Cabling and system losses

In this document

You will learn how to incorporate your installation’s cabling losses into the design and how to configure thermal, auxiliary, degradation, environmental, and unavailability losses.

Cabling and system losses

Cabling losses

Available settings	DC cable losses AC losses after inverter AC losses after inverter transformer

Cabling losses can significantly impact the system’s efficiency. Therefore, they must be included in the calculation for higher simulation accuracy. Their values in the energy system designer are represented in percentages.

You can change the default cabling losses in the Cabling section.

Adjust the default values for different cabling sections as required.
The connection diagram helps you visualize the connections between components with numbered cable types for better identification.

You can examine the impact of cabling loss on overall system performance in the Evaluate Analytic’s PV system summary section.

System losses

You can view and edit other system losses, such as degradation, auxiliary, unavailability, and environmental losses, in the Losses category.

View and adjust any default values as required. Scroll down to reveal further parameters.
The values you have changed will have the “back” button to revert changes to default.

Auxiliary losses

Available settings	Input method Day constant losses From inverter power threshold Day proportional losses From inverter power threshold Night constant losses

Auxiliary losses refer to the energy consumed by auxiliary systems and components in a solar power system that do not contribute to the primary energy output, impacting overall efficiency and performance.

The auxiliary losses can be set in percent or kW. Select the preferred method based on the required inputs.

Auxiliary loss		Description
Day constant losses		Represents fixed energy losses that occur during the day, regardless of the system's output level.
	From inverter power threshold	Refers to energy losses incurred when the inverter operates below the power output threshold, directly related to day constant losses.
Day proportional losses		Indicates energy losses that vary with the system's power output, increasing as the inverter generates more electricity.
	From inverter power threshold	Describes losses associated with inverter performance under varying load conditions during the day, directly linked to day proportional losses.
Night constant losses		Accounts for fixed energy consumption during nighttime when the system is not generating power

Degradation losses

Available settings	Degradation first year Annual degradation

Degradation losses refer to the gradual reduction in solar panel efficiency over time due to various factors, leading to decreased energy output as the materials in the panels wear down.

Degradation loss	Description
Degradation first year	Refers to the initial loss of efficiency that occurs during the first year of a solar panel's operation, primarily due to light-induced degradation (LID).
Annual degradation	Represents the ongoing reduction in solar panel efficiency that occurs each subsequent year after the first, typically at a consistent rate.

Environmental losses

Available settings	Snow losses Soiling losses

Environmental losses refer to the reduction in solar energy output caused by external factors such as snow accumulation and soiling from dust, dirt, or debris on the solar panels, which obstruct sunlight and decrease efficiency.

You can adjust snow and soiling losses per month by clicking the relevant “Edit” link.

Environmental loss	Description
Snow losses	Refers to the reduction in solar energy output caused by accumulated snow covering solar panels, which obstructs sunlight and decreases efficiency.
Soiling losses	This represents the decrease in energy output due to the accumulation of dust, dirt, or debris on solar panels, blocking sunlight from reaching the photovoltaic cells.

Unavailability losses

Available settings	Internal (yearly) External (yearly)

Unavailability losses refer to the reduction in energy output due to periods when the solar power system is not operational, which can be classified into internal losses caused by equipment failures or maintenance and external losses due to factors like grid outages or environmental conditions.

Unavailability loss	Description
Internal (yearly)	Refers to the energy loss due to system downtime caused by internal factors such as equipment failures, maintenance, or operational issues, impacting overall energy production annually.
External (yearly)	Represents the energy loss due to external factors such as grid outages, environmental conditions, or regulatory constraints that lead to periods of unavailability in the solar power system over the course of a year.