Present Value of PhotoVoltaics (PV2) is an app that allows homeowners to determine a complete cost of ownership for residential rooftop solar PV systems.
List of minor changes to text language and formatting by page:
Home Page
Typo - change "contact" to "contract"
Replace "ASTM" with "American Society for Testing and Materials (ASTM)"
Address
Analysis Assumptions
Move text out of the initial initial paragraph and then add before each input"
Remove "The real discount rate is calculated using the nominal discount rate and inflation rate. A common nominal discount rate value is either a homeowner's mortgage interest rate or the expected average return on investing in the stock/bond market."
Before Study period add the following text: Heading - "Study Period (Analysis Timeframe)"
"The study period is the timeframe over which you are completing the analysis. The recommended study period is the expected life of solar photovoltaic system because it will account for all costs of owning and operating the system. The default value is set to 25 years because that is a common warranty period for solar panels."
Before the user decides whether to use the default discount and inflation rates, add text that is expanded if clicked on:
Heading: Explanation of Time Value of Money and Discount Rates
"An important factor in evaluating the cost-effectiveness of a long-lived asset (10+ years), such as a solar photovoltaic system, is the time value of money. Time value of money means that a dollar received or paid today (present value) is worth more than a dollar received or paid in the future (future value).
To combine costs that occur at different times, all the costs must be discounted to its value in today's (present) value. The discount rate that is used to calculate this present value can be thought of as the return on investment or cost of borrowing that makes you indifferent to receiving or paying the present value now or the future value later.
For example, if you are indifferent to receiving $0.90 now or $1.00 in 1 year, then your discount rate is 10% because you are willing to receive 10% less now than wait 1 year.
A discount rate can either be in real or nominal terms. A nominal discount rate includes general inflation while a real discount rate excludes general inflation. General inflation is the rate of increase in all prices over time. These three values are necessary to complete the economic analysis. Additional explanation of these three terms is provided for each input below as well as in the User Guide.
"
Add a question with toggle: "Do you want to modify the default discount rate and inflation rate? If yes, then show the 3 inputs.
Should we make the following text expandable?
Before nominal discount rate, add text: Heading - What is the Nominal Discount Rate? "A nominal discount rate is the discount rate including general inflation, and is likely to be easier for a user to be aware. A common nominal discount rate value is either a homeowner's mortgage interest rate (3 % - 6 % on 30-year) or the expected average return on investing in the stock market (average of 8 % to 12 %) or bond market (currently 3% on 30-year treasury). These are "nominal" because it is the rate earned or paid including general inflation of overall prices."
Before inflation rate, add text: Heading - What is the Inflation Rate? "Inflation rate is the long-run general rate of inflation in the economy. The Federal Reserve has a long-run general inflation target of 2 %. Historically, inflation has been below this target with the exception of 2021 and 2022 with much higher rates (7 % +). Expectations are that inflation will decrease in the future back towards, but slightly higher than the 2 % target."
Move real discount rate to after inflation rate (makes more sense to the reader).
Before real discount rate, at text: Heading - What is the Real Discount Rate? "The real discount rate is the discount rate excluding general rate of inflation. Unless the user directly provides it, [PV]^2 calculates the real discount rate using the nominal discount rate and inflation rate."
Electrical Rate
change title in header to Electricity Costs
Change title on the page to Electricity Cost Information
Change Annual Consumption to Annual Electricity Consumption
Add limit to "Average Electricity Price" to not be higher than $1.00/kWh
Add limit to "Electricity Unit Price" to not be higher than $1.00/kWh
Add limit to "Excess Generation / FiT Unit Price" to not be higher than $1.00/kWh
For these 3 changes above the error/warning should state: "Price set unexpectedly high. Ensure your price is in $/kWh."
Change units on PV Grid Connection Rate - Annual to $/kW (NOT kWh)
Under Advanced, change Consumption Escalation Rates to Electricity Price Escalation Rates (Consumption) and change Production Escalation Rates to Electricity Price Escalation Rates (Production)
Solar PV System
add info icon explaining what this is
"System Description is the phrase used to describe the system being analyzed, and will be provided at the beginning of the results report. This phrase will help to differentiate between reports created for different systems."
System Size - limit to be greater than 1000 Watts. Warning should state: "System unexpectedly small. Check if you inputted your system in kW instead of W."
Limit Rated Efficiency of Solar Panels to >10% and <40%. Warning should state: "Efficiency is unrealistic. Check to see if you inputted efficiency in decimal form instead of percent."
Solar PV Costs
Total Installation Costs - Change information icon text to: "Total (gross) costs of installing the system before financial incentives, such as federal tax credits and state/local grants or rebates. User should INCLUDE any up-front utility connection fee. User should EXCLUDE any costs for re-roofing."
Under PPA/Lease Option, change all "PPA" with "PPA/Lease"
SREC
Add text to end of initial paragraph: "For additional information about potential SREC values in your state, go to https://www.srectrade.com/markets/rps/srec/."
In the selection drop down, change the heading from "SREC Payments" to "SREC Payment Type"
For the information icon, add this text at the end:
"States where SRECs may have value (as of August 2022):
Delaware, District of Columbia, Illinois, Indiana, Kentucky, Maryland, Massachusetts, Michigan, New Jersey, Ohio, Pennsylvania, Virginia.
Information on Solar Markets is available here: https://www.srectrade.com/markets/rps/srec/"
Results Page
All values should be right aligned
Make sure there is a space between value and units, including %, yr, etc.
Spell out year.
Remove decimal places. Round to whole numbers except %s.
System Summary - System Size - add comma for number of watts
Information icon for carbon footprint: add the following sentence before "See user guide..." - "The carbon footprint from grid-based electricity is based on the average emissions for that region of the US."
