As discussed in a previous post, renewable energy has and will continue to be increasingly important in our world. Earlier, we detailed four of the major types of renewable energy: solar, wind, hydroelectric, and geothermal. In this post, we’ll examine three additional sources.
Human can generate energy from the ocean in two main ways. The first, tidal power, involves the use of the natural motion of seawater to spin turbines, a process that creates energy. This method of power generation, which combines hydroelectric and wind technologies, has been implemented in certain coastal regions that include the eastern seaboard of the United States and Western Europe.
The second type of ocean power relies on the sun’s warming of seawater to produce thermal energy. Through the use of one of several systems, humans can then convert this energy into electricity.
The advantages of tidal power start with the high level of predictability of the earth’s tides. With this knowledge, engineers can design systems that generate electricity in the most efficient way possible. Other benefits of tidal power include the fact that it draws on a sustainable source—ocean water—and even when there is little wave activity, it produces significant amounts of energy.
In regard to ocean thermal energy, the main advantage is that—unlike with some other forms of renewable energy—the systems generate power 24 hours a day. In the process, certain types of thermal energy systems also convert saltwater into freshwater, which can then be distributed to local communities.
Tidal power technology works best when located in coastal environments that have widely varying tidal ranges. Unfortunately, only a few areas in the world meet this standard, a factor that significantly limits the technology’s potential application. Another concern is that ocean-based construction can cause irrevocable damage to marine ecologies. The main drawback, though, is the cost. Governments have been hesitant to invest in what is still an expensive technology, particularly considering that cheaper alternatives continue to be available.
Many of the same barriers—a lack of suitable areas, harm to ecologies, and high costs—exist with ocean thermal energy. The pumping of seawater to the ocean’s surface also requires large amounts of energy, which negate certain environmental benefits of this method of power generation.
The term “biomass” refers to waste organic material that can produce energy by being burned. Biomass in the form of wood has helped to power human civilizations for millennia. Apart from wood, other examples of biomass include leaves, grass, animal feces, and even bone, which people who live in regions without much forestation may burn to create energy.
According to the International Energy Agency (IEA), in order for a type of energy to be considered renewable, it must be created via natural processes that replenish more quickly than they are used. Provided that humans continue to replace harvested vegetation fast enough, plant-derived biomass will continue to offer a sustainable source of energy.
In terms of wood, the advantages of burning this type of biomass include lower heating costs and minimal carbon emissions as compared to fossil fuels. What’s more, wood burning can offer these benefits while producing heat at a rate similar to that achieved by modern heating systems.
While many countries have implemented laws that aim to prevent deforestation, certain regions of the world still experience the over-harvesting of trees. In regions like these, where consumption exceeds replenishment, plant-derived biomass is not a true renewable source of energy, according to the IEA’s definition.
Returning to the subject of wood, despite its affordability and low carbon emissions, this form of biomass has some drawbacks. Some people find themselves reluctant to burn wood for energy due to maintenance concerns. In addition, homeowners interested in a wood-burning system may run into certain bureaucratic obstacles. In some communities, for instance, one must obtain permission from local officials before even installing such a system.
Produced through the processing of organic material, biofuels are only considered renewable when derived from plants that regrow each year. Biofuels have increasingly carved out an important niche in the modern energy sector. In 2012, 7 percent of the transport fuel consumed in the United States came from this source.
The production of biofuels does not rely on only one type of crop. Instead, humans can leverage different types of plant life to create this power source. This diversity means that a wide variety of places around the world can produce biofuels using the crop that grows best in their location. As countries reduce their need to import sources of energy, they can also reduce transport-related carbon emissions.
Despite releasing lower amounts of carbon, biofuels’ energy output is poor when compared to fossil fuels. Satisfying the world’s power demands thus requires that biofuels be produced in larger quantities than their fossil fuel counterparts. Due to the increased emissions caused by this heavy production, many experts do not view biofuels as a long-term solution to the world’s energy needs.