|Fig. 1: An image depicting Earth's energy cycle powered by the Sun. (Courtesy of the DOE. Source: Wikimedia Commons)|
For centuries, astronomers have recognized the Sun as the heart of our solar system. Ultimately, this yellow dwarf star is the source of all energy on Earth, as seen in Fig. 1. Its rays breath life into plants, which provide oxygen and food for the entire animal kingdom. Dead organisms and waste products deteriorate into the fossil fuels used to power much of the world. Scientific research asserts that these fossil fuel emissions lead to air pollution and acid rain.  If these emissions greatly harm the planet, why dont we return to the root of our energy? As an inexhaustible and clean energy source, solar power presents a viable solution for the growing demand for carbon-neutral energy.
Each hour, the sun provides more energy to Earth than we need to meet an entire years worth of global energy demand.  Anywhere that receives sunlight is capable of harnessing the sun's energy for solar power with the proper technology.  World energy consumption in 2050 is estimated to more than double from consumption in 2001, and in order to stabilize the atmospheric concentration of carbon dioxide - a potent, greenhouse gas - climate scientists predict that by 2050 we will need to derive more energy from carbon-neutral sources than was produced from all of the energy sources combined in 2001. 
Despite the growth of the solar energy market, the technology needed to convert the suns rays into usable power is still widely perceived as too inaccessible and inefficient for use by the average consumer. Solar energy, whether solar-thermal or solar photovoltaic, can only be received while the sun is shining, which means that a storage device is required for use at night and during cloudy or chilly weather. The availability of solar energy also varies geographically, as depicted by the map of annual average daily total solar resources in Fig. 2.
|Fig. 2: This map shows the resource available to a photovoltaic panel oriented and tilted to maximize capture of solar energy. (Courtesy of the DOE, Source: Wikimedia Commons)|
In addition to the unreliable generation, the technology can be expensive and requires a lot of space to collect the energy at valuable rates to support power grids.  As of 2011, The best photovoltaic solar panels were estimated at forty-three percent efficiency. In order to convert sunlight into electricity, these panels require expensive semiconductors that use rare earth minerals including - tellurium, gallium, and indium. 
All of this is not to say that solar power cannot be successfully implemented as an alternative to cheaper and dirtier fuels. Rather, this paper aims to highlight the importance of private funding and governmental backing to bring the cost of photovoltaic cells to grid parity - the point at which the cost of producing power from solar panels will be equal to or less than buying from the grid. 
The U.S. Department of Energy launched the SunShot Initiative in 2011 with the goal of making solar energy market-competitive with traditional generation by 2020 without subsidies. As of September 2017, the U.S. Department of Energy announced that the solar industry has already met SunShot's 2020 utility-scale price target of 6 cents per kWh.  Moreover, the department reports that Tesla and Panasonic are working to create photovoltaic cell technologies that will drive cost down to $0.4/W.  The Department of Energy maintains commitment to driving down residential and commercial PV, and they are focusing research on remaining challenges of grid reliability, resilience, and storage.  Due to economies of scale, higher production of solar technology will drive lower costs and higher efficiencies. As the production costs of the panels continue to drop, states and private interests must take aim at the soft costs of customer acquisition, installation, permitting, financing, and grid integration.  Several states have attacked these barriers by offering aggressive retail rates for grid pricing and credits for installations.
No state's clean power goals compare to the aggressive renewable energy targets set by Hawaii in 2016. Hawaii aims to generate all of its electricity from renewable sources by 2045. The states geographic isolation imposes high costs for the import of fossil fuels, and as the most fossil-fuel dependent state in the country, Hawaiian electric bills are nearly three times higher than those of consumers in the continental U.S.  In 2016, Hawaii managed to generate 26% of its electricity from renewables - with over a third of this clean electricity from rooftop solar panels.  The Public Utility Commissions net energy metering drove private panel installations by crediting customers for excess electricity at a retail rate.  Hawaiian Electric anticipates that this program will invite nearly 2800 more private, solar installations - half of those on Oahu alone. 
In addition to the challenges of reliability and grid support, Hawaii faces the unique issue of grid interconnectivity across the island chain. The Oahu-Maui Grid Tide Project, which has a projected cost of $526 million, would connect the electric grid of those islands by cable for maximized production of utility-scale, renewable energy plants.  By aligning government regulations and policies with their clean energy vision and devoting resources to the improvement of grid infrastructure, the Aloha State is setting the standard for government support of renewable energy production.
With proper support, solar energy can be a viable, renewable energy solution and replace damaging sources of electric power. The changeover will take time as the expensive costs of solar energy are remedied. Hawaii's transition to renewable energy generation illustrates some of the hurdles that must be met with committed funding for infrastructure improvements and increased accessibility. As solar options become more familiar and attractive to the everyday consumer, technology companies can offer more options for the appearance of these rooftop panels. Tesla has already installed its Solar Roof upon the homes of several employees. Teslas glass solar tiles in conjunction with their Powerwall battery offer consumers four, aesthetically-pleasing options to match existing home architecture - an attractive, localized solution for the average person.  Aggressive government programs and private support for renewable energy generation will require successful integration of solar power to meet environmental and economic targets.
© Frank Buncom IV. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
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