The new technology to harness the sun that has achieved the most widespread uses has been PV, solar photovoltaic panels , which exploit a quantum-mechanical effect to directly create usable electricity flows from some wavelengths of solar energy without a single moving part. 196 They have become a common sight on rooftops as generous rebates and tax incentives – and social-status signaling – have caused them to rapidly increase in number. Their cost has gone down significantly in the last decade, leading many people to confidently predict that they will follow something like Moore’s Law and keep getting rapidly cheaper, eventually giving us something like 100% renewable energy. Your authors think PV is very cool and are in favor of it, but that it will not necessarily do everything that most people seem to think it will. Why? Because the sun doesn’t shine at night. There are also clouds in the sky. These are basic realities, and they affect the way power flows from a PV panel, in a predictable way re: night, and semi-unpredictable re: clouds, varying with the climate. But our current culture expects baseload power. That means, PV can either be a fairly small percent of the total power generation, OR extra mechanisms must be built to even out the flow. The usefulness of PV also varies with the season and the latitude: it will be no surprise that places with intense sunlight will find PV more effective than those in high-latitude cloudy locations. Moreover, the idea of transitioning to all solar PV doesn’t take en ergy quality into account. The energy that creates solar panels tends to be concentrated fossil energy. While the energy panels output is slow and erratic. So, we generally wind up with more watts, but they are lower-quality watts; they happen when they happen, rather than when we necessarily want them. In that sense, it’s an “energy quality versus energy quantity trade.” If made wisely, it is probably a good one and is arguably better than spending the fossil energy to make plastic toys.
Here are a few more characteristics of PV:
● If used as the main power source of a society that demands baseload, there would need to be some way of smoothing out the power to deal with intermittence and the hours of darkness. This “storage” would cost a lot more than the PV itself, and there is currently no system that people would find affordable to do this. Then again, when measured against the hidden costs of wrecking the world with CO 2 , the current monetary nature of “affordability” is arguably skewed. Ergo most of the current (recently very cheap) installed costs for solar are for adding it to an existing grid, not as stand-alone systems.
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