{ From user Lonnie, Model Solar_panel_analysis at 3-Mar-2015 10:12:49 PM, encoding="UTF-8" }
SoftwareVersion 4.6.0


{ System Variables with non-default values: }
Time := 2015..2044
TypeChecking := 1
Checking := 1
ShowHier := 1
SaveOptions := 2
SaveValues := 0
{!40000|ShowDescriptionMarks := 1}
{!40000|Att_CatLineStyle Graph_Primary_Valdim: 1}




Model Solar_panel_analysis
Title: Solar panel analysis
Description: Would it be cost effective to install a solar PV system on the roof of my house?~
~
This model was build during <a href="http://AnalyticaOnline.com/Videos/SolarPanels/SolarPanels.html">an introductory video on building a complete model</a>.
Author: Lonnie Chrisman, Ph.D.~
Lumina Decision Systems
Date: Sat, Feb 28, 2015 2:27 PM
SaveAuthor: Lonnie
SaveDate: Tue, Mar 3, 2015 10:12 PM
DiagState: 2,1,0,786,416,17
FontStyle: Arial,15
FileInfo: 0,Model Solar_panel_analysis,2,2,0,0,C:\Users\Lonnie\Documents\Camtasia Studio\Solar Panel Analysis\Solar Panel Video model.ana

Module Utility_bills
Title: Utility bills
Description: Examines my electricity consumption and how my utility bills are computed.
Author: Lonnie
Date: Tue, Mar 3, 2015 10:00 PM
NodeLocation: 112,80,1
NodeSize: 48,24
DiagState: 2,365,-2,960,538,17

Variable Energy_consumption
Title: Energy consumption
Units: kWh / month
Description: Monthly electrical energy used by my household.~
This represents a typical month in the future.
Definition: Table(Month)(450,408,430,473,522,573,566,487,537,481,514,683)
NodeLocation: 88,136,1
NodeSize: 56,24
Aliases: FormNode Energy_con1425271768

Variable Tier_rate
Title: Tier rate
Units: $ / kWh
Description: The price charged per kWh by my utility company.
Definition: Table(Tier)(0.1617,0.18491,0.27322,0.33322)
NodeLocation: 528,48,1
NodeSize: 48,24

Variable Energy_cost
Title: Energy cost
Units: $ / month
Description: The price paid for electricity on my monthly utility bill.
Definition: Sum( Tier_usage * Tier_rate, Tier ) * (1 + Users__tax_rate )
NodeLocation: 528,136,1
NodeSize: 48,24
ValueState: 2,280,283,416,303,1,MIDM
Aliases: Alias Energy_cos1425270902

Variable Net_energy_usage
Title: Net energy usage
Units: kWh / month
Description: The net energy that has to be purchased from the utility company each month.
Definition: Energy_consumption - Energy_produced
NodeLocation: 248,136,1
NodeSize: 56,24

Index Tier
Title: Tier
Description: This index defines the Tiers used by PG&E when computing my electricity bill.
Definition: ['Tier 1','Tier 2','Tier 3','Tier 4']
NodeLocation: 88,48,1
NodeSize: 48,24
{!40000|Att_PrevIndexValue: ['Tier 1','Tier 2','Tier 3','Tier 4']}

Variable Tier_allowance
Title: Tier allowance
Units: %
Description: The percentage of my baseline allowance that can be in each tier.
Definition: Table(Tier)(1,0.3,0.7,INF)
NodeLocation: 248,48,1
NodeSize: 48,24
NumberFormat: 2,%,4,2,0,0,4,0,$,0,"ABBREV",0,,,0,0
DisplayOutputs: Variable Tier_usage

Variable Baseline_allowance
Title: Baseline allowance
Units: kWh
Description: The baseline energy allowance assigned to my household by PG&E. This is the maximum amount of energy that can be covered by tier 1 each month.
Definition: 327
NodeLocation: 400,48,1
NodeSize: 48,24

Variable Tier_usage
Title: Tier usage
Units: kWh / month
Description: How many kWh are dispatched to each tier level. 
Definition: Dispatch ( Net_energy_usage, Tier_allowance * Baseline_allowance, Tier )
NodeLocation: 400,184,1
NodeSize: 48,24
WindState: 2,102,83,683,224
ValueState: 2,248,251,416,303,0,MIDM
Att__TotalsIndex: [Tier]

Variable Users__tax_rate
Title: Users' tax rate
Units: %
Description: The city of San Jose imposes a 5% tax on each dollar of electricity used.
Definition: 5%
NodeLocation: 528,232,1
NodeSize: 48,24
WindState: 2,102,83,472,224

Alias Energy_pro1425262832
Title: Energy produced
Definition: 1
NodeLocation: 88,216,1
NodeSize: 48,24
Original: Energy_produced

