Got a metal fabrication shop in Huntsville that's burning through electricity like crazy. They're hitting 85 kWh per pound of finished product vs industry benchmark of 60 kWh/lb. Alabama Power bill last month was $34,500 on Rate Schedule LPL. Plant manager swears nothing has changed but the numbers don't lie. Where should I start looking? They run three shifts, mostly MIG welding and plasma cutting.
Manufacturing client using 40% more power than benchmark - help!
Albert, first thing I'd check is power factor. Welding equipment can really mess with your PF and Alabama Power hits you hard on that. We had a similar shop down here in Corpus Christi on AEP Texas that was paying $3,200/month in PF penalties they didn't even know about. Also check if they've added any new equipment recently - sometimes foremen don't communicate with management about smaller additions.
Vivian's right about the power factor. Also look at their compressed air system. We see a lot of metal fab shops here in Missouri that have leaky air lines driving up compressor run time. A 1/4 inch hole in an air line at 100 PSI wastes about 100 CFM continuously. That adds up fast on the electric bill. Empire Electric charges us time-of-use rates so inefficient compressors really hurt during peak hours.
Don't overlook the basics either. We had a fab shop in New Orleans on Entergy that was leaving half their lighting on overnight. Maintenance crew thought the lights were supposed to stay on for "security" but nobody ever told them which ones. Simple timer controls saved them $800/month. Also check ventilation fans - a lot of shops over-ventilate because they're worried about OSHA compliance.
Albert, are they doing any heat treating? We have a client up here in Omaha on OPPD that added a small heat treat oven and didn't realize it was pulling 150 kW continuously when in use. The oven manufacturer sold it as "energy efficient" but didn't mention it runs almost constantly to maintain temperature. Sometimes new "efficient" equipment uses more total energy than old stuff.
Good catches everyone. Ken, they did install a new normalizing furnace about 6 months ago. Plant manager said it was "more efficient" but maybe he meant more productive, not energy efficient. I'll get the specs on that unit. Vivian, I'll definitely check power factor - Alabama Power's penalties are brutal. Juan, you're right about the lighting too. I walked through at 6 AM and half the plant was lit up with nobody around.
Albert, another thing to check - are they pre-heating stock material? Some fab shops started doing this to improve weld quality but it's an energy killer. We had an OG&E client here in Oklahoma City that was running induction heaters on steel stock 2 hours before welding. Turned out they only needed 20 minutes of pre-heat for the same quality results. Saved them $1,400/month just on that change.
Susan brings up a good point about process changes. We see this a lot in New England where National Grid rates are so high. Companies make process "improvements" without thinking about energy impact. Sometimes going back to the old way of doing things is actually more cost-effective when you factor in utility costs.
Albert, I'm curious what you found with that normalizing furnace. We just had a similar issue here in Pennsylvania with a PPL client. The new furnace was rated at 200 kW but was actually drawing 240 kW because of poor installation. The electrical contractor didn't properly size the feeders and the voltage drop was making the heating elements work harder. Might be worth checking the actual draw vs nameplate ratings.
Sylvia, that's exactly what we found! The furnace was pulling 285 kW instead of the rated 225 kW. Turned out the electrical feed was undersized and they were getting significant voltage drop. Alabama Power actually helped us identify this during a power quality survey. Fixed the wiring and immediately dropped their usage by 12%. Sometimes the solution is simpler than you think.
That's great Albert! Love it when utilities actually help instead of just sending bills. PPL has been pretty good about power quality issues too. Did Alabama Power charge you for the survey or was it part of their commercial services? We pay about $1,500 for similar surveys from our local contractor but if the utility will do it for free, that's money saved right there.