public SolarVsUtilityProjection CalculateFutureProjection(
IYearlyKwhUsage solarEstimate,
ProjectionParameters projectionParameters
)
{
var projection = new List <IYearlyKwhUsageCompare>();
var utilityEstimate = projectionParameters.UtilityYear;
var paidOffSolarEstimate = new YearlyKwhUsageFromAnnual(
0, solarEstimate.TotalKiloWattHours
);
// Each year to project
for (int i = 0; i < projectionParameters.YearsToProject; i++)
{
projection.Add(new YearlyKwhUsageCompare(
FormulaHelpers.CompoundInterest(utilityEstimate.TotalCost, projectionParameters.PercentIncreasePerYear, 1, i),
utilityEstimate.TotalKiloWattHours,
i,
// After financeYears, solar panels are no longer paid for
i < projectionParameters.FinanceYears ?
solarEstimate : paidOffSolarEstimate
));
}
return(new SolarVsUtilityProjection(solarEstimate, projection, projectionParameters.FinanceYears));
}
public void ShouldCalculateCorrectInterest(
double principal,
double interestRate,
int compoundsPerYear,
int timeInYears,
double expectedAmount
)
{
var result = FormulaHelpers.CompoundInterest(principal, interestRate, compoundsPerYear, timeInYears);
Assert.AreEqual(expectedAmount, result, .01);
}
public void ShouldIncreaseProjectionByCorrectAmount(int yearsToProject)
{
var result = _subject.CalculateFutureProjection(
GetSampleData(),
new ProjectionParameters(GetSampleData(), yearsToProject, yearsToProject, PERCENT_INCREASE_PER_YEAR)
);
var sample = GetSampleData();
for (int i = 1; i < yearsToProject; i++)
{
Assert.AreEqual(
FormulaHelpers.CompoundInterest(ORIGINAL_COST, PERCENT_INCREASE_PER_YEAR, 1, i),
result.FutureProjection[i].TotalCost,
.01,
$"{i} index Cost");
}
}