"I'd put my money on the sun and solar energy. What a source of power!
I hope we don't have to wait till oil and coal run out before we tackle that."
- Thomas Edison (1847-1931)

 

"STAND-ALONE"
SOLAR PANELS SYSTEM

DESIGN - INSTALLATION - COSTS - BACK-UP SYSTEM
SEPARATE 12 VOLT SYSTEM - FREE "PV" BOOKS

We had planned to have a system utilizing both electricity from the utility company and from our PV system. However,the local electric company wanted $5,000 to run the power in to us. That's after WE dug a four foot deep trench a quarter of a mile long for the cable. We said "no, thank you."

We are now "off the grid" -- relying totally on our own system of solar panels, charge controller, batteries, and inverter to generate electricity. The system works fine and, frankly, it's a good feeling to be independent from the power company and to be helping our planet by not contributing to the pollution from burning coal and natural gas used to produce conventional electricity.

From the power generated by our twelve solar panels (shown above), stored in twelve batteries, and converted to 110 AC household current with an inverter, we can run all of our city gadgets (though not all at once):

• lights

• stereo receiver, tape deck, CD/DVD player

• TV

• computer, printer/scanner, and satellite modem

• coffee pot and coffee bean grinder

• microwave oven

• vacuum cleaner

  small refrigerator

• 1/2 horse power pump to bring water to our house from the storage tank

• power tools

• concrete mixer to build the foundations for the greenhouse and straw bale house and mix earthen plaster and lime plaster for the house

• and other things...
  
  
  

SEPARATE 12 VOLT - DIRECT CURRENT SYSTEM

Since appliances, motors, and electronic devices all run more efficiently on direct current when compared with their AC counterparts, we have installed a separate 12 VDC system for the things we have which run with DC current. This system consists of one 40 watt solar panel and a large capacity, deep-cycle storage battery to provide direct DC power. The system currently supplies power for three of the five DC pumps which circulate water in our hydronic heating system and a large DC exhaust fan for the greenhouse. The pumps only use 10 watts each, but each pump is capable of moving an amazing three gallons of water a minute. The fan only uses 16 watts, less than half the wattage necessary to run an AC fan of the same size.

Click here for a detailed diagram of this system which also includes a charge controller, on/off switches and fuses, a 12 volt timer, and a battery desulfator.

The books listed below are highly useful resource materials for setting up your own solar electric system. They are all available FREE from Sandia National Laboratories. Log on to the Sandia Laboratories web site, then click on the "Publications" tab and download their publications list. Print out the list, check the books you want and send it back to them in the mail. Wait a few weeks and a small and highly valuable reference library will arrive on your door step. There are lots of great (expensive) PV books you can buy, but...

"Power Where You Need It: The Promise of Photovoltaics" by Connie Brooks - 50 pages, mostly photographs, of a large number of different applications of solar electric power, quite fascinating and informative

"Stand-Alone Photovoltaic Systems: A Handbook of Recommended Design Practices" - Soft cover, spiral-bound, 436 pages. Presents recommended design practices for stand-alone photovoltaic (PV) systems. System-level tradeoffs necessary for any PV application are discussed. Presented are: a system sizing method that can be completed without access to a computer, instructions and blank worksheets, and 15 specific examples of PV systems designed to meet a wide range of applications. Each example includes sizing, design, hardware specifications, installation description, and cost information.

"Maintenance and Operation of Stand-Alone Photovoltaic Systems" - Soft cover, spiral-bound, 247 pages. A guide for engineers, planners, maintenance supervisors, and all maintenance personnel involved in the operation, inspection, troubleshooting, repair, and maintenance of PV systems. It is designed to be used in the field by the personnel performing the actual inspection, maintenance, or repair of solar power systems.

"Photovoltaic Power Systems and The National Electrical Code: Suggested Practices" - Soft cover, spiral bound, 140 pages. This guide provides information on the NEC and how it relates to PV systems. It is not intended to interpret or replace the NEC; it merely paraphrases the NEC and aligns information contained in the NEC with PV subsystems. This material is not intended to be a design guide nor an instruction manual for an untrained person. Furthermore, it is not intended to cover all aspects of the NEC or PV systems--it must be used in conjunction with the full text of the NEC.