America's New Calling Stephen R. Foster, J. Thomas Rogers, Robert S. Potter Southwestern University Georgetown, TX Adviser Rick denman The UMAP Journal 30(3)(2009). @Copyright 2009 by COMAP, Inc. All rights reserved
America’s New Calling by Stephen R. Foster, J. Thomas Rogers, Robert S. Potter Southwestern University Georgetown, TX Adviser: Rick Denman The UMAP Journal 30 (3) (2009). ©Copyright 2009 by COMAP, Inc. All rights reserved
Abstract The cell phone revolution warrants an examination of its energy impacts future. Thus, our model adheres to two requirements: it can evaluate e since 1990; and it is flexible enough to predict future energy needs. Mathematically speaking, our model treats households as state machines and uses actual demographic data to guide state transitions. We produce national projections by simu- ting multiple households. Our bottom-up approach remains flexible, allowing us to: 1 model energy consumption for the current United States, 2)determine efficient phone adoption schemes in emerging nations, 3) assess t t of wasteful practices, and 4) predict future energy needs. We show that the exclusive adoption of landlines by an emerging nation would be more than twice as efficient as the exclusive adoption of cell phones. However, we also show that the elemination of certain wasteful practices can make cell phone adoption 175% more efficient at the national level. Furthermore we give two forecasts of the current United States, revealing that a collaboration between cell phone users and manufacturers car result in savings of more than 3.9 billion Barrels of Oil Equivalent over the next 50 years Problem Back ckgroune In the year 1990, less than 3 percent of Americans owned cell phones ITU. Since then,a growing number of households have elected to ditch their landline in favor of acquiring cellular phones for each household member. Our task is to develop a model for analyzing how the cell hone revolution impacts electricity consumption at the national level Such a model ought be able to Assess the energy cost of the cell phone revolution in America Determine an efficient way of introducing phone service to an nation like America. Examine the effects of wasteful cell phone habits Predict future energy needs of a nation(based on multiple growth scenarios. Assumptions The population of the United States is increasing at a rate of roughly 3. 3 million people er year(according to the U.S. Census Bureau The relatively stable energy needs of business landlines, government landlines, payphones etc. have a negligible impact on energy consumption dynamics during the household transition from landlines to cell phones No household member old enough to need phone service is ever without phone service Citizens with more than one cell phone are rare enough to have a negligible energy The energy consumption of the average cell phone re The UMAP Journal 30(3)(2009). @Copyright 2009 by COMAP, Inc. All rights reserved
Abstract The ongoing cell phone revolution warrants an examination of its energy impacts – past, present, and future. Thus, our model adheres to two requirements: it can evaluate energy use since 1990; and it is flexible enough to predict future energy needs. Mathematically speaking, our model treats households as state machines and uses actual demographic data to guide state transitions. We produce national pro jections by simulating multiple households. Our bottom-up approach remains flexible, allowing us to: 1) model energy consumption for the current United States, 2) determine efficient phone adoption schemes in emerging nations, 3) assess the impact of wasteful practices, and 4) predict future energy needs. We show that the exclusive adoption of landlines by an emerging nation would be more than twice as efficient as the exclusive adoption of cell phones. However, we also show that the elemination of certain wasteful practices can make cell phone adoption 175% more efficient at the national level. Furthermore, we give two forecasts of the current United States, revealing that a collaboration between cell phone users and manufacturers can result in savings of more than 3.9 billion Barrels of Oil Equivalent over the next 50 years. Problem Background In the year 1990, less than 3 percent of Americans owned cell phones [ITU]. Since then, a growing number of households have elected to ditch their landline in favor of acquiring cellular phones for each household member. Our task is to develop a model for analyzing how the cell phone revolution impacts electricity consumption at the national level. Such a model ought be able to: • Assess the energy cost of the cell phone revolution in America. • Determine an efficient way of introducing phone service to an nation like America. • Examine the effects of wasteful cell phone habits. • Predict future energy needs of a nation (based on multiple growth scenarios.) Assumptions • The population of the United States is increasing at a rate of roughly 3.3 million people per year (according to the U.S. Census Bureau). • The relatively stable energy needs of business landlines, government landlines, payphones, etc. have a negligible impact on energy consumption dynamics during the household transition from landlines to cell phones. • No household member old enough to need phone service is ever without phone service. • Citizens with more than one cell phone are rare enough to have a negligible energy impact. • The energy consumption of the average cell phone remains constant. The UMAP Journal 30 (3) (2009). ©Copyright 2009 by COMAP, Inc. All rights reserved
We justify the last assumption on the grounds that future changes in cell phone energy require- ments depend largely on changes in user habits and changes in manufacturing efficiency. Thus they are difficult to predict. However, we drop this assumption in our final sectio Energy Consumption Model Our approach involves three steps: We model households as state machines with various phones and appliances We use demographic data to determine the probability of households changing state. By simulating multiple households, we extrapolate national energy impacts Households The ributes: nt of our model is the household. each household has the follo attr m: A number of members old enough to need a telephone. t: A number of landline telephone c: A number of members with cellular phones The state of each household can be described in terms the above values. We will generate m from available demographic data and hold it constant A household can exist in one of four disjoint states at a time. Each state has two associated conditions Initial State-When a household only uses landline telephones 0 Acquisition State- After a household acquires its first cell phone 0<c< Transition State- After all household members have their own cell phone but the landline t>0 The UMAP Journal 30(3)(2009). @Copyright 2009 by COMAP, Inc. All rights reserved
