Calendarization & Normalization Steve Heinz, PE, CEM, CMVP Founder & CEO EnergyCAP, Inc.
Calendarization
EnergyCAP Reporting Month Each utility bill is assigned to a reporting month when entered, called the Billing Period. Example: A bill for April 20 May 20 is assigned to Billing Period of May because a majority of the days are in May even though 1/3 rd of the consumption was in April. Note: This default BP assignment is editable in manual bill entry and in bill import files.
EnergyCAP Reporting Month A 60-day water bill for April 20 June 20 will be called a May bill (May being the reporting month); April and June will report zero consumption. For some purposes, smoothing out bills to the calendar month in which the consumption occurred is preferred.
This process is called Calendarization
Why Calendarize? Better month-to-month and year-to-year comparisons Smooth out multi-month bills More representative of actual monthly energy usage even though utility bill meter readings do not align with calendar month dates
Why Calendarize? (cont d) Better reports and graphs Improved Budget Worksheet Fewer false alarms and wasted investigation time Available only in EnergyCAP Online versions
Calendarization Process
Non-weather sensitive meters Simple average daily use and cost allocation Spread it out based on days in each calendar month
Non-weather sensitive meters The actual bill is Dec 23 to Dec 25 (note: last day is ignored) Each day has the same allocated usage
Weather sensitive meters Split bill into weather sensitive and non-weather sensitive pieces Simple per day allocation of non-weather sensitive piece Degree day proration of weather sensitive piece
Weather sensitive meters The actual bill is Jul 23 to Aug 23 (note: last day is ignored) The non-weather sensitive portion is the same The weather sensitive portion is dependent upon the weather (the degree days) on each day
Most important concept: On an annual basis, the use and cost totals of calendarized data are equal to actual utility bills (exception: possible year-end rollover)
Calendarization is a better way to report and display the data unless you need to: Discuss actual bills with the vendor Reconcile actual bills with accounting functions Use actual bills to charge tenants, departments or reimbursable activities for their portion of utility usage
Non-Calendarized Quarterly Water Bills
Calendarized Quarterly Water Bills
How do we determine weather sensitivity? Similar to Cost Avoidance (M&V) Statistical correlation of usage vs. degree days Summer and winter analyzed separately Results visible for each meter Even a weather-sensitive meter is seldom 100% weather sensitive. A portion is non-weather base load and a portion is weather sensitive HVAC load
Weather sensitivity
Normalization
Why Normalize? Better year-to-year comparisons of usage (only) Shows energy usage reduction attributable to your efforts, not due to year-to-year weather variations Very valuable in long-term EUI charts to see real energy use reductions over time Available only in EnergyCAP Online versions
Normalization Process
Most important concept: Normalization shows estimated (hypothetical) data How much would I have used if the weather had been equal in every year to 2012?
Non-weather sensitive meters Simple average daily use and cost allocation No adjustments are made Spread it out based on days in each calendar month For non-weather sensitive meters, normalized data=calendarized data
Weather sensitive meters Split the bill into weather sensitive and non-weather sensitive pieces Simple per day allocation of the non-weather sensitive piece Degree day adjustment of the weather sensitive piece, using the degree days of the user-defined normalization base year (Administration>Normalization) Note: Use Weather Data Depot to find a typical degree day year as the base year, don t use an extreme year.
WeatherDataDepot.com helps find an average year
Simpler Normalization Process Possible? Q: Wouldn t this be a lot simpler if I just divided my total usage by total degree days, to give me a simple usage per degree day index? A: Yes, it would be simpler. It would also be totally invalid, so don t waste your time doing it.
Simpler Normalization Process Possible? (cont d) The divide all usage by degree days assumes that 100% of usage is weather sensitive But, you don t want to make weather adjustments where weather has no impact on a meter s usage (this causes over-adjusting) and almost no meters are 100% sensitive
Normalization Result #1 Monthly Use Graphic
Normalization Result #2 Annual Use Graphic
Normalization Result #3 Energy Use Graphic
Project Tracking Track Sustainability Projects
Project Appears on Chart Energy Use Intensity
Limitations of Normalization Weather regressions are not tunable by meter (as they are in Cost Avoidance) so you can t adjust Balance Point by meter or delete outliers. This results in a considerable number of failed regressions which default to no weather normalization for that meter
Limitations of Normalization No adjustments are made, or can be made, for any other significant variables over time (occupancy, new loads, etc. although EUI charts account for floor area).
Many Calendarized and Normalized Reports