Wendell T from Billings, MT. NorthWestern Energy territory. Found a bizarre one. My client is a grain elevator that was billed for February 2020 — a leap year with 29 days. The energy charges look fine. But the demand charge line shows two separate demand entries: one for 285 kW and one for 285 kW. The total demand charge is double what it should be. I pulled February 2019 (non-leap year, 28 days) and there is only one demand entry. Same for every other month. Something about February having 29 days caused the billing system to generate a duplicate demand charge.
Leap year caused a billing system glitch — February demand charges doubled
Wendell, leap year billing glitches are real and they happen every 4 years like clockwork. I have heard of this specific issue with older billing systems that were not properly configured for the 29th day. The system processes 28 days normally, then hits the 29th as if it is a new demand measurement period and generates a second demand charge. It is a software bug, pure and simple.
I check for this every leap year now. In 2016 I found the same double-demand glitch on two NorthWestern Energy accounts. They fixed it for those specific accounts but apparently did not patch the underlying system bug. Wendell, the fix should be simple — NorthWestern just needs to remove the duplicate demand charge and rebill.
Noel, good to know it has happened before. Called NorthWestern and they acknowledged the leap year bug immediately. Apparently it affected about 200 commercial accounts in their Montana service territory. They are processing corrections for all affected accounts, not just mine. My client credit: $3,192 for the duplicate 285 kW demand charge at $11.20/kW.
Here is the funny part — NorthWestern told me the same bug existed in 2016 and 2012 but they only fixed the individual accounts that complained. They never patched the root cause. So every 4 years, 200 commercial customers get double-billed for February demand and only the ones who notice get corrected. I asked if they would go back and fix 2016 and 2012 for my client. They agreed to check 2016 but said 2012 was beyond their data retention period.
A billing bug that has been known since 2012 and still is not fixed 8 years later. This is why our profession will never run out of work. Wendell, good job pushing them to check 2016 as well. Every four years that is another $3,200 they quietly overcharged 200 businesses.