Although renewable energy sources have recently made their way into the energy mix, they were not always so prominent or even so viable. To understand how the renewable energy movement has gained so much momentum, it is important to reflect on the progress that has been made since a time when the concept of renewables didn’t even have a name.
The main energy source used by our distant ancestors is no mystery. From the discovery of fire through the end of the 19th century, wood was the primary resource used for heating living spaces and cooking food—and there were few alternatives.
We are lucky that the present global population was much smaller in the past, because otherwise and without the significant innovations we have seen in modern times, the supply of wood and the environments that produce it might have been decimated. With advances in scientific research, we can better appreciate the impact burning wood has on the environment more so than our ancestors could, but that knowledge also informs our concept of conservation. Today’s world population would not last long if we still relied on wood alone!
While coal has been characterized as a major source of pollution over the past several decades, the use of coal as an energy source was an important step in the evolution towards renewables. It powered the railway infrastructure that connected the East Coast to the West Coast and made widespread interstate commerce possible. It also ushered in the Industrial Age and made factory production a reality.
Paradoxically, the explosive population and economic growth fueled by coal in the previous two centuries led to a basic standard of living that fostered the research now opposing continued use of coal. Not only is coal exhaustible but the air pollution caused by burning it has been linked to human health and environmental problems.
Around the middle of the last century, petroleum began to be used for industrial energy production, in addition to being used as a fuel source for vehicles. The fact that it is an energy-dense material makes it especially valuable, but it has the same disadvantage as coal in that it causes significant air pollution when burned.
The known limits of petroleum and its impact on the environment have spurred a move towards cleaner and longer-lasting alternatives.
The first notion of somewhat renewable energy resources first emerged in the late-19th century in the form of hydroelectric power. Hydroelectric dams convert the potential energy of moving water into electricity in a way that mimics the longevity of renewable sources—as long as the water continues to flow—but there is a downside. Hydroelectric dams have significant negative impacts on animal habitats and the environment.
Green natural gas (or Biomass as opposed to fossil-fuel natural gas) is another recent innovation that has attempted to address the factor of cleanliness in energy production. Even though it is regarded as renewable, as its inherent energy comes from the sun, it is still not a perfect solution. The search continues for even cleaner sources of energy.
Although Americans rely on renewables only for a small percentage of energy production, we are at the beginning of what may become the ‘Renewable Era’. The application of wind, solar, and geothermal power has only gained traction recently, but these resources all have the benefit of being both clean and inexhaustible. Add to those the development of affordable battery storage, and the future is looking bright for clean, renewable energy sources.
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