Lightning Protection
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Lightning Protection |
 A cathodic protection system near Canadian, Texas, 8 Amp |
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Note: This is just an approximation with most figures rounded off. The actual cost might vary a few hundred (10%)either way, depending on actual components used, quantity purchased, or special requirements and options. What a "real" CP system will cost you
The ground bed needs 50 watts. You have 5.5 hours of sun (worst case typical winter). You need to provide 1200 watts per day to the ground bed (50w x 24 hours). For best efficiency, we will use both a Power Tracker charge control and a Power Tracker CP control. You need 1200 watts per day, and you have 5.5 hours in which to get it. 1200 divided by 5.5 - 218 watts per hour. Add safety factor: assume 300 watt panel array. For Farmington, you can use 4 days autonomy: 1200 watts x 4 days = 4800 watts battery. Go with 60% max discharge for very long battery life = 4800 divided by .6 = 8KW battery. A Concorde PVC-8D is a 12 volt, 300 AH (at 100 hour rate) battery - this equals 3600 watts. 2 batteries will be sufficient (note 1). So, what you have now is that you need 6 each 75-80 watt panels, and 2 300 AH batteries. In addition, you will need a mount for the panels, a power and CP control system, and a few odds and ends (wiring etc) Panels: $2600 Total cost of system will be about $5,300, but can vary depending on exact components. Expected maintenance is zero, except for battery replacement in 5 to 7 years. Use of premium quality batteries, such as the Surrette KS series would extend that to around 12 to 15 years. Since the system design is very efficient, if you can get your ground bed resistance down by 50% (a 25 watt ground bed), system costs would be about 40% less. Note 1: because we have already added in a large safety factor, the difference between 7200 and 8000 watts of battery storage can be ignored. |