Close Utility_bills

Module Solar_panel_output
Title: Solar panel output
Description: Examines how much energy the solar panels will generate.
Author: Lonnie
Date: Tue, Mar 3, 2015 10:00 PM
NodeLocation: 112,160,1
NodeSize: 48,32
DiagState: 2,231,193,730,254,17

Variable Energy_produced
Title: Energy produced
Units: kWh / month
Description: The energy produced by the solar panels, in AC kWh as measured by savings at the meter.
Definition: System_size / 1000 * Monthly_kW_per_kW_pa
IndexVals: ['item 1']
NodeLocation: 224,128,1
NodeSize: 48,24
Aliases: Alias Energy_pro1425262832, Alias Energy_pro1425270924

Decision System_size
Title: System size
Units: dc Watts
Description: The size of the solar panel system installed on my roof, measured in maximum dc Watt capacity.
Definition: Choice(Self,0)
NodeLocation: 72,128,1
NodeSize: 48,24
Aliases: Alias System_siz1425271998, FormNode System_siz1425271755
Domain: [250,500,750,1000,1250,1500,1750,2000]
{!40300|DomainExpr: 250 * (1..8)}
{!40200|Att_ChoiceIndexes: Keyword Self}

Index Month
Title: Month
Description: The months of the year.
Definition: ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec']
NodeLocation: 72,56,1
NodeSize: 48,24
{!40000|Att_PrevIndexValue: ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec']}

Variable Monthly_kW_per_kW_pa
Title: Monthly kW per kW panel
Units: kWh
Description: The kWh that can be expected to be product by a 1kW solar panel system in my area of San Jose.~
~
This data was obtained from pcwatts.nrel.gov
Definition: Table(Month)(79.39701843,85.47025299000001,94.50509644,152.3583374,174.6637878,179.9584656,179.8565216,169.4250946,148.171463,122.2826767,91.23784637,80.16781616)
NodeLocation: 224,56,1
NodeSize: 48,32

Close Solar_panel_output

Module Savings
Title: Savings
Description: Examines the savings on electricity bills that may result from installing a solar panel system.
Author: Lonnie
Date: Tue, Mar 3, 2015 10:00 PM
NodeLocation: 280,120,1
NodeSize: 48,24
DiagState: 2,204,28,960,510,17

Alias Energy_cos1425270902
Title: Energy cost
Definition: 1
NodeLocation: 96,48,1
NodeSize: 48,24
Original: Energy_cost

Alias Energy_pro1425270924
Title: Energy produced
Definition: 1
NodeLocation: 96,120,1
NodeSize: 48,24
Original: Energy_produced

Variable Baseline_cost
Title: Baseline cost
Units: $ / Month
Description: The cost per month of electricity in the absense of solar panels.
Definition: Whatif( Energy_cost, Energy_produced, 0)
NodeLocation: 240,48,1
NodeSize: 48,24

Variable Cost_savings
Title: Cost savings
Units: $ / Month
Description: The monthly savings on my electricity bill that is expected from installing solar panels.
Definition: Baseline_cost - Energy_cost
NodeLocation: 240,120,1
NodeSize: 48,24

Variable Annual_savings
Title: Annual savings
Units: $ / year
Description: The estimated annual savings on my electrical bill that would result from installing solar panels.
Definition: Sum( Cost_savings, Month ) - Annual_expenses
NodeLocation: 400,120,1
NodeSize: 48,24
ValueState: 2,312,315,416,303,0,MIDM
Aliases: Alias Annual_sav1425275225, Alias Annual_sav1425409318, FormNode Annual_sav1425271745

Alias Net_cost_o1425313445
Title: Net cost of system
Definition: 1
NodeLocation: 96,192,1
NodeSize: 48,24
Original: Net_cost_of_system

Variable Insurance
Title: Insurance
Units: $ / yr
Description: The increase in my home owners insurance policy that I expected to result after adding the solar panel system to my insurance policy. 
Definition: 0.3% * Net_cost_of_system
NodeLocation: 240,192,1
NodeSize: 48,24

Variable Annual_maintenance
Title: Annual maintenance
Units: $ / yr
Description: Typical annual cost to maintain the solar panels after they are installed. This might include anything from cleaning the panels to repairing inverters that fail.
Definition: 30 + 2% * Net_cost_of_system
NodeLocation: 240,256,1
NodeSize: 56,24

Variable Increased_property_t
Title: Increased property tax
Units: $ / Yr
Description: The annual increase in property taxes that I expect will result from improving my property by adding a solar panel system.
Definition: 1.25% * Net_cost_of_system
NodeLocation: 240,320,1
NodeSize: 48,32

