Tom Andel

Get a charge out of this
June 18, 2008

My fellow blogger, Bob Trebilcock, just posted a Briefing on load building. It’s all about making best use of space and transportation dollars. I have a similar story to tell about space efficiency and transportation dollars, but the transportation I’m talking about goes on inside your building and it’s powered by electricity.

Most of you have been using electric transportation for years—in the form of forklifts. What does this have to do with space efficiency? Think how much space and energy is devote to keeping those vehicles running. You have a battery changing room and you pump a lot of human energy into pushing and pulling batteries in and out of those vehicles every day. But what about the electrical energy you’re pumping into those batteries? It comes at a price, but it’s a price you have more control of than you may know.

Richard Cromie is trying to spread that message to lift truck fleet managers in California. He’s with the Electric Transportation Dept. of Southern California Edison, and he was on a panel with me during last week’s “Greening of the Supply Chain” conference in Sacramento. He wants customers to make better use of the power they’re buying, and while fast charging is a more time and space efficient means of charging lift truck batteries, the timing of that time is everything.

First, an explanation for the uninitiated: fast charging is a very high power means of charging a depleted forklift battery from 20% state of charge to 80% in as little as 15-20 minutes. It pumps a lot of juice in real quick. That’s good because you can use fewer batteries and reassign a lot of the space dedicated to battery changing. However, if all your operators end up charging their battery at 12:30 during lunch, Cromie says your power costs will go through the ceiling.

“You have to be careful about using those high power chargers during the most expensive part of the day,” he said. He recommended ways to “power shift” to non-peak hours. He told how 200 Southern California Edison customers shifted 21 megawatts of power to overnight hours and saved a total of $6.1 million over five years. This does require some work on the user’s part however:

• Know your battery charging load profile

• Demand better charger power factors (>95%)

• Demand advanced charger controls & idle “power-off” feature

• Understand how to use your electric tariff to reduce costs

• Understand and use utility incentives effectively

• Consider “smart” batteries and battery management systems.

As for space efficiency, I just finished writing Modern’s August cover story on Polaris, one of the leading manufacturers of Sport Utility Vehicles. They use battery-powered  tuggers to supplement lift trucks in delivering in-process parts to assembly cells. The tuggers not only reduced lift truck traffic and downtime, but they increased productivity on the production lines. Part of Polaris’s productivity is owed to the use of fast chargers. The company not only eliminated extra batteries and the need for battery changing, but it freed up more production space as well.

Contact your local power provider to see if there are incentives available for this kind of efficient use of electricity. If you’re already making use of such incentives, blog back about it. Let’s spread the word about the power consumers have to save money on their power. (And don't miss Modern's August issue.)

Posted by Tom Andel on June 18, 2008 | Comments (2)