We justify the last assumption on the grounds that future changes in cell phone energy requirements depend largely on changes in user habits and changes in manufacturing efficiency. Thus, they are difficult to predict. However, we drop this assumption in our final section. Energy Consumption Model Our approach involves three steps: • We model households as state machines with various phones and appliances. • We use demographic data to determine the probability of households changing state. • By simulating multiple households, we extrapolate national energy impacts. Households The basic component of our model is the household. Each household has the following attributes: • m : A number of members old enough to need a telephone. • t : A number of landline telephones. • c : A number of members with cellular phones. The state of each household can be described in terms the above values. We will generate m from available demographic data and hold it constant. A household can exist in one of four disjoint states at a time. Each state has two associated conditions. • Initial State - When a household only uses landline telephones. • t > 0 • c = 0 • Acquisition State - After a household acquires its first cell phone. • t > 0 • 0 <c < m • Transition State - After all household members have their own cell phone but the landline is retained. • t > 0 • c = m The UMAP Journal 30 (3) (2009). ©Copyright 2009 by COMAP, Inc. All rights reserved
Final State- After the household abandons their landline telephones t=0 C= These states are disjoint, but we do not assume that all states must be reached during the time. line of a household. We do assume that cell phones, once acquired, are never lost; and we assume that landlines, once dropped, are never readopted. Thus, a household will never reenter a state that it has left. Thus. a household will reach one or more of the above states in the order listed Suppose a household with three members(m=3), one landline telephone (t= 1), and no cell phones yet(c=0). The graph below shows the complete timeline of a hypothetical household with each of the four phases labeled Landline Power Consumption =,-:= 6 °0gss9"s80oa2.4060811214-16-1820 Note that our model will generate household state transition probabilities from available demo- graphic data. However, this process is simulation dependent; and we discuss it later, in the con text of simulating the current United States Nations Households are only part of the story. We model the national timeline during the country-wide transition from landlines to cell phones as a composition of multiple overlapping household time lines. Furthermore, the decisions that households make regarding when to acquire cell phones and when to abandon their landlines are dependent on the larger national context. For example, a household would be much more likely to acquire its second or third cell phone in 2008 than it would have been in 1990 A hypothetical nation with only three households might have the following timeline composi- tion. The UMAP Journal 30(3)(2009). @Copyright 2009 by COMAP, Inc. All rights reserved
• Final State - After the household abandons their landline telephones. • t = 0 • c = m These states are disjoint, but we do not assume that all states must be reached during the timeline of a household. We do assume that cell phones, once acquired, are never lost; and we assume that landlines, once dropped, are never readopted. Thus, a household will never reenter a state that it has left. Thus, a household will reach one or more of the above states in the order listed. Suppose a household with three members (m = 3), one landline telephone (t = 1), and no cell phones yet (c = 0). The graph below shows the complete timeline of a hypothetical household with each of the four phases labeled. 0 2 4 6 8 10 12 14 16 18 90 92 94 96 98 00 02 04 06 08 10 12 14 16 18 20 Power Consumption (watts) Total Power Landline Power Consumption Cell Phone Power Consumption Figure 1. Note that our model will generate household state transition probabilities from available demographic data. However, this process is simulation dependent; and we discuss it later, in the context of simulating the current United States. Nations Households are only part of the story. We model the national timeline during the country-wide transition from landlines to cell phones as a composition of multiple overlapping household timelines. Furthermore, the decisions that households make regarding when to acquire cell phones and when to abandon their landlines are dependent on the larger national context. For example, a household would be much more likely to acquire its second or third cell phone in 2008 than it would have been in 1990. A hypothetical nation with only three households might have the following timeline composition: The UMAP Journal 30 (3) (2009). ©Copyright 2009 by COMAP, Inc. All rights reserved
ouse 2 --a- =4==L= The fact that the three household power usages converge is a result of there being 3 memebers in each of the three randomly selected houses monitored here. For every day, we aggregate the total rate of energy consumption for each household, generating a national timeline like so 9092"9496980002"040608101214161820222426283032"343638‘40 Time We now proceed to construct such a timeline for the current United States. The UMAP Journal 30(3)(2009). @Copyright 2009 by COMAP, Inc. All rights reserved
0 5 10 15 20 25 ’90 ’92 ’94 ’96 ’98 ’00 ’02 ’04 ’06 ’08 ’10 ’12 ’14 ’16 ’18 ’20 ’22 ’24 ’26 ’28 ’30 ’32 ’34 ’36 ’38 ’40 Power Consumption (watts) Time House 1 House 2 House 3 Figure 2. The fact that the three household power usages converge is a result of there being 3 memebers in each of the three randomly selected houses monitored here. For every day, we aggregate the total rate of energy consumption for each household, generating a national timeline like so: 0 10 20 30 40 50 60 ’90 ’92 ’94 ’96 ’98 ’00 ’02 ’04 ’06 ’08 ’10 ’12 ’14 ’16 ’18 ’20 ’22 ’24 ’26 ’28 ’30 ’32 ’34 ’36 ’38 ’40 Power Consumption (watts) Time Total Figure 3. We now proceed to construct such a timeline for the current United States. The UMAP Journal 30 (3) (2009). ©Copyright 2009 by COMAP, Inc. All rights reserved