What are the advantages and disadvantages of gel, AGM, and flooded lead acid deep cycle?

March 18, 2013

Generally, gel and AGM batteries have about 20% less capacity, cost about two times more, and have a shorter cycle life than comparable flooded lead acid batteries. However, Gel and AGM batteries do not need watering, are safer (no acid spilling out), can be placed in a variety of positions, have a slower self-discharge characteristic, [...]

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Can I use my deep-cycle battery as a starting battery?

March 14, 2013

Deep-cycle batteries can be used for engine starting but starting batteries should not be used for deep-cycle applications. A deep-cycle battery may have less cranking amps per pound than a starting battery, but in most cases a deep-cycle battery is still more than adequate for the purpose of starting an engine.

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What is the difference between a deep cycle battery, a starting battery, and a dual-purpose battery?

March 10, 2013

A deep-cycle battery has the ability to be deeply discharged and charged many times during its service life. It is designed specifically for powering electrical equipment for long periods of time. An automotive or starting battery is designed for brief bursts of high current and cannot withstand more than a few deep discharges before failure. [...]

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Graphene Can Create “Hot Carrier” Cells for Photovoltaics

March 8, 2013

Graphene’s potential applications in photovoltaics (PVs) have remained fairly limited. Nanomaterials of nearly every stripe, including quantum dots, nanowires and carbon nanotubes, have offered alternatives in the solar collecting cells of PVs. But research has really only offered graphene as a replacement to indium-tin-oxide (ITO) used in the electrodes for organic solar cells. Now researchers [...]

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10 Smart Ways We Could Stop Wasting Energy

March 7, 2013

Once you know where to look, it’s everywhere – dissipating, leaking away, drifting up in a puff of smoke. “When I see exhaust pipes and chimneys, I see wasted thermal energy,” says Chris Nelson, president of Cyclone Power Technologies in Pompano Beach, Fla. Nelson, whose father, Richard, co-founded Cogenic Energy Systems, a pioneering combined-heat-and-power company, [...]

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Sun-Powered Sundays: Solar Comes to the NFL

March 6, 2013

A ribbon of glowing Jets-green shone around the top rim of MetLife Stadium last night. Later, the ring turned big blue for the New York Giants, a nod to the fact that two teams share not only a $1.8 billion stadium but also that stadium’s newest gee-whiz feature. The ring is the work of NRG [...]

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Brazil Doubles Down on Biofuel

March 5, 2013

Later this year, northeastern Brazil will host one of the most ambitious biofuel experiments ever. There, in the small town of São Miguel dos ­Campos, surrounded by sprawling sugarcane fields, a commercial-­scale ethanol plant is expected to start operating in December. Unlike the nearby ethanol plants, which use sugarcane as feedstock, this new facility will [...]

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2012 Renewable Energy Recap: Renewables Reality Check

February 12, 2013

This year, the United States installed wind capacity passed the 50 GW milestone, while solar power continued a meteoric rise as well, now upwards of 6 GW installed. After a couple of years of massive resource assessments and grandiose thinking on renewables, though, 2012 seems to have been a year when we confronted the difficult [...]

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AC Grounding

February 8, 2013

As in any separately derived system, both parts must be properly grounded. There is usually no internal bond between the ac grounded circuit conductor and the grounding system inside either standalone or utility-interactive inverters. Both of these PV systems rely on the neutral-to-ground main bonding jumper in the service equipment (utility-interactive systems) or the bonding [...]

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Inverter AC Outputs

February 7, 2013

The inverter output (120 or 240 volts) must be connected to the ac distribution system in a manner that does not create parallel paths for currents flowing in grounded conductors [250.6]. The NEC requires that both the green or bare equipment-grounding conductor and the white ac neutral conductor be grounded, and this is normally accomplished [...]

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