Working with a warehouse client on FPL's GSD-1 rate schedule and these summer demand charges are brutal. They have six 40-ton package units that all seem to start up within minutes of each other around 7 AM. Peak demand hit 485kW last month vs normal 320kW. At $17.85/kW that's an extra $2,945 just for poor timing. Anyone dealt with similar staging issues on FPL?
FPL rate schedule GSD-1: HVAC demand charges killing us
Entergy New Orleans has similar issues. The key is randomizing start times and adding staging delays. We installed a simple time clock system that staggers startup over 15 minutes instead of everything hitting at once. Saved the client about $8K annually. Payback was under 6 months including installation.
OG&E has the same problem areas. Package units are the worst because they don't coordinate with each other. I recommend either a central control system or at minimum individual time delay relays. You can get basic staging for under $500 per unit if you're not looking for fancy controls.
Susan makes a good point about the simple approach. Client doesn't want to spend big money on a full BMS. The time delay relay option sounds promising. Are you talking about just delaying the compressor start or the entire unit startup? Want to make sure we don't create comfort issues.
PG&E territory here - we use Intermatic time switches with random start features. Delays the compressor only, fans can start immediately for comfort. Usually set delays between 0-10 minutes randomly distributed. Works great for package units that don't talk to each other. About $200 per unit installed.
Georgia Power just increased their demand charges again - now up to $19.50/kW in summer. We're seeing more warehouse and retail clients get serious about demand management. Pete's suggestion on the Intermatic switches is solid. We've installed probably 50 of those systems over the past two years with good results.