The Future of Space Based Solar Power
Imagine if there is a technology out there that could provide uninterrupted transmission of power with zero greenhouse gas emissions compared to oil, gas, and coal plants and almost zero hazardous waste to our environment. This is entirely possible based on existing technological principles and known physics, with no new breakthroughs required, and there is an emerging worldwide competition to develop this technology.
The concept of Space Based Solar Power (SBSP) was introduced by American scientist Peter Glaser in 1968. He proposed the idea of placing large solar panels in geostationary orbit around Earth to capture solar energy without the limitations of atmospheric interference or nighttime darkness. The collected energy would then be converted into microwave or laser beams and transmitted to receiving stations on Earth, where it could be converted back into electricity for practical use.
Background
Between 1995 and 1997, NASA undertook a comprehensive assessment to investigate concepts and technologies related to space solar power (SSP). NASA’s Marshall Space Flight Center led an interdisciplinary team comprising internal and external experts in the 1998 Space Solar Power Concept Definition Study (CDS). This study aimed to identify commercially feasible SSP concepts while acknowledging potential technical and programmatic challenges. Subsequently, in fiscal year 1999, NASA executed the Space Solar Power Exploratory Research and Technology (SERT) Program to further advance the investigation.
The SERT program concluded that the concept of space-based solar power had significant potential to provide clean and reliable energy. Still, it also comes with a price of substantial technical obstacles and excessive costs. The program highlighted the need for advances in solar cell technology, wireless power transmission, and materials science to make space solar power economically viable.
The SERT program laid the foundation for continued research and discussions on the feasibility of space-based solar power. While the program did not lead to immediate implementation, the research and insights have influenced subsequent studies and discussions on Space Based Solar Cells.
Design Elements
Space-based solar power essentially involves three core components
Step 1: Capturing solar energy in space using reflectors or inflatable mirrors, directing it onto solar cells or thermal systems for heating.
Step 2: Transmitting power wirelessly to Earth via microwave or laser beams.
Step 3: Receiving the transmitted power on Earth using a rectenna, a specialized microwave antenna.
Challenges To Overcome
Despite the concept being extensively studied for over 50 years, there is no doubt about technological feasibility. Still, there are other minor and major challenges in terms of environmental, political, legal safety, and economic security, some of which include large-scale robotic maintenance and assembly, the environmental impact of installing such large rectennas on the ground, incorporating multinational cooperation and collaboration between difference nations, public opinion on implementing such technology and the safety aspects of it and most of all overcoming the barrier of high-cost space launch. When the space shuttle was in operation from 1981- 2011, it cost nearly 54000 US$ /Kilogram to launch a payload. For a SpaceX Falcon 9, the rocket used to access the ISS, the cost was just 2,720US$ /kilogram. Starship has proved that a low-cost space launch can be achieved, accelerating future large-scale applications like Space-Based Solar Power developments.
Who will be the first to implement this technology successfully?
Japan and JAXA (Japanese Aerospace Exploration Agency) have been trying to turn this science fiction idea into reality for years. They plan to run an experiment around 2025 to see if power can be transmitted from outer space to the ground using small satellites that will be used to send it to ground-based receiving stations from hundreds of kilometers away.
In May 2022, a group of researchers from Caltech successfully demonstrated the ability to wirelessly transmit power in space and beam detectable energy to Earth for the first time. They successfully detected the electrical signal from their satellite MAPLE, one of three pivotal technologies being tested by Caltech’s Space Solar Power Project.
Furthermore, China has bold aspirations to construct a space-based solar power station. Through its proposed new program called SOLARIS, The European Space Agency (ESA) will take the next step in pursuing space contributions to this vision; it will explore the feasibility and potential of Space-Based Solar Power.
As governments, businesses, and societies work collectively towards the ambitious net-zero target, space-based solar cells emerge as a compelling option to accelerate the transition to cleaner and more sustainable energy sources.
