KC120 - 120 Watts $540.-
The highest output 36 cell module offered today! 120 watts in a single module cuts instulation cost and time. Operating voltage 16.9, Maximum power current 7.10 amps.
56.1 in. X 25.7 in. X 1.4 in. / 35 lbs.
(142.5 cm X 65.2 cm X 3.6 cm / 15.9 kg)
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KC80 - 80 Watts $360.-
Operating voltage 16.9, Maximum power current 4.73 amps.
38.4 in. X 25.7 in. X 1.4 in. / 27 lbs
(97.6 cm X 65.2 X 3.6 cm / 12.25 kg)
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KC60 - 60 Watts $288.-
The new standard for everyday solar applications. Very useful power output and size. Building block for residential and industrial applications. Operating voltage 16.9, Maximum power current3.55 amps.
29.6 in. X 25.7 in. X 1.4 in. / 24 lbs
(75.1 cm X 65.2 cm X 3.6 cm / 10.9 kg)
We can easily explain how the Photovoltaic effect produces a flow of electrons. In short, electrons are excited by particles of light and find the attached electrical circuit the easiest path to travel from one side of the cell to the other. Envision a piece of metal such as the side panel of a car. As it sits in the sun the metal warms.
This warming is caused by the exciting of electrons, bouncing back and forth creating friction and therefore heat. The solar cell merely takes a percentage of these electrons and directs them to flow in a path. This flow of electrons is, by definition, electricity.
THE BASIC IDEA IS SIMPLE
Photovoltaic modules (solar panels) convert sunlight into electricity. Wire conducts the electricity to batteries where it is stored until needed. On the way to the batteries, the electrical current passes through a controller (regulator) which will shut off the flow when the batteries become full. For some appliances, electricity can be used directly from the batteries. This is "direct current" and it powers "DC" appliances such as car headlights, flashlights, portable radios, etc.
To run most appliances found in the home, however, we need to use "alternating current" or "AC", the type which is found in wall sockets. This we can produce utilizing an inverter which transforms DC electricity from the batteries into AC. The inverter's AC output powers the circuit breaker box and the common outlets in your home.
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Photovoltaic Generation Systems
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Utility connected photovoltaic generation systems
In utility connected photovoltaic generation systems, the wiring from a photovoltaic generating system is connected to a utility line, and any surplus electricity generated during the day is sold to the electric company. Electricity required at night is purchased in the usual way.
Stand alone photovoltaic generation systems
A stand alone photovoltaic generation system stores generated electricity and then distributes it as necessary. This system is often used independently, and can be installed with little difficulty anywhere there is sunlight.
Array direct photovoltaic generation systems
Solar cells can be connected directly to devices requiring electricity (without an intermediate battery). With this kind of system, electricity is available only when the sun is shining on the cells. Such systems are often used to drive fans and pumps.
Give yourself the power to go anywhere
with the most powerful charging systems under the sun.
Many people who choose RV Solar Electric systems are looking for a way to have dependable electricity even when parked far from the closest plug-in. The reason people give for being happy with an RV solar system is because it is quiet, or because it is less expensive and less complicated than a generator.
Since batteries are charged when traveling, RV's normally depend mostly on the vehicle's alternator for the primary power source. Power to charge the battery bank is also provided through a converter when plugged into the utility. However, for those who like to spend days, weeks (or longer) not traveling and not plugged in, photovoltaics can mean freedom. And, because a PV array can put as much power into your batteries during an hour of bright sun as a small gasoline generator, it can also mean reclaiming peace and quiet. As well, the RV's existing battery bank and fuse box make the transition to solar a smooth and economical one.
While most of our RV systems utilize 1 to 3 modules, it is important to analyze your power needs. Just as with all PV systems, you need to consider the wattage of the appliances and lights you are powering as well as the average hours used each day. Average daily usage can be calculated on the worksheets in the appendix. Unlike most other systems, however, RV's travel through different regions of climate, park at varying angles to the sun, sometimes in shad e and sometimes not. People with similar vehicles can have very dissimilar power usage and patterns of travel. These factors should be considered. If you have any questions about how to go about this, please give us a call.
