They were too simple to power anything beyond a calculator. However, those calculations rapidly became more and more sophisticated. By the mid-1970s, microprocessors were performing computations for small computers. Continuing price drops could then be driven by private demand. Accompanied by falling costs, this led directly to the information revolution.
Integrated circuits are now dirt cheap and CPUs are ubiquitous in our homes, cars, and workplaces.
But if the government had not purchased huge quantities of chips before they were cheap enough for commercial applications, the technology might never have become cost-effective. The information revolution would have been delayed, perhaps indefinitely. Every time the volume of solar cells has increased in the past, the cost has fallen. Convincing evidence shows that this learning curve will continue as it has with computer chips. The consumer market already is there, just waiting for the price of solar cells to drop.