Annualizing Energy Consumption in Residential Households in the 2015 RECS For JSM July, 2019 | Denver, CO By Jay Olsen, Mathematical Statistician

Residential Energy Consumption Survey (RECS) Last completed in 2015 Collects household characteristics by in-person or online questionnaire These characteristics include information about size of household, equipment in the household, and fuels used Collects energy consumption information from utilities Jay Olsen, JSM Denver, July 2019

The Problem of Calendar Year Consumption Want to measure energy consumption from January 1 through December 31 Utility billing records frequently do NOT begin on the first day of the month At the time of data collection, utility records for January 1 of the previous year may have been archived Utility records may be missing some months Jay Olsen, JSM Denver, July 2019

Illustration – Not the First of the Month This graph is just to give you a visual representation of what a series of utility bills that we receive from an electricity supplier. looks like. This is not real data, but it’s typical of a household that uses electricity for air conditioning and not heating. You can see that it peaks in the summer. You’ll notice that the blue bar for the first bill doesn’t quite line up with January 1st, 2015. And the same with the last bill. Honestly, if this is all we got from utility respondents, we’d be happy with it. If the first bill covers 30 days, and 20 of them are in 2015, we’d just go ahead and prorate that bill. We’d be implicitly assuming that late December 2014 was pretty much the same as early January 2015, but if that was the only assumption we made, we’d live with it. Jay Olsen, JSM Denver, July 2019

Illustration – January of Last Year Archived Calendar Year 2015 Jay Olsen, JSM Denver, July 2019

Illustration – Missing Month Calendar Year 2015 Jay Olsen, JSM Denver, July 2019

The Annualization Process Simple proration would be defensible for “spillage” cases, but not “shiftage” or “donut” cases The process made use of the other information from the RECS survey Household characteristics, weather data from NOAA, and equipment info were used to estimate consumption Jay Olsen, JSM Denver, July 2019

Engineering Estimates A heating estimate for each month was based on heating degree days, the estimated heating load for the household, and equipment efficiency A cooling estimate for each month was based on cooling degree days, the estimated cooling load for the household, and equipment efficiency Other energy consumption for the month was based on the total days and reported appliance usage Jay Olsen, JSM Denver, July 2019

Engineering Estimates A heating estimate for each month was based on heating degree days, the estimated heating load for the household, and equipment efficiency A cooling estimate for each month was based on cooling degree days, the estimated cooling load for the household, and equipment efficiency Other energy consumption for the month was based on the total days and reported appliance usage The sum of these for each month was that month’s engineering estimate Jay Olsen, JSM Denver, July 2019

Engineering Estimates A heating estimate for each month was based on heating degree days, the estimated heating load for the household, and equipment efficiency A cooling estimate for each month was based on cooling degree days, the estimated cooling load for the household, and equipment efficiency Other energy consumption for the month was based on the total days and reported appliance usage The sum of these for each month was that month’s engineering estimate Jay Olsen, JSM Denver, July 2019

Engineering Estimates Heating + cooling + other would ideally equal actual consumption Can calculate proportion between engineering estimate and actual consumption for all reported periods Apply proportion to engineering estimate for missing periods to fill in consumption This proportion is better than simple proration because it incorporates weather Jay Olsen, JSM Denver, July 2019

For more information U.S. Energy Information Administration home page | www.eia.gov RECS | www.eia.gov/consumption/residential/ Jay Olsen, JSM Denver, July 2019