Variable Annual_expenses
Title: Annual expenses
Units: $ / Yr
Description: The total annual expenses that will be added as a result of installing a solar panel system on my roof.
Definition: Insurance + Annual_maintenance + Increased_property_t
NodeLocation: 400,256,1
NodeSize: 48,24

Alias Net_cost_o1425408734
Title: Net cost of system
Definition: 1
NodeLocation: 96,48,1
NodeSize: 48,24
Original: Net_cost_of_system

Alias Net_cost_o1425408947
Title: Net cost of system
Definition: 1
NodeLocation: 96,48,1
NodeSize: 48,24
Original: Net_cost_of_system

Close Savings

Module Installation_costs
Title: Installation costs
Description: The costs to install a solar PV system.
Author: Lonnie
Date: Tue, Mar 3, 2015 10:00 PM
NodeLocation: 112,256,1
NodeSize: 56,24
DiagState: 2,87,14,960,538,17

Alias System_siz1425271998
Title: System size
Definition: 1
NodeLocation: 96,48,1
NodeSize: 48,24
Original: System_size

Variable Panel_cost_per_dcW
Title: Panel cost per dcW
Units: $/dcW
Description: The estimated cost of solar panels, measured in dcW.~
~
The initial estimate of $3.30/dcW came from <a href="http://pcwatts.nrel.gov">pcwatts.nrel.gov</a>, but I've augmented this with a projection that prices will continue to fall rapidly going into the future.
Definition: 3.30 * (1 - Rate_of_panel_price_)^(Installation_year-2015)
NodeLocation: 96,136,1
NodeSize: 48,24
WindState: 2,102,83,649,224

Variable Panel_and_inverter_c
Title: Panel and inverter cost
Units: $
Description: The net cost of the solar panels and inverters, and any part of the installation cost that scales with the dc watt capacity of the installed system.
Definition: System_size * Panel_cost_per_dcW
NodeLocation: 240,136,1
NodeSize: 48,32

Variable Fixed_cost
Title: Fixed cost
Units: $
Description: Installation costs that don't depend on the number of panels. For example, city permits, connecting the panels to the breaker box, etc.
Definition: 1000
NodeLocation: 240,240,1
NodeSize: 48,24

Variable Cost_of_system
Title: Cost of system
Units: $
Description: The total installation cost of the solar panel system, before any tax credits are applied.
Definition: Panel_and_inverter_c + Fixed_cost
NodeLocation: 392,192,1
NodeSize: 48,24

Variable Tax_credits
Title: Tax credits
Units: $
Description: Tax credits that can be claimed for the installation of the solar panels.
Definition: If Installation_year<=2016 then ~
	30% * Cost_of_system~
else ~
	0
NodeLocation: 392,272,1
NodeSize: 48,24

Variable Net_cost_of_system
Title: Net cost of system
Units: $
Description: This module computes metrics that provide ways of comparing the value of cash flow (or savings flow) over time.
Definition: Cost_of_system - Tax_credits
NodeLocation: 536,224,1
NodeSize: 48,24
ValueState: 2,296,299,416,303,0,MIDM
Aliases: Alias Net_cost_o1425313445, Alias Net_cost_o1425408734, Alias Net_cost_o1425408947, Alias Net_cost_o1425412493, FormNode Net_cost_o1425408935

Variable Rate_of_panel_price_
Title: Rate of panel price decrease
Units: % / year
Description: The rate at which the price of PV solar panels are projected to fall each year going forward.
Definition: 10%
NodeLocation: 96,288,1
NodeSize: 56,32

Alias Installati1425417745
Title: Installation year
Definition: 1
NodeLocation: 240,328,1
NodeSize: 48,24
Original: Installation_year

Close Installation_costs

Module Metrics
Title: Metrics
Description: The metrics computed in this module help you compare the value of savings, or of expenses, that occur at difference points in time.~
~
All metrics use a convention of using 2015 US$.
Author: Lonnie
Date: Tue, Mar 3, 2015 10:00 PM
NodeLocation: 280,256,1
NodeSize: 48,24
DiagState: 2,400,64,960,511,17

Alias Annual_sav1425275225
Title: Annual savings
Definition: 1
NodeLocation: 96,48,1
NodeSize: 48,24
Original: Annual_savings

Alias Annual_sav1425409318
Title: Annual savings
Definition: 1
NodeLocation: 96,48,1
NodeSize: 48,24
Original: Annual_savings

Alias Net_cost_o1425412493
Title: Net cost of system
Definition: 1
NodeLocation: 96,136,1
NodeSize: 48,24
Original: Net_cost_of_system

Variable Annual_savings_flow
Title: Annual savings flow
Units: $
Description: The savings realized each year, expressed in 2015 US$. A negative value means an expense in that year.
Definition: if Time<Installation_year then 0 ~
else if Time=Installation_year then Annual_savings - Net_cost_of_system~
else Annual_savings
NodeLocation: 232,96,1
NodeSize: 48,32
ValueState: 2,152,155,620,415,0,MIDM

