Constraints On Solar Power Satellites Are More Ground-Based Than Space-Based – Universe Today

Analysis of Space-Based Solar Power and its Contribution to Sustainable Development Goals

Introduction: Aligning Space Technology with Global Goals

Recent advancements, including successful demonstrations by Caltech’s Space Solar Power Project, have increased interest in Space-Based Solar Power (SBSP) as a viable contributor to global energy needs. This technology aims to harness the constant and abundant solar energy available in geostationary orbit (GEO), directly supporting the objectives of SDG 7 (Affordable and Clean Energy). A new analysis by a team of Italian and German researchers investigates the maximum potential of an SBSP constellation, focusing on logistical and infrastructural constraints rather than purely technical challenges. This report evaluates the findings of that study and its implications for achieving key Sustainable Development Goals.

Methodology: Assessing Global Capacity for Clean Energy

The research calculates the maximum power an SBSP constellation could deliver to Earth’s electrical grid. The methodology addresses two primary questions fundamental to scaling up this innovative infrastructure in line with SDG 9 (Industry, Innovation, and Infrastructure):

1. The total number of satellites that can safely operate in geostationary orbit.
2. The amount of power each satellite can effectively transmit to the grid.

A core constraint applied across all scenarios is the Minimum Distance Angle (MDA) of 0.1°, a conservative measure to prevent collisions and radio interference, ensuring the long-term sustainability of orbital infrastructure.

Scenario Analysis: Constraints on Sustainable Infrastructure Development

The study outlines four scenarios to determine the maximum number of SBSP satellites, with each scenario adding progressively restrictive, real-world constraints. These scenarios highlight the challenges of integrating this new technology with existing terrestrial and orbital systems, a key consideration for SDG 11 (Sustainable Cities and Communities) and SDG 9.

1. Theoretical Maximum Capacity: Based solely on the 0.1° MDA, a total of 3,600 SBSP satellites could fit in GEO. This represents the absolute physical limit of the orbital space.
2. Integration with Existing Satellites: Accounting for existing satellites already in GEO and applying the same MDA clearance reduces the number of potential SBSP satellites to 2,509.
3. Geographical and Land-Use Constraints: This scenario limits the placement of ground-based receiving stations (rectennas) to land areas within 30 degrees of the equator. This geographical limitation, necessary for efficient power transmission from GEO, reduces the number of viable satellite locations to 1,771.
4. Socio-Economic and Infrastructure Readiness: The final scenario adds a critical constraint related to terrestrial infrastructure. It limits rectenna placement to areas with a population density exceeding 3,000 people per square kilometer, using this as a proxy for the presence of an electrical grid capable of managing the incoming power. This constraint, which directly relates to the goals of SDG 11, drastically reduces the number of potential satellites to 364.

Power Output and Impact on Sustainable Development Goals

The report calculates potential power output using conservative assumptions, including a 10km² solar panel area and 20% efficiency. While each station could theoretically collect 272 GW, the study estimates a delivered output of 1 GW per station after accounting for significant conversion and transmission losses. Even under the most restrictive scenario (364 satellites), the total power supplied by the constellation would be sufficient to cover 3% of global electricity usage. This contribution has a direct and significant impact on several SDGs:

• SDG 7 (Affordable and Clean Energy): SBSP provides a consistent and powerful source of renewable energy, diversifying the global energy portfolio and enhancing energy security.
• SDG 13 (Climate Action): By providing carbon-free electricity on a massive scale, SBSP can play a crucial role in mitigating climate change and reducing reliance on fossil fuels.
• SDG 9 (Industry, Innovation, and Infrastructure): The development and deployment of SBSP represents a monumental leap in technological innovation, requiring new space and ground infrastructure and fostering new industries.

Conclusion: A Conservative but Promising Outlook for Global Energy

The analysis provides an intentionally conservative estimate of the potential of Space-Based Solar Power. The assumptions regarding energy conversion efficiency and restrictions on rectenna placement present a worst-case scenario. Nevertheless, the finding that SBSP could still provide 3% of the world’s electricity under these stringent conditions is a powerful indicator of its potential. The technology demonstrates a clear pathway to contributing significantly to global sustainability targets. Further international collaboration, in the spirit of SDG 17 (Partnerships for the Goals), is essential to overcome the logistical challenges and fully realize the benefits of this transformative energy source.

