Haha, wow... What an incredibly narrow view of the world you have. These "laws" are absolutely not nonsense. It is a real, broadly documented effect that the cost to produce goods in a large industry continually declines as a manufacturer learns over and over all the places they can reduce costs. http://www.economist.com/node/...
A manufacturer may come up with a trick to increase yield one year, so that there is 10% less product that falls out of the line after manufacturing due to defects. They may build more factories closer to consumers to reduce delivery costs. They may buy bigger machines to spit out twice as much goods for the same amount of labor, cutting labor costs in half. Their suppliers could get better at making the machines, offering faster machines for the same price - cutting down on overhead costs per part. The mines who supply the silicon could get more customers and invest in better machinery too, similarly decreasing their costs (which they can pass on to the consumer of those materials). Researchers can find new materials (like carbon for solar) that are cheaper than traditional materials. They could double efficiency for the same amount of material, cutting costs in half again.
Companies continually improve their processes to maintain their edge in a competitive marketplace. There is always someone who will come in and undercut you, so you need to be able to continually improve your processes or you will die. The whole phenomenon of continually lower prices was identified in the 1960's, and has repeatedly been shown to be valid over long terms. Moore's law for semiconductors is one great example, and solar panels still have huge demand above what we currently need them for. These laws apply to all kinds of things though... I'm sure it applies to tires, paper, pencils, shoes, televisions, LEDs, batteries, windows, magnets, etc. As long as an industry is growing - there will be money to invest in lowering costs.
You do need a place to put solar panels, but every rooftop in the country has more than enough room to power the underlying building with solar using just today's 20% efficient solar cells. We need power at night, but Elon Musk thinks lithium batteries will work just fine, and we have enough lithium to increase our use 20% every single year for 30 years before we'd need to even look for more. Lithium is one of the most abundant materials on the planet and the batteries are easy to recycle. Musk has said he plans on selling 30% of the batteries from his new factory to solar home customers (and he already owns a solar panel factory and a solar installation and leasing company). A solar-driven world seems very, very plausible.
Plus, we literally cannot afford to keep burning fossil fuels. We have no choice but to go carbon neutral and nuclear is not the option. We get free power from the sun. It is absolutely silly not to take advantage of it. Those fossil fuels we love? They were originally plants that grew from the sun or animals that ate plants that grew from the sun. Everything on Earth exists because of the vast power of the sun.