Lift Truck Tips: California charges ahead
California, the birthplace of the Energy Star program, is again advancing energy efficiency following the state energy commission’s Jan. 12 approval of efficiency standards for battery chargers.
According to Kenro Okamoto, electric product planning specialist for Toyota Material Handling, the new regulations require big changes for some electric lift truck users in California. They might also forecast a nationwide model for efficient forklift battery charging.
“These new regulations are going to force electric lift truck end-users to change,” says Okamoto. “So much charging technology is not smart. There’s a lot of waste.”
The commission estimates the 170 million charging devices in California homes and businesses account for as much as two-thirds of the 8,000 gigawatts consumed in the state each year. Unlike industrial chargers, most chargers for personal electronics do not automatically switch off at the end of the charging cycle. The new regulations will change that, but personal electronics will not likely be the primary source of savings. After all, not many cell phones have been in use for 10 or more years.
By the time the regulations are fully phased in, they could save California an estimated $300 million in annual electricity costs. Any industrial chargers that do not meet the regulation’s requirements for power conversion, power required to charge, no-battery draw, and overall efficiency will have to go.
“The older ferro-resonant technology is still in use because it is so reliable,” Okamoto says. “Even though it is heavy and inefficient, it just hasn’t been a squeaky wheel.”
Users might convert to next generation ferro-resonant technology, which uses power switches to improve efficiency, but this technology is not sensitive to input voltage. Therefore its overall power conversion efficiency (the difference between AC power at the wall and DC power at the battery) might not comply with the new regulations.
The safest bet, says Okamoto, is “switch mode” technologies such as IGBT or MOFFET. These high-frequency technologies are smaller, quieter, and much more efficient thanks to intelligent switching systems. The efficiency of such systems is much greater, but the increased complexity can also lead to increased service costs, says Okamoto.
“You have precise control, which enables great efficiency,” he adds. “They can perform with a variety of line voltages, no heavy expensive transformers have to be used, and power output is very efficient.”
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