Calculate heat output and efficiency of evacuated tube solar collectors for medium-high temperature applications.
Input Parameters
Results
--
Gross Area
m²
--
Heat Output
W
--
Efficiency
%
--
Daily Energy (5hr)
kWh
Note: Evacuated tubes outperform flat plates at high ΔT (>40°C). The vacuum insulation reduces heat losses significantly at elevated temperatures.
Reference
Absorber Area = N x (L/1000) x (D/1000) x 0.85
Efficiency: η = η₀ - a₁(ΔT/G) - a₂(ΔT²/G)
Typical: η₀=0.75, a₁=1.2 W/m²K, a₂=0.005 W/m²K²
Heat Output = Absorber Area x G x η