Solar Energy

Solar energy is the process by which electromagnetic radiation generated by thermonuclear fusion reactions in the Sun reaches Earth and is converted into heat and electrical energy. The Sun produces approximately 3.86×10²⁶ watts of power per second, of which about 1.74×10¹⁷ watts reaches Earth’s atmosphere. This amount corresponds to roughly 15,000 times the world’s annual energy demand.

Solar radiation spans a broad electromagnetic spectrum including visible, ultraviolet (UV), and infrared (IR) regions. While the irradiance outside the atmosphere averages 1,370 W/m², the net irradiance reaching the Earth’s surface is approximately 1,000 W/m² on average due to reflection, absorption, and refraction in the atmosphere, with variations depending on geographic location.

Energy Conversion Technologies

Solar energy is primarily converted in two ways: direct electricity generation through photovoltaic (PV) systems and heat production through thermal systems. Photovoltaic cells used in the energy conversion process are made of semiconductor materials that directly transform the energy of incoming photons into electrical current. Since no moving parts are required during this conversion, maintenance costs are low and the system has a long operational lifespan. In thermal collectors, incoming solar radiation is converted into thermal energy using liquid- or air-based systems.

Solar energy can be utilized in numerous applications including heating, electricity generation, agricultural drying, and desalination of seawater. All these physical and technical characteristics make solar energy an attractive energy alternative at both individual and industrial scales. Increasing efficiency levels due to technological advancements indicate that solar energy will play a more widespread role in future energy systems.

Solar Energy Developments Worldwide

Global interest in solar energy has increased rapidly in recent years, driven primarily by environmental concerns related to fossil fuels and energy security issues. Investment in solar energy accelerated from the 1990s onward, and with cost reductions in photovoltaic technologies during the 2000s, large-scale installations became widespread globally.

China is the global leader in both solar panel production and installed capacity. The country has enhanced its global influence in this sector through vast solar farms built in extensive desert areas and export-oriented production capacity. A significant portion of China’s total installed capacity has been developed through state-supported programs.

Germany has drawn attention for its feed-in tariff system promoting the widespread adoption of solar energy. Under this system, individual producers are guaranteed fixed prices for electricity fed into the national grid. This has led to widespread residential solar panel installations and an increased share of renewable energy in the country’s energy mix.

The United States has made substantial solar energy investments, particularly in southern states. Abundant land availability, incentive programs, and private sector investments have rapidly increased installed capacity. Additionally, R&D efforts continue to improve photovoltaic cell efficiency.

International energy agencies have issued policy documents advocating for an increased share of solar energy in global electricity production. Financial incentives for renewable energy investments are creating favorable conditions for the further expansion of solar energy in the coming years.

All these developments demonstrate that solar energy is no longer merely an alternative but has become one of the key actors in energy policy. In this context, technological advancements and cost advantages are positioning solar energy as the primary energy source of the future.

International Organizations’ Solar Energy Policies

Global policies on solar energy are largely guided by two main institutional actors: the International Energy Agency (IEA) and the International Renewable Energy Agency (IRENA). These organizations develop comprehensive scenarios and strategic plans aimed at achieving low-carbon energy transitions.

The IEA’s “Net Zero by 2050” scenario forecasts that solar energy will account for one-third of global electricity production by 2050. Under this scenario, annual solar energy investments must exceed one trillion dollars. Thus, solar energy plays a central role in combating climate change.

IRENA publishes guidelines covering the necessary infrastructure, regulations, and financial models for expanding solar energy and supports technology transfer-based collaborations. This agency aims to achieve at least 5 terawatts of global solar energy capacity by 2030.

The policies proposed by these organizations emphasize affordable credit mechanisms, capacity development programs, and incentives for grid integration. These measures aim to facilitate easier access to solar energy for developing countries.

In addition, under international agreements, carbon emission trading systems grant favorable treatment to solar energy investments due to their environmental benefits. This encourages private sector investment to shift toward renewable energy sources. Viewed in this context, the international organizations’ vision for solar energy represents a comprehensive transformation process encompassing not only technical but also socio-economic and environmental dimensions.

Türkiye’s Solar Energy Potential

Türkiye is among countries with high solar energy potential due to its geographic location. The average annual sunshine duration is approximately 2,640 hours, and the total annual radiation amounts to 1,527 kWh/m². These figures indicate that Türkiye holds an advantageous position compared to European countries. The Southeastern Anatolia, Mediterranean, and Central Anatolia regions have particularly high radiation densities and are considered priority areas for investment.

