Updated with closing stock pricesValue is always the key to finding good investments. For an old oil guy like me, the solar stocks have never represented good value and I have never recommended them. But now, the tide may be changing. Solar stocks have been "darling" investments. They represent the promise of new technology that most people feel will be an inevitable part of our energy future. They are "green" stocks and inspire good feelings in those who own them, as if the very act of investment somehow helps the environment. And with oil continuing to see very high prices, the rush into alternative energy companies has seemed liked the "smart" investment to make. For all these reasons, solar stocks have always seemed to me to be overvalued, running far ahead of what the companies actually could deliver in growth and earnings. Let's look at First Solar ( FSLR), which is far and away the solar company with the largest market-cap and which has always been the benchmark for measuring the sector.