Presentation on theme: "An introduction to solar cells Hanne Lauritzen, Danish Technological Institute n What is a solar cell? n A brief description of the working principle n."— Presentation transcript:
An introduction to solar cells Hanne Lauritzen, Danish Technological Institute n What is a solar cell? n A brief description of the working principle n Applications n Grid-connected installations n Energy production n Wafer-based solar cells vs. thin film cells n Semitransparent panels
A solar cell is a device that converts light energy to electrical energy
A solar cell is a device that converts light energy to electrical energy...
Rules of thumb: 1 m 2 ~ 100 W p ~ 9 kWh/year Typical one-family house installation: 2-5 kW or 20 – 50 m 2 Pay-back time: years for energy ca. 30 years for investment
Large area South-facing No shadows Tilted
How to evaluate the energy production? Depends on the local weather conditions, the orientation, the temperature, eventual shading ……. energy input energy output T = 25 O C 1000 W/m 2 to be measured Nominal power – energy output under standardized conditions,1000 W/m 2, 25 O C, AM 1.5 – Watt peak, W p Efficiency = Energy output / Energy input 1000 W/m 2 x area
10 % 100 W p 10 % 50 W p 20 % 100 W p The nominal effect W p allows you to compare the energy output from various panels The efficiency allows you to compare the energy output per area - but how do we compare with other energy sources?
How to compare with other energy sources? Price per kWh annual production, cost of installation, expected life time for installation local weather conditions, the orientation, the efficiency of the panel
PRODUCT LIGHTENERGYPRODUCTIONPRICE åbningsgradper panelper areaper energyper area (%)(kWh/year)(kWh/year.m2)(DKK/Wp)(DKK/m2) MSKSi, amorf Si, amorf Schott SolarSi, amorf GSKSi, amorf Würth Solar CIS CIS CIS PhotoSolarSi, amorf Gaia/IdealCombiSi, multi????? REF., ENERGYSi, multi REF., LIGHTSi, multi
Crystalline silicon solar cells made from wafers
”The black diamond” Efficiency: 20 % Efficiency: 0 %
energy input energy output T = 25 O C 1000 W/m 2 x area of cell 0,01 W Efficiency = Energy output / Energy input
Efficiency of unit producing 0.01 W energy, input energy 1000 W/m 2 Area: 10 cm x 10 cm = 100 cm 2 Energy input: 1000 W/m 2 x 100 cm 2 = 0.1 W Efficiency: 0.1 W / 0.01 W = 10 % Area: 100cm 2 – 64 x 0.25 cm 2 = 84 cm 2 Energy input: 1000 W/m 2 x 84 cm 2 = W Efficiency:0.01 W / W = 12 % Efficiency of the unit Efficiency of the active area
CIGS products from Würth Solar - uniform dark grey appearance