John Wiles’: NEC applied to PV, Code Corner articles

John Wiles NEC Code Corner articles http://tinyurl.com/57uqfj

PHOTOVOLTAIC POWER SYSTEMS and the NATIONAL ELECTRICAL CODE: http://tinyurl.com/59thse

Finish eating, drinking, or anything else that will get your computer dirty ….

http://quantumgravitics.tripod.com/id9.html

The care & feeding of your batteries, Diagonal Wire

So you have paid big bucks for your 30 batteries to run your house for a week, but after a month, they have all died. What went wrong?

Of course YOU DON’T WANT A CAR BATTERY!

A car battery is designed for short bursts of high output, for starting a car mostly.

You want a deep-cycle battery. They’re still 12V, but different sizes have different capacities. The Capacities are in Amp-Hours or AH. The higher the AH, the bigger the capacity (and the more expensive). If you go the roll-your-own route, take the advice here and buy a cheap costco deep-cycle, as you’ll probably kill it pretty quick.

Typically, for people who have large requirements, they get multiple batteries and wire them together.

Math Fun: Watts = Volts x Amps the “typical” 12V battery is rated at about 100 amps. You can safely use half of it, without damaging the battery. So a typical costco deep cycle battery holds 12v x 50a= 600 usable watts

How to wire for balanced voltage distribution (2 examples):

Why to “Diagonal Wire”: http://www.smartgauge.co.uk/batt_con.html

Several Different types

* Flooded (original style, open caps, add water)

* Gel

* AGM

* Spiral

* Starting

* Deep Cycle (Difference between Starting & Deep Cycle batteries)

All need to be recharged soon after being depleted, and none like more than a 60% discharge, the deeper the discharge, the more internal damage, and shorter the overall lifetime. Sitting discharged, sulfur crystals start to form, and they obscure the lead plates, reduceing capacity. (sulfation)

Hobbyist site (Bill Dardens Battery FAQ) http://www.uuhome.de/william.darden/

Commercial site explanation, but they are not the only answer http://www.battery-care.com/

EV’s are electric vehicles.

Some info about Plug-In Hybrids

http://www.eaa-phev.org/wiki/Plug-In_Hybrids.

“Can I charge my electric scooter by mounting a solar panel on the handlebars?”

A small solar panel in the 5-watt range looks great mounted to a scooter. Unfortunately, the capacity of such a panel is inadequate to support practical daily use.

“What size panel would be needed for a practial scooter solution?”

About 85-watts to 200-watts seems to work well during the Burning Man art festival. Panels of this size are too large for scooter handlebars, however, and would be best placed over a larger vehicle as a shade or pulled behind a scooter on a lightweight trailer.

Although the guideline above will work, it may lead you to obtain a more expensive panel than you need, or it may lead you to run down your scooter’s battery. It all depends on the size of the scooter (and you) and the amount of time that you plan on using it each day.

A more accurate determination requires you know the power usage of your moving scooter. If you or an electrically minded friend (an engineer–they’re good for something, you know) can measure the scooter’s current consumption in amps during operation, then multiply that number by the scooter battery’s nominal voltage in volts (usually 12 or 24). The product that you get is the scooter’s power usage in watts. Expect a quantity of a few hundred watts. Compare this value to the solar panel’s power capacity, which also is in watts. If they’re about the same, you can spend about half of the time running and half of the time charging. If the panel’s rating is smaller than the scooter’s power usage, then you’ll need to spend more time charging than moving.

The estimate above is another guideline, however, because it ignores the angle to the sun, dust, whether your scooter can charge and run at the same time, and other such details. The purpose of this estimate is to teach you that 5 watts ain’t enough, and 500 watts probably is a bit more than necessary.