PV model add f_cover and PR

[christophwaibel]

add parameter for coverage (e.g. coloured PV) and add performance ratio (set to by default 0.85) to account for system losses (cabling, etc.)

But we keep the nominal operating cell temperature model

https://miro.com/app/board/o9J_leSAuA0=/

[ChrisZenhub]

Changes to Energy Systems Hizard:

• move fields for spec emissions and embodied emissions to the right
• make text fields for spec emissions and embodied emissions the same width as spec cost and capital cost text fields
• change labels from Specific Embodied Emissions to Spec. Emb. Emissions to make it fit
• remove the text label (%) next to Module Efficiency, because it is not in percentage, it is fraction
• add text labels Performance ratio and Surface transmittance beneath Module Efficiency and add two corresponding text fields (only numeric input, max 1.0, min 0.01, default for performance ratio 0.85, default for surface transmittance to 1.0)

Changes to Hive.IO:

• add variables for performance ratio and surface transmittance, similar to the existing variable for module efficiency (follow the same software architecture)
• Hive.IO.EnergySystems.Photovoltaic will need to have a new variable for surface transmittance; it already has one for performance ratio (PR). Call the surface transmittance variable f_cover (consistent with Energie- und Klimasysteme 1 und 2) and as a xml comment, describe it as "Durchlassgrad der Zellabdeckung. Surface transmittance of the cell cover, e.g., for coloured PV".
• the constructor needs to read in f_cover
• extend the time resolved efficiency calculation methods. see below

[ChrisZenhub]

public void SetInputComputeOutput( ...) for (int t = 0; t < horizon; t++) { ... double eta = this.RefEfficiencyElectric * (1 - this.Beta * (tempPV - refTemp)) * this.PR * this.f_cover;

[ChrisZenhub]

public void SetInputComputeOutputSimple( ...) for (int t = 0; t < horizon; t++) { electricityGenerated[t] = meanIrradiance[t] * this.SurfaceArea * this.RefEfficiencyElectric * this.PR / 1000.0 * this.f_cover;