Effective utilization of solar energy potential is strategically important for balancing Türkiye’s energy structure, which is heavily dependent on imports. Fossil fuel imports constitute a large portion of Türkiye’s total energy consumption. Therefore, investments in solar energy are crucial for enhancing energy supply security and reducing the trade deficit.

Systematic efforts on solar energy in Türkiye began in the 1970s, and residential solar collectors became widespread in the 1980s. Investment in electricity generation based on solar energy accelerated from the 2010s onward. The Renewable Energy Resources Support Mechanism (YEKDEM), implemented in 2013, increased private sector interest in this field, leading to significant growth in both licensed and unlicensed solar power plants.

As of 2023, Türkiye’s installed solar energy capacity has exceeded 10 GW. However, it is estimated that only about 20% of its potential has been utilized so far. This highlights the need to improve technical infrastructure and simplify regulatory frameworks. Additionally, increasing domestic production rates is a strategic objective alongside incentivizing solar energy investments.

Türkiye is listed in international energy organization reports among countries that have not yet fully assessed their solar potential. Despite its high potential, Türkiye’s mid-tier position in global rankings underscores the importance of policy and planning processes. Developing domestic technology, enhancing grid integration, and supporting systems located close to consumption points are priorities in this context.

Next-Generation Solar Energy Technologies

Traditional solar energy technologies are primarily based on silicon photovoltaic panels and flat-plate solar collectors. However, recent advances in nanotechnology, materials science, and optical engineering have opened the way for significant innovations in solar energy technologies. Research has intensified on new materials aimed at improving efficiency and reducing costs.

Perovskite-based solar cells attract attention due to their low production cost and high light absorption capacity. Laboratory efficiency levels for these cells have exceeded 25%. Additionally, their production can be carried out at low temperatures using simple methods, offering advantages for transitioning to mass production. However, research and development activities continue to address issues related to stability and toxicity.

Organic photovoltaic cells are ideal for diverse applications such as wearable technologies and building facades due to their flexible structure. These cells can be manufactured in transparent forms, allowing aesthetic integration into glass surfaces. Their lightweight nature also makes them suitable for portable energy solutions. Academic research on these technologies is ongoing in Türkiye, with pilot applications being supported.

Concentrated Solar Power (CSP) systems use mirrors and lenses to concentrate sunlight onto a focal point to generate high-temperature heat. These systems convert thermal energy into electricity via steam turbines and, thanks to their thermal energy storage capabilities, enable electricity generation during nighttime. This feature plays a crucial role in enhancing the continuity of solar energy supply.

Future-oriented technologies include “solar windows,” “space-based solar energy systems,” “quantum dot PV cells,” and “biological PV systems.” In these fields, increasing R&D investment and processes such as patent generation and technology transfer are of great importance. In Türkiye, various projects in these areas are being conducted under the leadership of TÜBİTAK and universities.

Environmental Impacts of Solar Energy

Solar energy is among the renewable energy sources with the lowest environmental impacts. Electricity generation produces no greenhouse gas emissions, providing a significant advantage in combating global warming and climate change. Solar panels do not emit pollutants such as carbon, sulfur, or nitrogen compounds during operation. This improves air quality and contributes to public health.

Some chemicals and energy-intensive processes are used in panel manufacturing. However, lifecycle analyses show that solar panels typically recover the environmental impacts of their production within 1 to 3 years and provide clean energy for 25 years. Thus, the environmental benefits far outweigh the initial production-related harms.

The installation of solar power plants requires large land areas, which can exert pressure on ecosystems. Installations in natural areas may pose risks to biodiversity. Therefore, environmental impact assessment (EIA) reports must be carefully prepared when selecting locations. Rooftop installations largely eliminate this issue.

Waste generated at the end of panel life is also an important environmental concern. However, a large portion of this waste is recyclable. Advanced countries have established solar panel recycling facilities and developed legal frameworks to regulate this process. Similar initiatives must be launched in Türkiye to ensure sectoral sustainability.

The use of solar energy also reduces water consumption in electricity generation. Unlike thermal power plants, PV systems can generate electricity without consuming water. This is a significant advantage for preserving water resources. In regions vulnerable to drought, expanding solar energy systems directly contributes to the protection of natural resources.