Combine graphs to a single graph like done in the PDF report.
List of minor changes to text language and formatting by page:
Home Page Typo - change "contact" to "contract" Replace "ASTM" with "American Society for Testing and Materials (ASTM)"
Address
Analysis Assumptions Move text out of the initial initial paragraph and then add before each input" Remove "The real discount rate is calculated using the nominal discount rate and inflation rate. A common nominal discount rate value is either a homeowner's mortgage interest rate or the expected average return on investing in the stock/bond market."
Before Study period add the following text: Heading - "Study Period (Analysis Timeframe)" "The study period is the timeframe over which you are completing the analysis. The recommended study period is the expected life of solar photovoltaic system because it will account for all costs of owning and operating the system. The default value is set to 25 years because that is a common warranty period for solar panels."
Before the user decides whether to use the default discount and inflation rates, add text that is expanded if clicked on: Heading: Explanation of Time Value of Money and Discount Rates "An important factor in evaluating the cost-effectiveness of a long-lived asset (10+ years), such as a solar photovoltaic system, is the time value of money. Time value of money means that a dollar received or paid today (present value) is worth more than a dollar received or paid in the future (future value). To combine costs that occur at different times, all the costs must be discounted to its value in today's (present) value. The discount rate that is used to calculate this present value can be thought of as the return on investment or cost of borrowing that makes you indifferent to receiving or paying the present value now or the future value later. For example, if you are indifferent to receiving $0.90 now or $1.00 in 1 year, then your discount rate is 10% because you are willing to receive 10% less now than wait 1 year. A discount rate can either be in real or nominal terms. A nominal discount rate includes general inflation while a real discount rate excludes general inflation. General inflation is the rate of increase in all prices over time. These three values are necessary to complete the economic analysis. Additional explanation of these three terms is provided for each input below as well as in the User Guide. "
Add a question with toggle: "Do you want to modify the default discount rate and inflation rate? If yes, then show the 3 inputs. Should we make the following text expandable? Before nominal discount rate, add text: Heading - What is the Nominal Discount Rate? "A nominal discount rate is the discount rate including general inflation, and is likely to be easier for a user to be aware. A common nominal discount rate value is either a homeowner's mortgage interest rate (3 % - 6 % on 30-year) or the expected average return on investing in the stock market (average of 8 % to 12 %) or bond market (currently 3% on 30-year treasury). These are "nominal" because it is the rate earned or paid including general inflation of overall prices."
Before inflation rate, add text: Heading - What is the Inflation Rate? "Inflation rate is the long-run general rate of inflation in the economy. The Federal Reserve has a long-run general inflation target of 2 %. Historically, inflation has been below this target with the exception of 2021 and 2022 with much higher rates (7 % +). Expectations are that inflation will decrease in the future back towards, but slightly higher than the 2 % target."
Move real discount rate to after inflation rate (makes more sense to the reader). Before real discount rate, at text: Heading - What is the Real Discount Rate? "The real discount rate is the discount rate excluding general rate of inflation. Unless the user directly provides it, [PV]^2 calculates the real discount rate using the nominal discount rate and inflation rate."
Electrical Rate change title in header to Electricity Costs Change title on the page to Electricity Cost Information Change Annual Consumption to Annual Electricity Consumption Add limit to "Average Electricity Price" to not be higher than $1.00/kWh Add limit to "Electricity Unit Price" to not be higher than $1.00/kWh Add limit to "Excess Generation / FiT Unit Price" to not be higher than $1.00/kWh For these 3 changes above the error/warning should state: "Price set unexpectedly high. Ensure your price is in $/kWh." Change units on PV Grid Connection Rate - Annual to $/kW (NOT kWh) Under Advanced, change Consumption Escalation Rates to Electricity Price Escalation Rates (Consumption) and change Production Escalation Rates to Electricity Price Escalation Rates (Production)
Solar PV System add info icon explaining what this is "System Description is the phrase used to describe the system being analyzed, and will be provided at the beginning of the results report. This phrase will help to differentiate between reports created for different systems." System Size - limit to be greater than 1000 Watts. Warning should state: "System unexpectedly small. Check if you inputted your system in kW instead of W." Limit Rated Efficiency of Solar Panels to >10% and <40%. Warning should state: "Efficiency is unrealistic. Check to see if you inputted efficiency in decimal form instead of percent."
Solar PV Costs Total Installation Costs - Change information icon text to: "Total (gross) costs of installing the system before financial incentives, such as federal tax credits and state/local grants or rebates. User should INCLUDE any up-front utility connection fee. User should EXCLUDE any costs for re-roofing." Under PPA/Lease Option, change all "PPA" with "PPA/Lease"
SREC Add text to end of initial paragraph: "For additional information about potential SREC values in your state, go to https://www.srectrade.com/markets/rps/srec/." In the selection drop down, change the heading from "SREC Payments" to "SREC Payment Type" For the information icon, add this text at the end: "States where SRECs may have value (as of August 2022): Delaware, District of Columbia, Illinois, Indiana, Kentucky, Maryland, Massachusetts, Michigan, New Jersey, Ohio, Pennsylvania, Virginia. Information on Solar Markets is available here: https://www.srectrade.com/markets/rps/srec/"
Results Page All values should be right aligned Make sure there is a space between value and units, including %, yr, etc. Spell out year. Remove decimal places. Round to whole numbers except %s. System Summary - System Size - add comma for number of watts Information icon for carbon footprint: add the following sentence before "See user guide..." - "The carbon footprint from grid-based electricity is based on the average emissions for that region of the US." Combine graphs to a single graph like done in the PDF report.