Parametrization of the PV system. Required for simulating PVOUT parameter.

required float value (greater than zero). Total installed DC power of the PV system in kilowatts-peak (kWp). The total PV system rating consists of a summation of the panel ratings measured in STC.

optional string formatted as "yyyy-mm-dd" (example 2015-01-01). Start-up date of the PV system (unpacking of modules). This parameter is used for calculation of degradation of modules caused by aging. If omitted, the degradation is not taken into account.

optional, default is 'false'. The parameter affects PV power calculation for 'GeometryFixedOneAngle' geometry, then 'GeometryOneAxisInclinedNS' and 'GeometryOneAxisHorizontalNS' trackers if backTracking="false". When 'selfShading' is switched on, the simulated PV power is typically lower comparing to standalone PV construction not affected by shading from its neighbors. With trackers, always switch off 'backTracking' attribute, because the back tracking avoids self-shading.

Parametrization of the PV system modules. Required for simulating PVOUT parameter. All modules in one PV system are considered of the same type.

required. Enumerated codes for materials used in PV modules. Use 'CSI' for crystalline silicon, 'ASI' for amorphous silicon, 'CDTE' for cadmium telluride, 'CIS' for copper indium selenide. For the estimate of module's surface reflectance we use an approach described here.

Estimated annual degradation [%] of rated output power of PV modules. This element is only considered if "dateStartup" attribute of PV system is present. If the element is missing, degradation defaults to 0.5%/year.

Estimated annual degradation [%] of rated output power of PV modules in the first year of operation. If the element is missing, degradation defaults to 0.8%/year.

Normal operating cell temperature (NOCT). Float value of the temperature in degrees Celsius of a free standing PV module exposed to irradiance of 800 W/m2 in the ambient air temperature of 20°C and wind speed of 1 m/s. The value is given by manufacturer and for ventilated free-standing PV systems only. If the element is missing, the NOCT value defaults to (based on technology):

CSI=46°C
ASI=44°C
CDTE=45°C
CIS=47°C

Negative percent float value representing the change of PV panel output power for temperatures other than 25°C (decrease of output power with raising temperature). This property is given at the STC by manufacturer. If the element is missing, the PmaxCoeff value defaults to (based on technology):

CSI=-0.438%/°C
ASI=-0.18%/°C
CDTE=-0.297%/°C
CIS=-0.36%/°C

Parametrization of the PV system inverter. Required for simulating PVOUT parameter. All inverters in one PV system are considered of the same type.

Efficiency of the inverter. If the element is missing, the efficiency is given as a constant value of 97.5%.

required, based on type:

EfficiencyConstant:

float number, [%]. Value of inverter's efficency known as Euro or CEC (California Energy Commission) efficiency. This value is a calculated weighted efficiency given by manufacturer. It gives a simplified picture about an inverter's, in fact non-linear, performance. Valid range of this value is typically in the range 70%-100%. For better results, it is recommended to provide inverter's efficiency curve.

EfficiencyCurve:

text value, pairs of kW:percent. Efficiency of inverter is of non-linear nature, so it can be described as simplified curve defined as list of data points. Data point on the curve is defined by coordinates, where the x coordinate is absolute float value of input power in kilowatts (kW) and y coordinate is percent float value of the corresponding inverter's efficiency (%). This parameter accepts string value of this pattern: 'x1:y1 x2:y2 x3:y3 xn:yn'. A dot should be used as decimal separator, white space as a pair delimiter and colon as x:y delimiter. We assume the last point determines the maximum input power of the inverter (with corresponding efficiency). Example of an efficiency curve with the maximum input power of 3 kW is:

<pv:efficiency xsi:type="pv:EfficiencyCurve" dataPairs="0:85.6 0.5:96.2 1:98 1.5:97 2:97 2.5:96 3.0:96"/>

It is assumed, that one efficiency curve is valid for all inverters of the PV system (their powers are summed).

Maximum power accepted by the inverter as AC output. Higher power values are 'clipped'. Clipping refers to the situation where the AC power output of an inverter is limited due to the peak rating of the inverter (the parameter value in kW), even though the additional power may still be available from the solar modules. If you have power factor (PF) and AC limit in kVA available, use this formula: PF * AC_limit_kVA = kW, to obtain the value of this parameter.

No default.

Estimation of various PV losses.

Estimation of power losses on the DC side. If the element is missing, the specific DC losses are estimated by default as:

snowPolution: 2.5%

cables: 2.0%

mismatch: 1.0%

Distribution of the 'snowPollution' attribute value into 12 monthly average values. Value of the parameter must consist of 12 percent float values delimited by white space. If this parameter is present, it takes precedence over 'snowPollution' attribute. Example:

<pv:dcLosses cables="0.2" mismatch="0.3" monthlySnowPollution="5 5.2 3 1 1 1 1 1 1 1 2 4"/>

Estimation of power losses on the AC side. If the element is missing, the specific AC losses are estimated by default as:

transformer: 1.0%

cables: 0.5%

The element is for defining PV plant layout on the ground. The reason is to provide inputs for calculation of self-shading impact on PV power (e.g., how close to each other are PV constructions).

required, unitless ratio. The attribute specifies the ratio of distance between the neighboring PV table legs and PV table width. Direction of the distance depends on whether topology is specified as TopologyRow or TopologyColumn.

PROPORTIONAL = 20%
UNPROPORTIONAL_1 = 40%
UNPROPORTIONAL_2 = 60%
UNPROPORTIONAL_3 = 80%
When this attribute is missing, the self-shading influence is estimated to 5%.