Leveraging Space Technologies to Achieve SDG 7- Affordable and Clean Energy

Source: The American Society of Mechanical Engineers

The Sustainable Development Goal 7 (SDG 7) aims to ensure access to affordable, reliable, sustainable and modern energy for humankind.

To effectively monitor the progress of SDG 7, the United Nations developed five targets and five indicators. Three of the targets are outcome-oriented, while the remaining two are the means of achieving these targets.

The three target-oriented targets include:

  • Universal access to affordable, reliable and modern energy;
  • increase the global percentage of renewable energy;
  • double the global rate of improvement in energy efficiency. 

The two means of achieving these targets include:

  • Enhancing international cooperations to facilitate access to research, technology and investments in clean energy; and 
  • Expanding and upgrading energy services for developing countries

Global clean energy initiatives

According to a 2019 report by the International Energy Agency, (IEA) International Renewable Energy Agency (IRENA), World Bank, United Nations Statistics Division, And World Health Organisation (WHO), the world is making progress towards achieving SDG 7 but will fall short of meeting the targets by 2030 at the current rate of progress.

Furthermore, the report highlights progress made in enhancing access to electricity by several countries, particularly in Asia and Africa. As a result, the global population without access to electricity decreased to about 840 million in 2017 from 1.2 billion in 2010.  However, the Covid 19 pandemic is set to disrupt the progress made in this goal, as those lacking access to electricity is set to increase in the coming years, pushing several countries (especially in Asia and Africa) far away from achieving the global goal by 2030.

Space technology, particularly the Global Navigation Satellite System (GNSS), are critical to infrastructure monitoring, especially regarding global energy network, power grid synchronization, seismic surveying, and identification of optimal sites for renewable energy production. Furthermore, Earth observation satellites can also improve solar and wind energy production forecasting to estimate the amount of energy needed from other sources.

Space Solar Power

Every hour, the sun emits more energy than the entire Earth consumes in a year. To put that into perspective, explaining science explained that every hour, the earth receives 173,000 TWh of energy from the sun, and in 2017, humanity consumed 160,000 TWh. Without a doubt, solar energy is more than sufficient to meet the entire energy requirements of everyone. However, the challenge is harnessing and storing it in a cost-effective way.

Currently, most solar panels average less than 20% efficiency, meaning they can only trap about 20% of the solar energy that they are exposed to. 

Moreover, solar energy harnessed directly from orbit is five times more powerful than when it is collected on earth. Several factors are responsible for this, including nighttime darkness, cloud cover, filtration of the solar energy by the atmosphere, etc. These factors and many more necessitate a space-based solar power (SBSP) system. The SBSP system ( e.g. powersats), can typically receive non-ending solar energy, allowing them to operate at maximum efficiency throughout their design life. Powersats are designed to last fr about 30 years. Within this period, the modules lose about 18-20% of their total design capacity. However, because the powersat comprises smaller modular solar panels, when certain modules begin to lose efficiency, it is easy to replace them without a significant cost investment.

As a result, power collection is virtually unaffected by the day and night cycles of the sun, with only minor effects from an orbital eclipse due to the periodic alignments of the sun, Earth, and moon. This makes space-based solar power a viable energy source for the future.

An SBSP system is comprised of a solar power satellite (or powersat), a satellite made up of several modules outfitted with lightweight photovoltaic solar panels. This powersat can transmit the solar energy trapped inside the photovoltaic panels within the modules to a ground receiving station. The energy can be transferred from the solar power satellites to the receiving stations and then between receiving stations in just seconds.

However, a major challenge to the SBSP concept is the cost of space launches, the amount of material that would need to be launched, robotic assembly and safety. Hopefully, with the rapid advancement in technology, new materials would be designed, which would increase the efficiency and feasibility of space-based solar power.