A variety of factors, including global warming and a recent spike in energy costs, have pushed several U.S. states to adopt Renewable Portfolio Standards (RPS). These standards have been the biggest catalyst behind the ever-accelerating clean energy movement. Essentially, they require a states utilities to generate a certain percentage of their electricity from renewable sources such as solar, wind, geothermal, tidal, and other sources apart from conventional fossil-fueled technologies. Promoting Clean Energy As of yet, no one technology has come to dominate the field. That is why states are developing a portfolio of clean energy sources. RPSs are effective because they push utilities to promote clean energy through rebates, loans, and other incentives. Furthermore, many states offer their own government-issue incentives in the form of rebates and tax incentives. Fortunately for we solar enthusiasts, the United States is, overall, a very sunny place and, for this and many other reasons, solar is becoming a dominant force as states try to achieve their standards. State-by-State Standards Different states have very different standards. Colorado (being the first), New Jersey, California, Oregon, and a handful of others are leading the way in terms of percentage. For example, Oregon requires that 25 percent of all their electricity needs are generated from renewable sources by 2025. California, itself the worlds third largest solar market, requires 20 percent by 2010! While these are two high-end examples, many other states have either adopted their own or are working on it in their states legislature. Uniformity Lacking There is no doubt that solar and other renewable technologies are the talk of the town in state capitals around the country, yet a graph of RPSs by state would be quite the smattering of dots. It would be nice to see a more uniform run on renewable energy, but that relies much on the federal governments own RPS which, as of yet, does not exist. However, the federal Production Tax Credit (PTC), has played a big role in motivating large-scale clean energy production, speeding up the realization of RPSs. Unfortunately this and other federal credits, including residential solar rebates, are set to expire at the end of 2008. To find out where your state stands on solar energy, keep an eye out for CalFinder Solars forthcoming State-by-State Rebates and Incentives site.