Why solar power is the next big thing: Here's the math

NUCLEAR FUSION: Solar energy is created by nuclear fusion. That power takes place almost infinitely in the Sun, about 150 million km away from us. Fusion occurs when protons of hydrogen atoms violently collide in the sun's core and fuse to create a helium atom. This process, known as a PP (proton-proton) chain reaction, emits an enormous amount of energy. To put that energy in perspective, 430 quintillion Joules of energy from the sun hits the earth each hour. The whole of humanity uses only an equivalent of about 410 quintillion Joules energy for an entire year.

AWESOME INVENTION: In the 19th century, scientists discovered the photoelectric effect, which is the principle behind modern solar panels. In 1839, French physicist Alexandre-Edmond Becquerel observed that certain materials produced a small electric current when exposed to light. This discovery was later expanded upon by other scientists, including Albert Einstein, who won the Nobel Prize in Physics in 1921 for his work on the photoelectric effect. Today, solar energy is commonly used to power spacecraft, including extra-terrestrial rovers and the International Space Station.

PRACTICAL APPLICATIONS: The first practical solar cell was invented in 1954 by American researchers Daryl Chapin, Calvin Fuller, and Gerald Pearson, who developed a silicon-based solar cell that could convert enough sunlight into electricity to power small electrical devices. Since then, solar energy technology has continued to evolve and improve. New materials and designs are being developed to boost efficiency and reduce costs. Today, solar energy is a widely used and important source of renewable energy around the world. Photo taken on February 3, 2021 shows workers pushing assembled solar panels, which will be used to build a floating solar power farm on Tengeh reservoir, into the water in Singapore. It forms part of the land-scarce city-state's push to build floating solar farms to cut greenhouse gas emissions.

HOW BIG SHOULD SOLAR PANELS BE TO POWER THE ENTIRE EARTH? Calculating it is a complex task. It depends on several factors, including the efficiency of the solar panels, the amount of sunlight available in different regions, the role of batteries, the overall energy demand and the like. However, it is possible to make a “guess-timate” based on some assumptions and rough calculations. This photograph taken on January 22, 2021 shows a worker pulling a cable along a floating solar power farm at sea, off Singapore's northern coast just across the Malaysian state of Johor.

GLOBAL ENERGY CONSUMPTION: According to the International Energy Agency (IEA), the total global energy consumption in 2020 was approximately 170,000 terawatt-hours (TWh). Assuming an average solar panel efficiency of 20 per cent (conservative estimate) based on current and widely available technology, we can calculate that 1 square metre of solar panels can produce approximately 200 watt-hours of electricity per day. This means that to produce 170,000 TWh of electricity per year, we would need approximately 20,000 square kilometres (sqkm), or 20 billion square metres, of solar panels.

POWERING THE ENTIRE PLANET: So to satisfy the world’s total energy consumption (in 2020), we’ll need to cover 20,000 km² with solar panels at existing efficiency (20%). For perspective, 20,000 km² is 27 times the size of the land area of Singapore (729 km²) — though it’s only about 3 per cent (1/34) of the total size of the land area of Texas (total 695,662 km²), or about 1/5 of the Philippine island of Mindanao (97,530 km²), or 1/21 of the land area of the US state of California (423,970 km²). Solar panels need not be on land. Photo shows a floating solar power farm in Singapore.

SCALE: To put this in perspective, the total land area of the Earth is approximately 148,940,000 square kilometers, which is equivalent to 148,940,000,000,000 square meters. Therefore, we would need to cover approximately 13.5 per cent of the Earth's land area with solar panels to generate enough electricity to power the entire planet. Photo shows a man works at a solar power plant in Mikir Bamuni village, Nagaon district, northeastern Assam state, India, Feb. 18, 2022.

US SOLAR: Residential daily consumption of electricity is 12 kilowatt-hours (kWh) per person in the US, according to the Department of Energy. One estimate has it that if all parking lots and roofs of Walmart stores were to be used to tap solar power, it would generate enough electricity to power up to 20 per cent of the total energy use of the US, which in 2022 was about 4.05 trillion kWh, the highest amount recorded and 14 times greater than electricity use in 1950. This is a simplified calculation that does not take into account other factors such as the need for energy storage, the variability of sunlight in different regions, and the technical and economic feasibility of building such a large solar panel farm. Nonetheless, it provides a rough estimate of the scale of the solar energy potential on Earth.

JUMP IN CAPACITY IN US, CHINA: In early 2011, solar power comprised less than 0.1% of the US electricity supply — with just 3 gigawatts of installed capacity. This went up to 1% by 2017, with installed capacity of more than 47 gigawatts. As of the end of 2022, the US had 142.3 gigawatts (GW) of installed solar power capacity, according to the US DoE. By comparison, China’s solar prowess is staggering. With a whopping 392 GW, the country is the largest producer of solar energy in the world. In 2022, China installed 107 GW of solar output — roughly equivalent to the entire historical installed capacity of the US — and is likely to add around double that in 2023, according to a BloombergNEF report. Moreover, it has set goals to install 108 GW of solar power this 2023. Photo shows solar panels at a plant co-owned by Longi Green Energy Technology Co. and China Three Gorges Corp. in this aerial photograph taken in Tongchuan, Shaanxi Province, China. Longi is the world's largest producer of solar wafers and the world's largest solar company by market value.

