Overview of The Renewable Sources of Energy in The Us

The U. S. Department of Energy estimated 404 gigawatts of wind energy capacity across the country by 2050, up from 89 GW today, if electricity demands hold steady that would fulfill one third of the energy demands of the entire country. But wind power isn’t booming everywhere, the reason could be this formula: P (power) = Cp*1/2*p*A*V3, where V is wind speed, A is area of the rotor, p is the air density and Cp has a max. value of 0. 59. This means if wind speed is doubled, power would increase by a factor of 8. Hence it makes sense utilities are prioritizing building wind farms in places where the resource is most intense. Figure 1As you can see in the map, the areas in red and purple, the great plain states have the fastest wind speeds and most energy available for harvesting. Texas alone with 22. 6 GW of installed capacity, would rank sixth in the world today in total wind capacity if it were its own country.

With all the various governmental incentives and policies, in short solar has won in the United States. Solar accounts for 55% of all electricity added in 2018, which is more than any other type of electricity added so far in 2018. Figure 2The Solar Energy Industries Association (SEIA) report notes that a bulk of the installed capacity comes from utility scale projects, which means this power is going to the grid unlike rooftop solar. Non-residential solar was the second largest area of growth. This growth comes despite 30% tariffs the Trump administration has levied on imported solar panels earlier this year. Rising U. S. solar investments mirror a larger global trend. In 2017, solar energy attracted $160. 8 billion in investment, according to data from United Nations Environment Program, outpacing nuclear and fossil fuels.

Hydropower provides more energy than any other renewable in the U. S. at 7. 5%. Unlike solar that has the most potential out of all the renewables, there are only so many rivers to build dams. The U. S. built a large number of dams across its rivers in the 20th century, as a result growth in hydropower capacity has ‘flatlined’ since the early 1990’s. With the focus now on growth of renewables, that growth has picked up again. Hydropower looks promising as unlike solar and wind hydro provides steady and predictable generation that can serve as the backbone of a diverse energy mix. This baseload type delivery makes hydro an important counterpoint to the variability of solar and wind. Hydro for energy storage: As wind and solar continue their growth, the need for storage solutions is a key for their grid integration. Hydro serves an important role here, when the grid is producing power in excess, it can be used to pump water from the lower basin to the above basin. When electricity needs to be produced, water flows from the upper basin to the lower basin spinning a turbine and generating electricity. In 2014 the U. S. had about 22 Gigawatts of pumped storage hydropower, which made up a staggering 97% of all utility scale storage solutions.

Geothermal is naturally occurring reservoirs of hydrothermal energy. It finds its way to the earth’s surface in three ways- volcanos and fumaroles, hot springs and geysers. The most active geothermal areas are found along major tectonic plate boundaries where most volcanoes are located. Most of the geothermal power plants are in western states and Hawaii, where geothermal sources are close to the earth’s surface. California generated the most electricity from geothermal. The United States leads the world in generating electricity from geothermal, it produces 17. 4 billion kilowatt-hours or 0. 4% of the total electricity produced.

Biomass is plant material and animal waste that can be converted to biogas or into liquid biofuels like ethanol and biodiesel. These fuels can then be used for automobiles or for producing electricity. In 2016, 4. 8 quadrillion British thermal units of energy derived from biomass were consumed in the U. S. 43 Gigawatts of electricity was generated from wood and wood derived fuels in 2017 making it the second largest non-hydroelectric renewable energy source after wind. As we deplete our oil and coal reserves making them more expensive, biomass can be viable alternative. It produces fewer carbon dioxide but it produces harmful methane gas which is 72 times more potent than carbon dioxide as a greenhouse gas.