Natural Gas vs. Solar for Electricity Production
In all societies electrical energy is required to meet the most basic of human needs. Lighting, safety, comfort, cooking, transportation, communications and the basic production that supports our economies all depend on electrical power. 39% of all energy consumed in America, is used in the production of electricity. Electrical utilization is a significant part of a person’s environmental footprint.
The technologies currently employed in the production of electricity in the United States include Coal, Oil, Nuclear Power, Biomass, Hydro Power, Natural Gas, and renewable energies including Wind and Solar Power.
This purpose of this article is to provide a comparative overview of the use of Natural Gas and Solar Energy in electrical generation.
Over 90% of all new energy production added in the United States since the late 1990’s has been based on Natural Gas (source: EIA 2008). As of 2012, Natural Gas was responsible for over 30% of all electrical energy generated in the United States and still growing (source: NREL 2013).
The amount of electricity generated by U.S. utility-scale solar photovoltaic power plants is up more than 100 percent in 2014 over the same period in 2013. That was enough to meet the electricity needs of 1,513,703 average U.S. homes. Over 600,000 homes and businesses have installed solar power. 200,000 of these installations were in 2014 alone. In 2014 solar power accounted for 32% of all new electrical power generation in the U.S.
Source of Useable Electricity
Electrical energy produced from natural gas is the end product. The raw material is the natural gas itself, it is obtained by drilling wells and removing the gas from deep within the earth. The gas must then be processed to remove undesirable impurities in a gas processing plant. From the gas processing plant the gas is then transported to a power plant, usually by pipeline.
The raw material for solar power is the inexhuastable energy of the Sun.The Sun bombards the earth with an almost incomprehensible amount of energy each and every day. An area of approximately 516 sq. ft. is exposed, in six hours, to over 10 times the amount of solar energy than is required to power the average home for an entire day. The best part is that the power of the sun is 100% clean and free.
Types of Electrical Production
1. Steam Turbine – gas is burned to heat water and create steam that in turn drives a steam turbine creating electricity.
2. Combustion Turbine – gas is burned directly in a combustion turbine to create electricity.
3. Combined Cycle – gas is burned in a combustion turbine and the hot exhaust from the combustion turbine is used to create steam and run a steam turbine as well.
Solar Energy is converted into electricity in two ways: photovoltaic and solar-thermal technologies. This article focuses on photovoltaic technology (the main type of solar generation used in the United States). Photovoltaic systems consist of wafers made of silicon or other conductive materials. When sunlight hits the wafers, a chemical reaction occurs, resulting in the release of electricity.
Environmental Impact of Electrical Generation
Natural Gas is a fossil fuel, meaning, it was formed over a period of thousands of years by plant and animal matter being exposed to intense heat and pressure. When Fossil fuels are burned they release stored carbon which results in greenhouse gases being emitted into the atmosphere contributing to global warming. Natural Gas that is not combusted in energy production is released into the atmosphere as methane, also a greenhouse gas. Since Natural Gas takes thousands of years to form, it is a non-renewable resource; once it is used it cannot be replaced.
Solar Power resources are accessible everywhere in the United States, even cloudy or foggy climates, anywhere the sun comes up in the morning. No fuel is burned in the process of converting Solar Energy into electricity. Solar Panels just absorb clean, free sunlight and convert that energy into electricity there are no greenhouse gases produced.
Although Natural Gas is cleaner burning than coal or oil the average emission rates at the power plant level are : 1135 lbs/MWh of carbon dioxide, 0.1 lbs/MWh of sulfur dioxide, and 1.7 lbs/MWh of nitrogen oxides. In addition, the process of extraction, treatment, and transport of the natural gas to the power plant generates additional emissions (source:EPA).
Impact on Water Resources
While the burning of natural gas does not require water, boiler and combined cycle turbine systems require water for cooling and steam generation. Removing water from lakes and rivers as well as the discharge of used water can kill fish and other aquatic life affecting the related ecosystems.
There is also evidence that fracking, a form of natural gas extraction, is having severe adverse effects on the ground water and the overall health of people in areas surrounding the fracking sites.
Impact on Land Resources
The natural gas extraction process can impact an area by causing erosion, landslides, decreased soil productivity and lost habitat for animals and plants.
Utility scale solar competes with existing agricultural land uses, plant, and animal life. Home and commercial solar energy have zero land resource impact.
Since 2012 the price of Natural Gas has steadily increased and will continue to rise as other sources of energy production that are fossil fuel reliant are increasingly scaled back. Increased raw material and production costs as well as inflation will continue to be passed to the consumer in the form of higher and higher energy bills
Solar Energy prices are at an all-time low and continue to drop. The costs of solar panels and related technology for the conversion of solar energy into electricity have dropped by approximately 60% since 2012 and continue to drop.
Improved production techniques and solar cell efficiency guarantee future cost reductions in the solar power generation industry in the United States and globally.