In this blog post, we examine the differences and advantages of solar thermal and solar photovoltaic technologies and explore how they can contribute to solving energy problems as renewable energy sources.
Energy-related issues have always captured our attention. Global warming, carbon dioxide emissions—these problems can no longer be ignored. Regrettably, South Korea’s energy consumption has recently shown the world’s highest growth rate at 10%, and its greenhouse gas emissions also rank first globally. Compared to other developed nations, South Korea has yet to move away from generating energy through nuclear power; as of 2024, nuclear energy accounts for approximately 29% of the country’s energy mix. While nuclear power generation may be highly efficient, it carries significant burdens and inherent risks. The Fukushima nuclear power plant accident on March 11, 2011, and the Chernobyl nuclear power plant accident on April 26, 1986—both rated at level 7 on the International Nuclear Event Scale—demonstrate that nuclear energy production is highly unstable and dangerous.
Therefore, South Korea must now also shift to renewable energy. Renewable energy refers to sources like sunlight, biomass, water, wind, and other regenerative resources—not coal or oil. Nuclear power is not renewable energy. Among renewables, solar thermal and solar photovoltaic seem the most easily applicable to our lives. This is because solar thermal and solar photovoltaic systems are essentially complete once installed. However, most people don’t recognize the difference between solar thermal and solar photovoltaic. They generally just think it’s using the sun’s heat to generate electricity. This article aims to provide the public with more accurate information and the differences between solar thermal and solar photovoltaic, making these technologies feel more approachable. Only then will people likely adopt solar thermal and solar photovoltaic in their actual lives.
Solar thermal and solar photovoltaic are very similar yet distinctly different technologies. The biggest commonality between the two is that both solar thermal and solar photovoltaic power generation use solar energy to produce electricity. However, solar thermal power generation and solar photovoltaic power generation are fundamentally different.
First, solar thermal power is fundamentally a technology that absorbs, stores, or converts solar heat while considering the wave properties of sunlight, using it for heating and cooling in buildings or homes. Systems utilizing solar heat are primarily divided into two types: equipment-based solar thermal systems and natural solar thermal systems. Conventional solar thermal systems operate without any mechanical components, relying solely on the heat received from the sun. This system uses collectors to convert solar energy into thermal energy, which is then used or stored. Passive solar systems, on the other hand, utilize the building’s structure itself for heat collection.
In contrast, photovoltaic (PV) power generation converts the light energy received from the sun into electricity. Simply put, it is a system that directly converts the light energy received from the sun into electricity. The core of this system involves a photovoltaic cell possessing a pn junction structure. When photons from the external environment enter the interior of the photovoltaic cell, the energy inherent in the photons themselves generates electron-hole pairs within the cell. When the charges gathered at each electrode connect to an external circuit, the current flowing within the load provides the energy to operate that load.
As mentioned earlier, our country still lacks sufficient resources and resource development. We cannot continue to rely solely on nuclear power or coal. Therefore, I believe our country must now gradually develop and popularize renewable energy to generate power. Solar thermal and photovoltaic systems are not complicated to install or use, so even if just one were installed per household, significant changes could occur.
So, what changes can we expect when implementing solar thermal and photovoltaic systems in daily life? First, reduced energy costs. While the initial installation cost may be somewhat high, in the long term, it can significantly cut electricity and heating expenses. This would greatly benefit household finances. Second, it contributes to environmental protection. Using solar energy reduces fossil fuel consumption and consequently lowers carbon dioxide emissions. Third, it increases energy self-sufficiency. It reduces dependence on external energy sources, enabling individual homes or buildings to produce their own energy.
For these reasons, solar thermal and solar photovoltaic energy will play a crucial role in our future energy strategy. Therefore, this article attempts to explain the similarities and differences between solar thermal and solar photovoltaic energy to make them more accessible to people. Through this, I hope many people will better understand renewable energy and actively incorporate it into their daily lives.
