The main point here: Germany doesn’t get an enormous amount of sunlight, relatively speaking. Its annual solar resources are roughly comparable to Alaska’s. Just about every single region in the continental United States has greater solar potential, on average, than Germany.

Yet despite those limitations, Germany has still managed to be the world leader in solar power. At the end of 2012, the country had installed about 30 gigawatts of solar capacity, providing between 3 percent and 10 percent of its electricity. The United States, by contrast, has somewhere around 6.4 gigawatts of solar capacity.

Why the difference? Policy is the big factor. The German government has heavily subsidized renewable energy for years through a variety of measures. Perhaps most crucially, the country’s ‘feed-in tariffs