Add 'Discount Initial Year Cashflow' parameter for Excel-style NPV calculation [v3.8.4]

[softwareengineerprogrammer]

Description

This change enables GEOPHIRES to use Excel-style NPV calculation per user feature request as discussed in NREL#344. This is achieved through the addition of a boolean input parameter Discount Initial Year Cashflow (final name/documentation open to discussion/suggestion) with default value = False (existing NPV calculation behavior) and the option to provide value = True to use Excel-style NPV calculation.

The change also includes testing to establish/confirm parity between GEOPHIRES NPV calculation and the NREL manual's NPV calculation convention per NREL#344 (comment): https://github.com/softwareengineerprogrammer/GEOPHIRES/pull/55/files#diff-780d3d576fea7650243d4fdf0272c5ca5ed2d3751cd09fe0cca69fc1a59b21c8R61-R68

Discount Initial Year Cashflow in web interface parameter browser:

Testing & Verification

1. Added unit tests for NPV calculation with and without discounting the initial year, for both regular and extended (add-on) economics: https://github.com/softwareengineerprogrammer/GEOPHIRES/pull/55/files#diff-01c5adc6b171191b928e59a6206cad4a36e9f2cec9c939e60b4819d518e36664R593-R630
2. Added unit tests that establish parity between this method and Excel documentation's NPV example.
3. Manually verified Fervo 400 MWe with Excel-style NPV (Discount Initial Year Cashflow = True)*: confirmed that the GEOPHIRES result NPV value of $4280.71M matches the value when calculated using a spreadsheet software NPV function from the result's revenue profile:

---

TODO:

1. any provided value except false/False e.g. abc is treated as true, should validate that provided values are boolean-y: created tracking issue Arbitrary strings treated as True for boolean parameters NREL/GEOPHIRES-X#362
2. Make description less wordy: b206bb5
3. Integration with AddOn/extended economics NPV: https://github.com/softwareengineerprogrammer/GEOPHIRES/pull/55/files#diff-17dd22bf389685af0db24572703fe3984846f0b3495f937a2bbb0f6aa5964a4dR350-R354
4. IRR cashflow series - should it use the NPV version? - implementing with assumption that it should not for now unless information to the contrary is discovered

---

*Input:

Discount Initial Year Cashflow, True

Reservoir Model, 1
Reservoir Volume Option, 1
Reservoir Density, 2800
Reservoir Depth, 8500 feet, -- https://pangea.stanford.edu/ERE/db/GeoConf/papers/SGW/2024/Fercho.pdf
Reservoir Heat Capacity, 790
Reservoir Thermal Conductivity, 3.05
Reservoir Porosity, 0.0118
Reservoir Impedance, 0.001
Number of Fractures, 149
Fracture Shape, 4
Fracture Height, 2000
Fracture Width, 10000
Fracture Separation, 30
Number of Segments, 1
Gradient 1, 74, -- temperature at 8500 ft: 200 degC (https://pangea.stanford.edu/ERE/db/GeoConf/papers/SGW/2024/Fercho.pdf); 228.89 degC @ 9824 ft (https://doi.org/10.31223/X5VH8C)
Number of Injection Wells, 39
Number of Production Wells, 39
Production Flow Rate per Well, 120, -- peak flow reported in paper
Production Well Diameter, 7
Injection Well Diameter, 7
Well Separation, 365 feet
Injection Temperature, 60 degC
Injection Wellbore Temperature Gain, 3
Plant Outlet Pressure, 1000 psi
Production Wellhead Pressure, 325 psi
Ramey Production Wellbore Model, 1
Utilization Factor, .9
Water Loss Fraction, 0.05
Maximum Drawdown, 1
Ambient Temperature, 10 degC
Surface Temperature, 10 degC
End-Use Option, 1
Plant Lifetime, 20
Power Plant Type, 2
Circulation Pump Efficiency, 0.80
Surface Plant Capital Cost Adjustment Factor, 0.71, -- $1900/kW (peak production)
Exploration Capital Cost, 30
Well Drilling and Completion Capital Cost, 3.84, -- Assume cost continues to decrease from $4.8M/well (https://houston.innovationmap.com/fervo-energy-drilling-utah-project-2667300142.html)
Reservoir Stimulation Capital Cost, 234, -- 78 wells @ $3M/well
Economic Model, 3
Starting Electricity Sale Price, 0.15
Ending Electricity Sale Price, 1.00
Electricity Escalation Rate Per Year, 0.004053223
Electricity Escalation Start Year, 1
Fraction of Investment in Bonds, .5
Combined Income Tax Rate, .3
Gross Revenue Tax Rate, 0
Inflated Bond Interest Rate, .05
Inflated Equity Interest Rate, .08
Inflation Rate, .02
Investment Tax Credit Rate, .3
Inflation Rate During Construction, 0.05
Property Tax Rate, 0
Time steps per year, 10
Maximum Temperature, 500
Well Geometry Configuration, 4
Has Nonvertical Section, True
Multilaterals Cased, True
Number of Multilateral Sections, 3
Nonvertical Length per Multilateral Section, 4700 feet