Can someone explain how TVA calculates the power factor penalty under Schedule MSB? Our Huntsville facility is getting hit with charges but the tariff language is confusing. It mentions both 'average power factor' and 'monthly power factor' but doesn't clearly define the difference. Are they using 15-minute interval data or monthly averages? The penalties are about $800/month and I want to make sure they're calculated correctly.
TVA Schedule MSB power factor charges - need clarification
Albert, TVA uses the monthly average method for MSB schedules. They take your total kWh and kVARh for the billing period and calculate PF from those totals. It's different from some utilities that use interval averaging. The threshold is 0.85 for most MSB customers. If you're consistently below that, you might need to look at capacitor installation rather than fighting the calculation method.
Thanks Terry. That makes sense now. Our monthly PF has been running 0.82-0.84 so we're definitely below the threshold. I was hoping it was a billing error but sounds like we need to invest in power factor correction. Any recommendations for equipment sizing? We're pulling about 450 kW average with mostly motor loads.
For 450 kW with motor loads you'll probably need 150-200 kVAR of capacitance to get above 0.90 PF. Get a power quality survey done first though - don't just guess at the sizing. TVA actually offers rebates for power factor correction equipment if you meet their requirements. Check with your TVA account rep about the EnergyRight program.