Sheer number of solar advancements suggests that cheap solar electricity is coming soon
Concentrating solar power is a well-known approach to lowering the cost of solar electricity. You focus sunlight from a large area onto a small one, the same way a magnifying glass can set a piece of newspaper on fire, using one small, high-quality solar cell and a concentrator for a lower total cost than hundreds of slightly cheaper cells. (Or you can use the concentrated heat to drive a heat engine, but not in the example we are about to discuss.)
Morgan Solar has a smart variation on this under development. They start with a clever acrylic concentrator that uses pure optical guiding to concentrate solar energy about 50 times, around the same results as a Fresnel lens, but without the need for curves or a non-zero focus. This already moderately concentrated solar is then concentrated further by a much smaller glass concentrator that also needs no air gap. Because neither concentrator requires an air gap, a tiny solar cell is attached directly to the glass.
So you have an eight-inch acrylic concentrator, a glass concentrator the size of an American nickel, and a solar cell the size of a baby’s thumbnail.
Part of the reason I focus (heh) on this rather than competing technologies is the sheer cost-cutting ingenuity. The major component is an inexpensive acrylic lens, which they ought to be able to manufacture more cheaply than high-quality Fresnel lenses. They add extremely small, high-quality components to increase output, without substantially increasing costs. The end result is a product that ought to be inexpensive but high quality, giving not just a low gross cost, but a low cost to output.
It is a truly modular concentrator and solar cell integrated into a single lightweight flat panel. It is suitable for rooftops or parking lots or solar farms, if economies of scale in installation and maintenance suggest that is the best way to go.
I’m not suggesting that this is going to be the winner in the race to produce cheap solar electricity. These are under development, not commercial products; they are not even nearly as far along as many other approaches. Turning them into a commercial products takes more than producing the concentrator/cell combined panels, hooking multiple integrated units into solar panels, choosing suitable trackers, and contracting for installation.
The point is that I could post something like this every day for years. There are that many promising approaches to solar electricity under development, along with promising companies that actually sell commercial products they claim they will make widely available at low prices. It seems highly likely one of these approaches will become reality soon. (By some arguments, one of them has, but is currently available only to large utilities on condition that actual price remains confidential. We will see what comes of that.)
I have no strong expectation that this elegant approach, which I happen to find personally appealing, will be the path solar electricity takes. But the sheer number of promising approaches is good evidence that we will see low-cost solar electricity soon.