Innovation in Wave Turbines

Innovation in Wave Turbines

Introduction

Countless energy imperatives ranging from the solar flux reaching the earth to minimum temperatures required for the functioning of thousands of enzymes—have always shaped life on Earth by controlling the environment and by setting the limits on the performance of organisms. Deterministic interpretations of energy's role in world history seems to be a natural proposition, with history seen as a quest for increased complexity made possible by mastering higher energy flows. Periodization of this quest on the basis of prevailing prime movers and dominant sources of heat is another obvious proposition. This approach divides the evolution of the human species into distinct energy eras and brings out the importance of energy transitions that usher in more powerful, and more flexible, prime movers and more efficient ways of energy conversion. Perhaps the most intriguing conclusion arising from this grand view of history is the shrinking duration of successive energy eras and the accelerating pace of grand energy transitions (Lieuwen, 2005).

The first energy era started more than 300,000 years ago when the human species, Homo sapiens, became differentiated from Homo erectus, and the era continued until the beginning of settled societies some 10,000 years ago. Throughout prehistory, all efforts to control greater energy flows were capped by the limited power of human metabolism and by the inefficient use of fire. Domestication of draft animals and harnessing of fire for producing metals and other durable materials constituted the first great energy transition: reliance on these extrasomatic energies had raised energy throughput of preindustrial societies by more than an order of magnitude. The second transition got under way only several millennia later; it was not as universal as the first one and its effects made a profound, and relatively early, difference only in some places: it came as some traditional societies substituted large shares of their muscular exertions by waterwheels and windmills, simple but ingenious inanimate prime movers that were designed to convert the two common renewable energy flows with increasing power and efficiency (Roddier, 2009).

The third great energy transition—substitution of animate prime movers by engines and of biomass energies by fossil fuels—began only several centuries ago in a few European countries and it was accomplished by all industrialized nations during the 20th century. That transition is yet to run its course in most low-income economies, particularly in Africa. The latest energy transition has been under way since 1882 when the world's first electricity-generating stations were commissioned in London and New York (both Edison's coal-fired plants) and in Appleton, Wisconsin (the first hydroelectric station). Since that time, all modernizing economies have been consuming increasing shares of their fossil fuels indirectly as electricity and introducing new modes of primary electricity generation—nuclear fission starting in the mid-1950s, and later also wind turbines and photovoltaic cells—to boost the overall output of this most flexible and most convenient form of energy. The second key attribute of this transition has been a steady relative retreat of coal mirrored by the rise of hydrocarbons, first ...