Most of our RV systems are sized to power average daily loads in average conditions. Determine where you will spend the most time "boon-docking" for three days or more and in what season. Find this on the map of sun-hours and make this your "available-sun-hours" entry on the worksheet. If the modules are mounted flat on the roof, they will put out about 70 percent as much as if aimed perfectly at the noon-day sun, so multiply sun hours by .7 for your worksheet entry.
Some of our customers have chosen to install an extension cord for their modules so that they can park in the shade while the array sits in the sun. For added durability and ease of handling, the "lite" modules on page 34 can be used. Ask us for tips on this type of arrangement.
Air conditioners require a very large array and are seldom powered by PV. Microwaves are okay, but require an inverter as do any other 110 volt AC appliances. When sizing, don't forget heater blower fans if you use them. Refrigerators that run on both propane and electric are very inefficient when run on electric. Any kind of electrical resistance heat is out, with the exception of occasional hair blowers or toasters.
WINDMILLS:YESTERDAY'S ANSWER TO REMOTE WATER DELIVERY
There are still thousands of windmill water pumping units standing in the western U.S. Regrettably, many are inoperable. These pumpers were very valuable for remote (off grid) sites, with the proper minimum wind conditions, when man-power was plentiful and cheap. Windmills, though potentially long lasting, need dedicated maintenance. The downhole leathers require inspection and high winds can cause mechanical damage to the blades. Parts for these mills are expensive and sometimes hard to find.
Solar water pumping systems have many advantages over windmill water pumpers. Though the initial cost of solar powered systems can be similar to that of windmills (however, in many cases far less!), the lifetime costs are much lower. Windmills must be used where there is a steady, constant wind for maximum results while solar powered pumps operate anywhere the sun shines. Solar pumping systems can be installed in less than a day by an individual or small crew and can be portable, while windmills (because of the need to erect a tower) can take a larger crew a much longer time to install. Windmills are secured to the ground and are stationary. Solar powered water pumping systems are the modern day, upgraded version of the windmill - using natural resources to deliver water in off grid locations.
GAS-FIRED GENERATORS VS. SOLAR ENERGY
Generators are commonly used to provide power beyond the powerline.
We have several economic studies concerning the economics of solar versus generators as a power choice. These studies consider all costs involved: modules, mounting structure, pumps, miscellaneous components, installation, operation, maintenance, yearly inspection, component replacement and salvage value. With this we can deter-mine a life cycle cost and a present value. One such comparison was done by the Bureau of Land Management at Battle Mountain, Nevada, specifically comparing solar water pumping systems to generator systems. For one 3.8 gpm system with a 275 foot design head, the PV system cost only 64% as much over 20 years as the generator system did over only 10 years. This remote solar site also used only 14% as many labor hours.
In 1989 Sandia National Laboratories noted that photovoltaic pumping systems in remote locations would often be cost effective compared to generators, even with 5 times the initial capital cost. Low end generators, which are initially inexpensive, require consistent maintenance and have a design life of approximately 1,500 hours. Small to medium sized solar pumping systems often cost less initially than a durable slow speed engine driven generator.
Most larger pump systems cost more initially than generator systems, but tend to be far more economical in the long run.
SOLAR PUMPS VS. GAS-FIRED GENERATORS & WINDMILLS
PUMP TYPE ADVANTAGES DISADVANTAGES
Solar electric power systems low maintenance
Clean
No fuel needed
Easy to install
Reliable long life
Unattended operation
Low recurrent costs
System is modular and can be matched closely to need
Relatively high initial cost
Lower output in cloudy weather
Diesel (or gas) power systems Moderate capital costs
Can be portable
Extensive experience available
Easy to install
Needs maintenance and replacement
Maintenance often inadequate, reducing life
Fuel often expensive and supply intermittent
Noise, dirt and fume problem
Site visits necessary
Windmill Potentially long-lasting
Works well in windy site
High maintenance
Costly repair
Difficult to find parts
Seasonal disadvantages
Need special tools for installation
Labor intensive
No wind, No power
Solar Electric Systems Definitions & Glossary
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Definitions and explanations of terms and words used when working with solar electric systems.
AC-Alternating current. Electrical energy which reverses its direction at regular intervals.
AC Daily Power Budget- The daily amount of watts your AC appliances use.