Decision Installation_year
Title: Installation year
Description: Select the year in which the installation will take place.
Definition: Choice(Self,1)
NodeLocation: 96,224,1
NodeSize: 48,24
WindState: 2,102,83,491,472
Aliases: Alias Installati1425417745, FormNode Installati1425419775
Domain: Time
{!40300|DomainExpr: Time}
{!40200|Att_ChoiceIndexes: Keyword Self}

Variable Discount_rate
Title: Discount rate
Description: A dollar today is worth more to me than a dollar next year. For example, I can invest it this year and have more than a dollar next year, or I can derinve enjoyment from spending it this year. Discount rate quantifies this time-value of money.~
~
The discount rate here should be inflation adjusted, since we are working with 2015 US$.  For example -- if you have a sure thing 7% investment opportunity, but inflation is 3%, and this is your only consideration, then use 4% as the discount rate.
Definition: 4%
NodeLocation: 96,312,1
NodeSize: 48,24

Objective Net_present_value
Title: Net present value
Units: $
Description: You can think of this metric as being the total savings accumulated across all years, minus the cost of the system, with the caveat that each amount is discounted based on when it occurs. Amounts this year are added directly, whereas amounts next year are discounted, and amounts the year after are discounted again. The result is that more immediate cash flow is weighted more heavily.~
~
Net present value is a pretty good indicator of the value of doing the project. A positive NPV indicates that it is cost effective.
Definition: NPV( Discount_rate, Annual_savings_flow, Time )
NodeLocation: 232,256,1
NodeSize: 48,32
ValueState: 2,338,70,416,303,1,MIDM
Aliases: FormNode Net_presen1425419722

Objective Internal_rate_of_ret
Title: Internal rate of return
Units: %
Description: This is a metric that tells you what the effective compound interest rate that I would receive from the project is.
Definition: Irr( Annual_savings_flow, Time )
NodeLocation: 376,96,1
NodeSize: 48,32
ValueState: 2,307,117,416,303,1,MIDM
Aliases: FormNode Internal_r1425419722
NumberFormat: 2,%,4,2,0,0,4,0,$,0,"ABBREV",0,,,0,0

Objective Time_to_recoup_cost
Title: Time to recoup cost
Units: Years
Description: How many years does it takes to earn back the initial cost of the project from the savings on utility bills? Here the calculation is done without discounting. 
Definition: CondMin( Time, Time >= Installation_year And Cumulate( Annual_savings_flow, Time ) >= 0, Time ) - Installation_year
NodeLocation: 376,256,1
NodeSize: 48,32
WindState: 2,102,83,717,224
ValueState: 2,280,283,416,303,0,MIDM
Aliases: FormNode Time_to_re1425419722

Close Metrics

FormNode Annual_sav1425271745
Title: Annual savings
Definition: 1
NodeLocation: 568,152,1
NodeSize: 184,16
NodeInfo: 1,,,,,,0,72,,,
Original: Annual_savings

FormNode System_siz1425271755
Title: System size
Definition: 0
NodeLocation: 568,32,1
NodeSize: 184,16
NodeInfo: 1,,,,,,0,78,,,,
Original: System_size

FormNode Energy_con1425271768
Title: Energy consumption
Definition: 0
NodeLocation: 568,112,1
NodeSize: 184,16
NodeInfo: 1,,,,,,0,78,,,,
Original: Energy_consumption

FormNode Net_cost_o1425408935
Title: Net cost of system
Definition: 1
NodeLocation: 568,192,1
NodeSize: 184,16
NodeInfo: 1,,,,,,0,72,,,
Original: Net_cost_of_system

FormNode Net_presen1425419722
Title: Net present value
Definition: 1
NodeLocation: 568,232,1
NodeSize: 184,16
NodeInfo: 1,,,,,,0,72,,,
Original: Net_present_value

FormNode Internal_r1425419722
Title: Internal rate of return
Definition: 1
NodeLocation: 568,272,1
NodeSize: 184,16
NodeInfo: 1,,,,,,0,72,,,
Original: Internal_rate_of_ret

FormNode Time_to_re1425419722
Title: Time to recoup cost
Definition: 1
NodeLocation: 568,312,1
NodeSize: 184,16
NodeInfo: 1,,,,,,0,72,,,
Original: Time_to_recoup_cost

FormNode Installati1425419775
Title: Installation year
Definition: 0
NodeLocation: 568,72,1
NodeSize: 184,16
NodeInfo: 1,,,,,,0,78,,,,
Original: Installation_year

Close Solar_panel_analysis