KIDZ Station Setup

Please note: In November 2004 KIDZ and family moved from Denver, CO to Centerburg, OH.  What follows is a description of her station setup as it was in Denver.  Her new home site in OH is not really suitable for solar power, so solar is only being used on a very limited basis (powering an electric fence to enclose goats), and not for radios at the present time.  All radios have not as yet been set up in the new location.

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All amateur radios located in KIDZ's home are powered by solar energy.

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Description of KIDZ "Solar System"
Batteries PV Panels and Their Orientation List of Vendors Used
Battery Charger Charge Controller and Power Distribution System Recommended Reading

Solar energy is another hobby of mine and I've enjoyed using it with amateur radio. Though I live in a Denver suburb and my house is powered by Public Service I have chosen to use solar energy to power the hamshack as well as a Sunfrost cu-10 ft. deep freezer. I don't even own a power supply for the 12V radios. The HTs are usually powered by just their NiCd batteries which are charged by a cigarette lighter charger connected to the solar system.

Batteries

When designing a solar system there are some worksheets which may be used to help with system sizing. The official formulas indicated a need for 18 6V gold cart batteries connected in series and parallel to provide enough storage to overcome extended cloudy weather for my desired configuration. However, due to cost and weight concerns of the 18 batteries AND the fact that the solar system is backed up by utility power, I originally chose to use only four in series and parallel. Two additional batteries were added a year later. The Trojan-105 batteries are connected two in series to get 12V and each "set" connected in parallel to get 660 amp-hours. They original four were in service from July 1995 to November 1999 when it was decided to upgrade to four Trojan L16 batteries. They are in a very well ventilated, unheated, enclosed porch. The batteries are cleaned and equalized at least four times each year.

*Ordinarily one should expect more than five years' use from golf cart batteries if they are well maintained. However, the porch is not heated in the winter. The decrease in bank capacity due to cooler temperatures and degradation became unacceptable after four years. Cold temperatures, while prolonging a battery's life-span eventually can freeze aging batteries as the electrolyte's freezing temperature rises. Brand new lead acid batteries have a freezing temp of -40 . To help with this problem a styrofoam enclosure was constructed to insulate the batteries in the winter. 

The Trojan Web site has an excellent information on battery terminology as well as FAQs which include info on proper battery maintenance, selection, charging, and the effects of temperature.

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Battery Charger

Prior to the installation of the solar panels in August '96 a Todd Engineering PowerSource 30-amp charger was used to charge the batteries. They were kept in a constant float state. I highly recommend the Todd chargers. They are very kind to batteries and the company was very responsive to the one problem I've had with my charger. Todd manufactures charters with higher amperage values which, in turn, may be connected in parallel if a higher charging rate is needed. In addition to using utility power they can also be used on a generator, which is their most common use. Since installing the panels the Todd charger's function is only as backup power in the event of extended cloudy days or cold weather, or solar array damage. Typically it is only used about four times a year when the battery voltage drops below 12.2V (activation of the charger is controlled by the charge controller described below).  The main reason is extended cold weather (temperatures below 10 F.) or extended use of the inverter. 

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PV Panels and Their Orientation

A combination of six used Carrizo Super Gold panels that were dismantled from a power plant in California several years ago and two Solarex VLX53 panels comprise the solar array. The Carrizo panels measure one foot by three feet and three in series are needed to achieve 12V charging. Each group of three is rated at 105 watts. The Solarex panels measure 36.9 inches by 19.8 inches and are rated at 53 watts each and are hail and wind resistant. The total array is rated at 316 watts. Under excellent conditions I have seen the array generate as high as 23 amps and 16 volts for a total of 368 watts. This array was intentionally oversized for the load and storage capacity of the system. Since installation the array's performance has decreased dramatically. It is suspected that the Carrizo panels are the culprit. They were subjected to concentrators, which accelerate degradation, when installed at the power plant.

The array angle is adjusted four times a year with each change occurring about a month before the upcoming equinox or solstice. The panels are also cleaned with dish detergent and water at these times. The latitude, latitude +15, latitude -15 system is used. This means that the Spring and Fall angles are about the angle corresponding to my latitude which is just under 40. (Due to the limitations of the rack and the angle of the roof, the Spring and Fall angle is more like 46.) The Summer angle is latitude minus 15 or about 25 (in reality the rack and roof limitations give a 23 angle). The Winter setting is latitude plus 15 or about 55. An interesting note about the panels' efficiency is that mine generate more electricity in the Winter despite the indirect sun rays than in the summer. I believe this is largely due to the fact that cooler panels are more efficient than warmer ones. In this case the temperature outweighs the insolation. Another note is that though solar panels can sometimes charge a battery when covered by snow it is imperative that they be cleaned ASAP following a snowstorm for best results.

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Charge Controller and Power Distribution System

An Ananda Power Technology * PowerCenter 5 charge controller with Cruising's E-Meter is used. As an entirely self-contained power control center, it is much more than a charge controller. It has DC breakers, section to distribute AC power from an inverter, PV controller, and also calls on the Todd when needed (the Todd is plugged into the wall at all times, but is not powered unless needed). It has additional fuses, an emergency "pull-out" that will shut everything down if needed, and is UL listed. Though the Ananda cost more than more basic charge controllers, when safety, features, and ease-of-use is considered, I believe it was worth it. Managing the system and expansion of either the battery bank, solar array, or load is easy with the Ananda. The optional E-meter provides, at a glance, the battery voltage, net amps into the system, amp-hour deficit, and time remaining until disconnect (the Ananda will automatically disconnect loads when the battery voltage drops too low, however, in my case, it will activate the Todd before then so in reality this reading is useless unless there is a power outage). My Ananda was ordered with the optional temperature compensation feature. If batteries will not be kept near 77 F. temperature compensation is highly recommended. In colder temperatures the Ananda allows a higher voltage to reach the batteries than when the weather is warmer. Sixteen volts has been noted on very cold days, yet only 14 volts may be permitted on hot days. 14.7 is typical for 77 F.

* In October 1998 I discovered that Ananda Power Technology went out of business. I understand that Trace now produces products similar to APT's powercenters.

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A Whistler PP300AC inverter was added during the summer 1998.  It provides 300 watts continuous power (can run Pentium computer with printer, soldering iron, TV/VCR, or crock pot).

Since I'm active in ARES I consider my set-up an asset to amateur radio.

List of Vendors Used

I purchased my solar system components from:

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Recommended Reading

The following is a list of books I have personally used to design, implement, or maintain my solar system. They are listed in order of technical usefulness (subject to change):

* Indicates discount available on this book at Amazon books.

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Interested in solar car racing? Check out the American Solar Challenge (formerly known as Sunrayce).

Note: I am not connected with any of the companies mentioned in this article and receive no benefits for my recommendations.  I do receive a small commission on books purchased through this page, but I have not changed my recommended reading list to maximize income as a result of Beyond Infinity's alliance with Amazon books.  Since some of the books available on this page through Amazon are at a discounted rate, so I believe making them available for purchase here is a benefit to visitors.

Page last updated October 11, 2008.

Comments and suggestions concerning this page may be directed to KI0DZ@QSL.NET.

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