Solar Temperature Loss Calculator

Calculator

Use estimated module temperature (NOCT model) or direct temperature. Enter typical site values for construction planning and feasibility checks.

System size (kW DC at STC)

Nameplate DC size at STC (25°C, 1000 W/m²).

Irradiance (W/m²)

Plane-of-array irradiance; 1000 W/m² equals STC.

Temperature coefficient (%/°C)

Typically negative for PV modules (e.g., -0.40).

Reference temperature (°C)

Usually 25°C for STC comparisons.

Other DC losses (%)

Soiling, wiring, mismatch, and similar losses.

Inverter efficiency (%)

AC conversion efficiency (typical 96–99%).

Peak sun hours (h/day)

Used for a simple daily energy estimate.

Module temperature method

Choose estimate if you do not have module temperature.

Ambient temperature (°C)

Used by NOCT estimation method.

NOCT (°C)

Common range 42–48°C; used for estimation.

Module temperature (°C)

Used only when method is direct input.

Scenario	System (kW)	Irradiance (W/m²)	Ambient (°C)	NOCT (°C)	Coeff (%/°C)	Used temp (°C)	Temp loss (%)	AC power (kW)
Hot day, mid irradiance	10	850	35	45	-0.40	~61.56	~14.63	~6.90
Mild day, high irradiance	10	950	25	45	-0.40	~54.38	~11.75	~7.91
Cool day, direct temperature	10	800	—	—	-0.40	35.00	~4.00	~7.15

Example figures are illustrative and will vary with losses and efficiency assumptions.

Estimated module temperature (NOCT model): T_cell = T_amb + (NOCT − 20)/800 × G
Temperature power factor: f_T = 1 + (γ/100) × (T_cell − T_ref)
Irradiance factor: f_G = G/1000
DC power (before other losses): P_DC = P_STC × f_G × f_T
After other losses: P_DC,net = P_DC × (1 − L/100)
AC power: P_AC = P_DC,net × (η/100)
Temperature loss (%): Loss = (1 − f_T) × 100 (negative implies gain)