EXPLOSIVE GROWTH: One study shows that the remarkable surge in solar power adoption indicates that the majority of European Union (EU) nations are on track to achieve their 2030 renewable energy goals well in advance, according to recent data. This promising trend bolsters optimism in the global effort to combat emissions. In 2022, the European Union witnessed an explosive growth in solar capacity, with the addition of 41 gigawatts—an impressive 40 per cent increase compared to the previous year. Projections indicate that this upward trajectory will continue, with solar capacity expected to exceed 50 gigawatts in 2023. Data from the SolarPower Europe advocacy group, based on the latest national targets, reveals that 23 countries are positioned to meet their solar installation objectives by 2027. This underscores the EU's journey toward accelerating the transition to clean and sustainable energy sources. The EU story shows the world CAN achieve net zero emissions and withdraw several hundred gigatons of carbon dioxide from the atmosphere and oceans. And perhaps, by really working together, we can help us get there by around 2050.

TECH IMPROVEMENTS: Utilisation of solar power technology is rising, due to its inherent ability to provide off-grid, distributed power solutions. Experts like Stanford University futurist Tony Seba thinks a significant portion of the world's energy needs could be fulfilled by solar power, while helping mitigate the effects of climate change. A view of the Mohammed Bin Rashid Solar farm in Dubai, United Arab Emirates.

ITERATIONS: Further refinements or iterations of solar technology could is ushering in “Solar 3.0” — the next generation of solar technology and energy systems that are currently being developed. The term is sometimes used to describe the evolution of solar energy from its early stages, which focused primarily on the development of solar panels, to more advanced systems that integrate energy storage and other technologies. A community solar power project in Paluan town on the island of Mindoro, Philippines. It’s the first solar-plus-storage microgrid system in Asia to use Tesla’s Powerpack energy storage system installed in 2018 to end power outages on the island.

VERSATILE, FLEXIBLE, DISTRIBUTED POWER: Solar power can be used to generate electricity in a variety of settings, from large-scale solar farms to small rooftop installations. This versatility makes it a practical option for a wide range of applications, including residential, commercial, and industrial use. A view of the Shams solar power project in Abu Dhabi.

COST EFFECTIVE: The cost of solar power has decreased significantly in recent years, making it increasingly cost-effective when compared to other sources of energy. In some parts of the world, solar power is now cheaper than fossil fuels. As the production and energy-generating capacity of solar panels has improved over the last few decades, the cost has dropped dramatically — from $106 per watt in 1976 to $0.38 per watt in 2019. It’s an example of "economies of scale” in manufacturing. Today, solar panels are 94 per cent cheaper than they were in 1989, according to the US National Renewable Energy Lab. Photo shows a Masdar solar power project in Indonesia.

SUSTAINABLE: Unlike fossil fuels, which are finite resources that are rapidly depleting, solar power is sustainable and can be harnessed without causing environmental harm. Solar power does not produce greenhouse gas emissions or contribute to air pollution, which makes it an attractive option for reducing our carbon footprint and mitigating the effects of climate change. A solar power farm in Rizal province, near Manila, Philippines. Vegetables are set to be planted in between the rows of solar panels.

RENEWABLE: Solar power is a renewable energy source that relies on the energy from the sun, which is a virtually unlimited resource. This means that as long as the sun continues to shine, we will have access to this source of energy. Located in a desert near Masdar City, Abu Dhabi, this UAE 10-MW solar power plant generates clean electricity.


WHAT’S NEW: New analysis in energy research by 23 scientists around the world has concluded that, with new technologies and the application of AI-based controls, the world can reach a 100 per cent renewable energy system by or before 2050, most of that could be from solar and wind energy, working alongside batteries. A general view of a solar farm in Abu Dhabi, United Arab Emirates.

HIGH UPFRONT COST: Although solar power has experienced significant price reductions, its initial installation costs remain substantial. It involves the expense of procuring and installing solar panels, batteries, and the necessary supporting infrastructure. Nevertheless, it continues to represent the most cost-effective and secure pathway for nations to achieve both long-term energy self-sufficiency and security, thus laying the groundwork for unparalleled prosperity. The technology and solutions needed are already accessible, and the costs are gradually decreasing. Harnessing the abundant and affordable energy from the sun is already instigating remarkable transformations, reshaping economies and industrial capabilities, and yielding unprecedented advantages.

SOLAR 3.0: It’s as a term that refers to the next-generation of solar technology and energy systems currently undergoing further refinements. The advanced systems integrate energy storage and other technologies into the mix — designed to store excess energy produced by solar panels during the day so that it can be used at night or during periods of low sunlight. Another aspect of the new system is smart grid integration, designed to be integrated into smart grids, which allow for more efficient distribution and management of energy. A view of the Mohammed bin Rashid Al Maktoum Solar Park in Dubai, which is hooked up to the power grid.