T. J. Rodgers discusses the promise and pitfalls of the most popular alternative-energy sources (other than solar). Ethanol? Rodgers says it’s a “total waste.” However, bioengineering and genetic engineering that address the entire corn plant, rather than just the fruit, hold promise. Wind power? Rodgers says it produces high energy volume while remaining cheaper per kilowatt hour than solar. Nuclear? Not only is it cheap and efficient — it’s safe.