It may come as a surprise to many people but solar photovoltaic cells are not new. They were first discovered in 1839. There have been many breakthroughs since then but the advancements are getting smaller. In Europe, large solar plants cover 1000’s of acres and have for years. There may be a company or university that claim to be on the verge of a breakthrough but there always will be. If you put money down on a solar system today, your ROI will be the same today as tomorrow, a year from now, or ten years from now. Advancement in technology or price in the future will never mean you’ve made a bad investment today in solar technology today.
With all the advancements being made we are still using silicon crystal which is a very old technology. We have found ways to make them cheaper and a bit more efficient but they are still made out of sand.