With the Earth’s climate and ecological systems essentially fueled by sunlight, including the winds and ocean currents, it seems natural to ask whether, or not these resources are directly accessible for powering machines. The answer dates back to antiquity wherein winds were used to power ships and pump water, and water was used to run mills for grinding grains. More recently, but still more than a century ago, the workings of photovoltaics were described, ushering in the use of solar panels to generate electricity. Thus, solar and mechanical means of power generation for human consumption certainly exist. The remaining question is whether or not such direct harnessing of heat and mechanical energy can replace the use of conventional fuels for powering human endeavor.