andrewducker | (Reply)

From:

Directly using the heat would definitely be more efficient.

Using photovoltaics would be less efficient, but still could be more economical.

A friend recently dissected an old laser-disc player. The laser discs had data on both sides, but only a single laser read-head. A complex and expensive mechanical system would detach the laser from its mounting, lower it down, rotate it, move it sideways, raise it, move it sideways, rotate it, and lower it down. Mechanical parts were far cheaper than the then-expensive laser.

If we still used laser discs today, a modern player would just have two cheap solid-state lasers, one on each side.

Heliotracking mirrors looked like they would be the future of solar. Mirrors were far cheaper than photovoltaic panels, and the savings more than offset the cost and inconvenience of maintaining the mechanical tracking system.

Now that photovoltaic panel prices are dropping to ridiculously low rates, it's likely cheaper to cover more land with inexpensive low-maintenance static PV panels, rather than use more efficient but higher-maintenance mirrors. From the point of view of investors, those PV panels can be generating revenue immediately, while the fuel plant is being fine-tuned. If fuel prices drop and you shut down production, the PV panels can still sell electricity to the grid. If fuel prices rise, you can keep producing fuel at at night using grid power.