Residential
Consumption of
Natural Gas and
Electricity
Power Smart Evaluation
BC Hydro
December 5, 2008
Overview
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Background & Introduction
Data
Model
Results
Concluding Remarks/Suggestions
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Background
• Gas billing data from an earlier Project was available to
compare natural gas and electricity consumption for
calendar year 2006;
• Power Smart Evaluation was asked to look at
residential gas and electricity consumption on the basis
of this information.
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Introduction
• Electricity and Natural Gas compete in the domain of
space, water and supplementary heating;
• Each is affected by changes in the availability, price
and end-use technology of the other.
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Data
• The base data consisted of 1,971 BC households for whom
2006 electricity and natural gas billing information was
available.
• Cross-sectional data was linked from a 2006 residential enduse survey.
• Adjustments were made to ensure proportionate representation
of each region.
• Households were restricted to single family dwellings.
• Single family dwellings with primary natural gas heating have
similar distinguishing characteristics to those using electricity
(comparability).
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Question
How do we use this data to compare Natural Gas and
Electricity in terms of energy expenditure and
(ultimately) cost?
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Answer
We want a mechanism that allows us to compare Gas
and Electricity consumption in a single format.
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A Possible Model
• One approach is to use 2 dependent variables: (1)
Annual Electricity Consumption and (2) Annual Natural
Gas Consumption
• Next add the usual independent variables for each
dependent one: (1) Space Heat (Gas/Electric) (2) Hot
Water (Gas/Electric) (3) Supplemental Space Heat
(Electric/None)
• Then include Intercepts for both (representing a base
load)
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Equations (Functional Form)
Electric = Intercept + Space Heat + Water Heat +
Supplemental Heat + Region
Gas = Intercept + Space Heat + Water Heat +
Supplemental Heat + Region
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Why this Form?
We can compare Gas and Electricity consumption at
the same time.
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Results I – Model Output
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Conversions and Other Assumptions
Conversions
• Use 277.78 Kwh = 1 Gj
• Assume 1 Gj (Electricity)
≈ $19.15
• Assume 1Gj (Natural Gas) ≈ $15.04
(based on April 2008 BC electricity and natural gas
residential rates including monthly or daily charges)
Power Smart Evaluation
Results I – Sampled Consumption
Source
Natural Gas (Gj) Electricity (Gj) Differential (Gj)
Space Heat
63.4
27.0
-36.4
Water Heat
30.3
10.9
-19.4
Supplemental Heat
14.0
11.5
-3.5
107.7
49.4
-59.3
Total
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Results II – Sampled Cost
Source
Natural Gas Electricity Differential
Space Heat
$954
$516
(438)
Water Heat
$455
$210
(245)
Supplemental Heat
$210
$221
11
$1,619
$947
(672)
Total
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Summary
• Multivariate models compare customer consumption of
one or more fuels.
• Trade-offs between energy alternatives should become
more transparent.
• Energy policy is informed along multiple dimensions.
Power Smart Evaluation
Questions?
mark.rebman@bchydro.com
BC Hydro Power Smart Evaluation
Burnaby BC Canada
Power Smart Evaluation