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About this Article
Written by: Patrick Gendotti
Written on: April 21st, 2012
Tags: aerospace engineering, material science, mechanical engineering, physics, security & defense, energy & sustainability, photovoltaic, power, solar cell, space
Thumbnail by: Wikimedia Commons/Wikimedia Commons
About the Author
Patrick Gendotti is a senior studying Aerospace Engineering at the University of Southern California. Ben Bova’s Powersat novel sparked his interest in space-based solar power, and he has been a space and science aficionado ever since.
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Volume XIV Issue III > Space-Based Solar Power: A New Path Towards Sustainable, Clean Energy?
Space-based solar power (SBSP) is an idea that has been alternatively promoted and ignored since its inception in 1968. A space-based solar power system is essentially a satellite comprised mainly of solar panels that beams electrical energy down to a collecting station on Earth, which then distributes that energy to the domestic power grid. The primary advantages of SBSP are the cleanliness of the energy collection and generation, the amount of energy provided by such a system, and the energy self-sufficiency acquired by the United States. The glaring disadvantages to SBSP are launch costs, which inhibit both installation and maintenance of the power satellites, restrictive launch geography, and safety hazards. These positive and negative attributes of SBSP must be weighed meticulously to determine the current viability of solar power satellites, with the caveat that technological advances in photovoltaic arrays, reduction of launch costs, and the skyrocketing costs of fossil fuels may tip the balance in favor of SBSP in coming years.

Introduction

Space-based solar power (SBSP) was invented in 1968 and is one of the greenest technologies currently available to produce electric power. A space-based solar power system consists of an orbiting satellite comprised almost entirely of solar panels (Fig. 1) that transmits power to a ground-based collecting station using electromagnetic waves [1]. After installation, the satellite in orbit and the collecting station on the ground have essentially zero emissions, and the installation process itself generates very few emissions. The CEO of Solaren Corporation, Gary Spirnak, states that their proposed SBSP system will have “minimal impacts to the environment,” about the same as “the construction of a similarly sized terrestrial photovoltaic (PV) power plant” [2]. Solaren has negotiated a deal with Pacific, Gas, and Electric, northern California’s largest energy provider, to supply them with 200 megawatts of baseload power by mid-2016 [2]. Other companies have entered the SBSP race: Astrium, a European company, plans on launching a prototype satellite in 2016 and a fully-functional model by 2020, and the Japanese Space Exploration Agency, Mitsubishi Corporation, and Kyoto University have collaborated to test a microwave power transmission system in a simulated space environment this past year, with the ultimate hope of establishing an operational SBSP system by 2025 [3] [4]. While the idea of space-based solar power has been around for over 40 years, barriers to its implementation such as high launch costs, geographical launch restrictions, and safety hazards and unknown risks have contributed to its neglect. However, current research trends indicate that space-based solar power may be a viable option for clean, sustainable, self-sufficient domestic energy production within the next decade.
Wikimedia Commons/Wikimedia Commons
Figure 1: A SBSP satellite concept dominated by the solar panel area.

What is Space-Based Solar Power?

Space-based solar power is a blanket term covering satellite systems that have large solar arrays for the express purpose of collecting large quantities of solar energy. The remainder of the satellite consists of an antenna to beam the collected solar energy down to a power station on Earth, as well as various sensors and internal electronics. The wavelength of the electromagnetic waves transmitted from the satellite must be of sufficient size to leave unharmed flora or fauna surrounding the station, restricting the transmission wavelengths. Congress has not passed any specific requirements that pertain directly to space-based solar power transmission wavelengths, although similar scenarios with potentially dangerous electromagnetic radiation (like cell phone infrared radiation) have precipitated usage laws and minimum safety standards [5]. Aside from the requisite ground-based and space-based infrastructure, a company or institution would be needed to actively operate the SBSP system. For the satellite, operation would involve monitoring the status signals and ensuring its position in orbit remains stable. Likewise, maintenance of the ground facilities is necessary, although management of the ground facilities is not as critical since the system is largely autonomous.

Why Not Now?

Solar technology has made great strides since its invention and relative proliferation in the 1970’s, so you may wonder why the United States and other nations are not currently beaming down power from the skies. These advances have increased the feasibility of SBSP and reduced the scientific community’s general perception of SBSP as some lunatic fantasy at worst, and as a far-fetched, futuristic, and inherently foolish expenditure of time and resources at best. The following sections discuss some advantages and disadvantages of SBSP, as it currently stands. SBSP has numerous advantages over current energy generation technologies: it is immaculately clean, abundantly available, and eminently renewable. SBSP also supports domestic energy production, creates green jobs, and beautifies the landscape.

Clean, Green Energy

One of the primary advantages of space-based solar power is that it is one of the cleanest types of energy available. The sun is the primary source of energy for the Earth; solar energy that is harvested directly from the sun’s rays can be seen as the cleanest and most efficient form of energy production, since all energy the Earth receives comes ultimately from the sun. Detractors of space-based solar power may argue that the production of the solar panels themselves and the placement of the satellites in orbit may create hazardous and toxic by-products, but the damage done to the environment and the threat these materials pose to ecosystems is insignificant compared to the continued use of fossil fuels and their macro-scale impact on climate change.