We want to build a photoelectrochemical device by joining a \(BiVO_4\) photoanode and a double junction amorphous silicon solar cell. The J-V curves of both the photoanode and the solar cell are given in the graph.These curves are measured at an irradiance of \(1000W/m^2\). As explained in the video lectures, the solar-to-hydrogen efficiency is given by:\(\eta_{STH}=\frac{J_{photo}*1.23V}{P_0}\)Calculate the solar-to-hydrogen efficiency of the device and give it as a percentage: ______
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The cycle in the figure has been explained during the lectures. It shows the route to convert the hydrogen produced by water splitting into natural gas.The following efficiencies are considered:Based on the above given conversion efficiencies, calculate the efficiency of the complete process in %:Other version of a hydrogen cycle in a hydrogen based economy is to directly store and convert the hydrogen into energy, as in the scheme shown here.The following efficiencies are considered:Calculate the efficiency of the complete process in %:Regarding the calculations you performed, which method will you chose to use the hydrogen produced during electrolysis:
A. Option 1: Use the hydrogen in WGS and FT reactions to obtain \(CH_4\)
B. Option 2: Directly store and use the hydrogen produced
C. Both options are equally good
The cycle in the figure has been explained during the lectures. It shows the route to convert the hydrogen produced by water splitting into natural gas.The following efficiencies are considered:Based on the above given conversion efficiencies, calculate the efficiency of the complete process in %:Other version of a hydrogen cycle in a hydrogen based economy is to directly store and convert the hydrogen into energy, as in the scheme shown here.The following efficiencies are considered:Calculate the efficiency of the complete process in %: ______
The cycle in the figure has been explained during the lectures. It shows the route to convert the hydrogen produced by water splitting into natural gas.The following efficiencies are considered:Based on the above given conversion efficiencies, calculate the efficiency of the complete process in %: ______
The world electricity consumption is roughly \(20300 TWh\) per year. We want to cover the total electricity demand of the world by installing solar thermal power in the Sahara desert, where the average solar insolation is: \(6.3 kWh/m^2day\). Assuming that the overall effciency of a solar thermal power plant is 20%, how much area in \( km^2\) will be needed to cover the world electricity demand?If the area of the Sahara desert is \(9,400,000 km^2\), how much percentage of the Sahara desert area would that cover? ______