When you think power generation in the early 1900s, coal and steam generally come to mind. But in Alexis Madrigal's upcoming book, Powering The Dream: The History and Promise of Green Technology, he shows that people were trying to find environmentally friendly alternatives via ocean waves in the nascent days of household electricity.
Madrigal recounts the adventures of Terrence Duffy, Alva Reynolds, and Fred Starr, three men who sought to use the motion of ocean waves to generate power via motion or air compression. Starr, in particular, played up the environmental perks of such technology all the way back in 1907:
Starr went on to declare that by December 1908, "Los Angeles will be a smokeless and sootless city, clean pure. It will be made so by all the power and heating plants being supplied with power and heat from the ocean waves by the Starr Wave Motor."
Obviously this didn't pan out so well, but it's kind of cool (or possibly demoralizing) that clean energy was a consideration even before global warming entered the international lexicon. For the full excerpt from Madrigal's book, be sure to check out [Wired].