7.4.8: Pros and Cons of PV Solar Power Harnessing

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The PV conversion of solar power is much less controversial than the CSP technology. A considerable advantage is that after the installation, a PV system is essentially maintenance free – what is only needed is removing the dust from the glass surfaces of the panels once in a while. The panels occupy some space – but in small household installations the space occupied is a rooftop. And large industrial-scale installations can be located at terrains of low or no value for agriculture.

One drawback of PV facilities is that they cannot deliver power during nighttime hours, as the the CSP plants using the molten salt technology do. Currently existing storage batteries may solve the problem at a single household scale – but industrial-scale PV installations of tens or hundres of MV capacity would need storage batteries capable to deliver a similar power for many hours – such batteries have not yet been developed. But let’s be optimistic, much R&D work with the aim of developing such “monster batteries” is going on, so the problem may be eventually solved.

An argument that can be often heard from people who are adversaries of renewable energy (yes, there are such people – even among the most influential American politicians) is that a payback time of PV panels is very long, even longer than their the average lifetime. The payback time is defined as the time needed for a panel to generate the amount of electric energy equal to the energy that has been used for manufacturing the panel. It’s a demagogic and unfair argument, though – responsible research quoted by this Wikipedia article – see the Energy Payback section – shows that the average payback time for the most widely used silicon crystal PV devices is about 2 years, as compared with the expected average lifetime of about 30 years of such devices.