Analysis of Sustainable Development Goals in the Article

1. Which SDGs are addressed or connected to the issues highlighted in the article?

   The article on Space-Based Solar Power (SBSP) primarily addresses three Sustainable Development Goals (SDGs):

   • SDG 7: Affordable and Clean Energy: The entire article focuses on a novel method for generating vast amounts of clean, constant solar energy and transmitting it to Earth. It discusses the potential to “cover 3% of the total global power usage,” directly contributing to the global supply of clean energy.
   • SDG 9: Industry, Innovation, and Infrastructure: The concept of SBSP is an advanced technological innovation. The article details the necessary infrastructure, including a “constellation of space-based solar power (SBSP) satellites,” “receiving antenna to collect the microwaves” (rectennas), and the “necessary electrical infrastructure to capture and transmit the power.” This highlights the development of new, sustainable infrastructure.
   • SDG 13: Climate Action: Although not explicitly mentioned, providing a significant amount of clean energy to the global grid is a fundamental strategy for climate action. By offering a constant power source that could supplement or replace fossil fuels, SBSP contributes to mitigating climate change. The potential to provide “3% of the total global power usage” with a clean source implies a substantial reduction in carbon emissions.

2. What specific targets under those SDGs can be identified based on the article’s content?

   Based on the article’s discussion, the following specific SDG targets can be identified:

   • Target 7.2: Increase substantially the share of renewable energy in the global energy mix. The article directly supports this target by exploring a technology that could increase the global renewable energy supply. The calculation that SBSP could “cover 3% of the total global power usage” is a quantifiable contribution to this target.
   • Target 9.1: Develop quality, reliable, sustainable and resilient infrastructure. The article describes the development of a new, large-scale energy infrastructure, including satellites in geostationary orbit and ground-based rectennas. The discussion of constraints like the Minimum Distance Angle (MDA) and land availability for rectennas points to the planning required for developing this reliable and sustainable infrastructure.
   • Target 9.4: Upgrade infrastructure and retrofit industries to make them sustainable, with… greater adoption of clean and environmentally sound technologies. SBSP represents a “clean and environmentally sound technology.” The article’s focus on its feasibility and potential (“the eventual benefit to humanity”) aligns with the goal of adopting innovative technologies to create a more sustainable energy infrastructure.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

   Yes, the article mentions and implies several indicators that can be used to measure progress:

   • Indicator for Target 7.2 (Renewable energy share): The article provides a direct, quantifiable potential indicator: the “3% of the total global power usage” that SBSP could provide. This figure serves as a measure of the technology’s potential contribution to the global renewable energy share.
   • Indicators for Target 9.1 (Infrastructure development): The article implies several metrics to track the development of this new infrastructure:
     • Number of operational satellites: The paper calculates various scenarios for the “number of potential satellites,” ranging from 364 to 3,600. This number can be used as an indicator of the scale of the deployed infrastructure.
     • Total power delivered to the grid: The article estimates that each satellite could deliver “1 GW per station” to the grid. The total power capacity of the constellation is a key performance indicator for the infrastructure’s effectiveness.
     • Land area for receiving stations: The constraint related to the placement of rectennas on land implies that the total area dedicated to this infrastructure is a measurable indicator of its deployment.

4. Create a table with three columns titled ‘SDGs, Targets and Indicators” to present the findings from analyzing the article.

   SDGs	Targets	Indicators (Mentioned or Implied in the Article)
   SDG 7: Affordable and Clean Energy	7.2: Increase substantially the share of renewable energy in the global energy mix.	Percentage of total global power usage covered by SBSP (stated as potentially “3%”).
   SDG 9: Industry, Innovation, and Infrastructure	9.1: Develop quality, reliable, sustainable and resilient infrastructure. 9.4: Upgrade infrastructure… with greater adoption of clean and environmentally sound technologies.	Number of SBSP satellites in operation (scenarios range from 364 to 3,600). Total power delivered to the electrical grid (estimated at “1 GW per station”). Number and total land area of ground-based rectenna stations.
   SDG 13: Climate Action	13.2: Integrate climate change measures into national policies, strategies and planning.	Implied Indicator: Reduction in greenhouse gas emissions resulting from the displacement of fossil fuels by the power generated from SBSP (quantified by the “3% of total global power usage”).

Source: universetoday.com