I appreciate Carl's post about alternative energy sources and inventions not being used. After studying Stirling engines and examining the economics behind alternative energy sources, I realized that the economic realities are the real problem. The reality is that the cost of initial investment is high, the rate of return is low and the risk is high. This translates into a bad investment.
Energy prices are low and it is difficult to break into the market.
I have always been on the lookout for a new alternative energy idea that would enable me to start a profitable company capable of sustaining the difficult times. I have not yet found one. Nearly always, the new invention or idea has problems. For example, electric cars may be thought of as friendly for the environment, but you still have to charge the car up with energy from the power company, if you don't have a solar power charging station. This energy is oftentimes from coal or oil.