clouds often just put on lightning shows for us, and then rain on the mountains twenty miles east of us.

The groundwater at our property is 900 feet (274 m) below the surface. People who live in Taos, with groundwater only twenty feet (6 m) down, viewed our land as good for nothing more than grazing sheep and cattle. But the price was right ($19,000 for 20 acres), the views spectacular, and we were able to build what we wanted without a mortgage. To take a walk here under the big sky is like meditating without having to sit still. We buy a little propane for cooking, but other than that, there are no utility bills. We took a risk buying undeveloped land, but solar technology provides for our electrical needs and solved our water problems.

Solar Turned High Risk Into Homestead Equity

Three years ago, our community of landowners voted to change our "electrical escrow account" into a water drilling account. We decided to drill a community well so that we can haul water when our individual catchment systems are inadequate. With our solar-powered homes working just fine, we had no need to bring in electricity from the highway three and a half miles (5.6 km) away.

It may sound odd, but none of us were interested in piping the water from the well into our houses. We prefer to use the well as a backup to our catchment systems and to limit water use by the slight inconvenience of hauling it in a 1,000 gallon (3,785 liter) tank. We also made a group decision to power the well with photovoltaics if at all possible. Nobody wanted to deal with maintenance of a gas generator, much less the noise and having to haul gasoline. As a dealer of solar electric equipment, I was elected to design and troubleshoot the system that we would need. We wanted a relatively maintenance-free, safe, and easy system, with equipment that old or young people could handle.

While the well was being drilled, I began searching for the equipment to get the water out of the ground. There was a lot of hoopla the day the well driller hit water at 900 feet (274 m). He put down a temporary pump and powered it with a gas generator to bring up the first

Below: Jessica outside the straw bale power shed/wellhouse.

ATrombe wall keeps the batteries at good operating temperature.

Above: The thirty Carrizo SG 105 PV panels.

sample of our water. But the day I celebrated—all alone—was the day that I hooked up our solar equipment to the pump and saw the cool wet stuff come pouring out of the pipe.

Pumping and Hauling

Finding the right equipment to get water up from 900 feet (274 m) was a bit challenging, not to mention that I had to design the system for the future when usage would grow. DC pump systems couldn't deliver the necessary projected flow rate from that depth. The well suppliers I contacted were familiar only with grid and gas generator power systems. It seems that powering a deep well with PV with the flow rate that we needed had never been done before. Working with Steve Secrest of Golden Genesis, Inc., I designed a system (see schematic) that the spec sheets said would work. Now that it's up and running, we've seen that our system works very well indeed.

A Gould two HP 220 VAC pump gives us seven gallons (26 liters) per minute. We have 150 feet (46 m) of artesia which means that although we didn't hit water until 900 feet (624 m), the natural pressure is enough to fill the line up 150 feet (46 m) from there. Our pump is at 850 feet (259 m), which gives us 100 feet (30 m) of buffer in case the level ever falls. We have one-way check valves on the top of the pump and at 200 foot (61 m) intervals up the line. This is to avoid having the water fall all the way back to 750 feet (229 m) when the pump turns off. So there is a standing column of water ready to move into the storage tanks as soon as the pump is turned on. This also saves wear and tear on the pump and the inverter because the surge is lessened.

When the water reaches the surface, it is stored in six interconnected 3,000 gallon (11,356 liter) galvanized steel tanks. For

Above: The Colemans' garden benefits from the backup water supply.

insulation, the tanks are buried and bermed with earth. The 18,000 gallons (68,137 liters) of storage and our pumping capacity will provide 2,000 gallons (7,571 liters) a month for 30 landowners if necessary, though our usage is well below that at present.

When a landowner needs to haul water, the water from the storage tanks is pumped into a 1,000 gallon (3,785 liter) mobile tank (permanently set on a trailer). We use a 65 gallon per minute (gpm) sump pump set down in one of the steel storage tanks. The landowners drive the trailer to their own homes and pump the water into their own cisterns, using a 120 VAC, 60 gpm jet pump, or a gas driven irrigation pump (for folks who don't have their PV systems up and running). Both of these pumps are mounted on the tank-trailer.

Below: The earth-bermed north side of the Colemans' Earthship shows the rain water catchment system that is the primary water supply.

Our "Solar Farm"

Both the deep well pump and the tank-trailer pump are powered by what we call our "solar farm". Thirty Carrizo SG 105 solar panels are mounted in three 24 VDC arrays. They sit three feet (1 m) off the ground, above our maximum snow depth. The Carrizos are used panels, originally unmirrored Arco ML 52s which Carrizo Solar resold as Super Gold 105s.

Energy is stored in twenty 6 volt golf cart batteries wired in series/parallel (five groups of four). APT Technologies (now Pulse Energy Systems) put together a power center with three array disconnects, lightning arrestors, and metering for the system. A Vanner 3600 watt, 220 VAC sine wave inverter provides the power needed to run the pumps.

The batteries, inverter, metering, and safety equipment are stored in a ten foot by twelve foot (3 by 4 m) stuccoed straw bale building. ATrombe wall—a passive solar-thermal storage wall—on the south facing wall provides extra heat for those below-zero nights. During our cold winters, temperatures can drop to minus 25° F (-32° C), and we really notice the decrease in capacity of batteries kept in uninsulated areas. Battery maintenance is shared by landowners. We plan to add Hydrocaps in the future to ease this burden.

When the deep well pump is running, it draws 145 amps at 24 volts. Our panels put out 110 amps at 24 volts at their peak. The panels don't put out as much as the pump uses, and they don't have to. The battery bank provides 1100 amp-hours at 24 volts, which buffers and supplements the panel output. A timer cycles the pump on and off so that the battery bank can recharge periodically when the deep well pump is being used.

With our current setup, someone has to monitor sunlight conditions when the deep well pump is needed because the system does not recognize when there is not enough sunlight to recharge the batteries. The system shuts down when the batteries are at low voltage and has to be started back up when the sun has provided sufficient charge in the

Custom APT power center

Thirty Carrizo SG 105 photovoltaic panels, 110 amps peak at 24 volts

AC main box

Timer

Proposed

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