AC Inverter and Battery Power Allowance- Running an inverter draws a small amount of power from your battery. So does keeping power stored. The inverter and battery allowance in your power calculations help make certain enough power will be produced to keep your battery from running in the red.
Adjusted Total Daily Power Budget- A total daily power budget may be changed to meet certain situations. For instance, if you spend only weekends at a house, then your adjusted total daily power budget will be lower. Adding a generator to your system also reduces your total daily power budget. The adjusted daily power budget provides the figure that determines the size of you solar electric power system.
Ampere or amp- Electric current is measured in amperes or amps.
Amp Hours The number of amps used or produced in a given hour equals the number of hours. Batteries are rated in amp hours.
Array A group of solar electric modules connected together in a power system.
Battery Bank A group of batteries wired together to store power in a solar electric system. Allows you to use the stored power at night, on cloudy days or to run more power than the array can produce at one time.
Centrifugal (Water Pumping) Rotating outward, away from the center, as in centrifugal force.
Controller _ Simply put, the controller regulates the current from solar charger to your battery bank.
Current The rate of flow of an electric charge. Current is measured in amps.
DC Direct current. Electrical energy flowing in one direction and of substantially constant value.
DC Daily Power Budget The number of watts your DC appliances use daily.
Fall (Water Pump/Hydro Sections) The vertical descent of water, usually measured in vertical feet. Also called "head".
Flow Rate Speed at which water moves.
GPM Gallons per minute.
Ground Mount A piece of equipment upon which solar modules are mounted.
Head See "Fall".
Hertz or HZ The frequency of electrical current described in cycles per second. Appliances in the U.S. use 60 HZ. Appliances in other countries generally use 50 HZ.
Hydroelectricity Electricity created by water power.
Hydrometer An instrument used to measure state-of-charge (voltage) of a battery.
Inverter An Appliance used to convert independent DC power into standard household AC current.
Kilowatt or KW a thousand watts. (See Watts.)
LED Light emitting diode. These lights are often used to indicate low power on modern electronic equipment.
Line Loss Voltage drop over the length of electric line wire. Line loss robs your system of power when wire is too small for the load being run through the line or when voltage is too low for the distance the power must travel.
Load The lights or appliances run by your electrical system.
MA Milliamps, 1000 MA = 1 amp.
Module Modular solar electric charger; used interchangeably with solar electric panel.
Parallel Wiring A system of wiring, for solar electric modules of batteries, which increases amperage. Parallel wiring is "+ to +" (positive to positive) and " to " (negative to negative).
Photovoltaic Converting light into electricity. Photo means "light" voltaic means "electric". Often referred to as "PV" for short. More commonly referred to as "solar electric".
PSI Pounds per square inch.
Self-Regulating Some modules have a special circuitry which keeps the battery from overcharging. This means that no controller is needed when the self-regulating module is properly matched to battery storage capacity.
Series Wiring A system of wiring, for solar electric modules or batteries, which increases voltage. Series wiring is + to (positive to negative).
Single-Crystal Silicon Many solar chargers use single-crystal solar cells as they are the most efficient cell on the market. Pure silicon is grown into crystalline ingots which are cut into thin slices to make solar electric cells. These cells are then soldered together to meet the chargers voltage and current requirements.
Solar Cell The smallest basic solar electric device which generates electricity when exposed to light. Solar Electric The preferred term used to describe something which uses sunlight to produce electricity. "Photovoltaic" is the more technical term.
Thin Film Silicon The tiny solar chargers found in calculators and wristwatches are solar thin-film. Thin-film solar chargers are made by spreading a micro-thin layer of silicon on glass and creating the voltage and current circuits using laser technology. Thin-film chargers are produced in sizes from the microscopic calculator chip, up to the 1x4 power module.
Total Daily Power Budget In a DC system, the daily amount of watts your DC appliances use, plus the battery power allowance. In a DC and AC system, the daily amount of watts DC and AC appliances use, plus battery and inverter power allowances.
Voltage or Volts Voltage is the rating of the amount of electrical pressure that causes electricity to flow in the power line. If electricity were water, voltage would measure the amount of pressure at the faucet.
Watts A watt is a measurement of total electrical power. Volts x amps = watts.
Watt Hour The quantity of electrical energy used or produced when one watt is used for one hour.