How 4CP works
In each of June, July, August and September, ERCOT finds the 15-minute interval when total grid demand was highest. Those four intervals are the four coincident peaks.
The demand of a large customer during those four intervals sets its share of transmission costs for the following year. A customer that uses less during the peaks pays less.
Why large loads care
Transmission charges are a large part of the delivered cost of power for a big load. Some loads cut their use, or switch to on-site generation or batteries, on days when a peak looks likely. The peaks are only known for sure after the month ends, so this takes forecasting.
The method has been under review by Texas regulators. Check the PUCT for the current rule before building a business case on it.
Questions people ask
Does 4CP apply to every customer?
No. It mainly affects large customers whose transmission charges are based on measured demand during the peak intervals. Homes and small businesses are billed differently.
Can a data center avoid 4CP charges?
A load that can reduce grid use during the four peak intervals can lower its share. Whether that is practical depends on the workload and on any backup power on site.
Related
More glossary
- What is time to power?
- What is powered land?
- What is a powered shell?
- What is large load interconnection?
- What is a point of interconnection?
- What is an interconnection queue?
- What is queue position?
- What is ERCOT?
Need a site, or have one?
Tell us what you need and Voltane finds, reports on and prices candidate sites in ERCOT. Or bring a site you already have for a path-to-power report (by request for now).