The global climate crisis is pushing governments and businesses worldwide to focus on terms like “net-zero carbon” and “carbon neutrality.” As awareness of environmental protection increases, the development of the renewable energy industry is becoming crucial. Renewable energy not only reduces greenhouse gas emissions and reliance on fossil fuels but also drives a low-carbon economy.
In addition to aligning with international environmental trends, renewable energy can enhance a company’s social responsibility image, attracting more consumers and investors. This article will introduce what green energy is, its types, and the trends worth noting.
What is renewable energy?
Renewable energy refers to energy that can be harnessed and reused from natural sources like solar, wind, hydropower, and geothermal. This type of energy has minimal environmental impact during production and use, emitting little to no greenhouse gases and pollutants, making it a key tool in combating global warming.
Global renewable energy development
In 2021, global wind and solar power generation surpassed nuclear power for the first time. The International Energy Agency (IEA) noted in its 2022 report that the energy crisis caused by the Russia-Ukraine war has accelerated the growth of renewable energy. The report projects that global investment in green energy will continue to grow steadily in the coming decades, becoming one of the primary energy sources.
According to the International Energy Agency's report in 2022, the energy crisis caused by the Russian-Ukrainian war has accelerated renewable energy growth. (Photo: iStock)
Governments worldwide are supporting green energy through various policies. The European Union introduced the European Green Deal to increase the share of renewable energy by 2030. The United States passed the Inflation Reduction Act, offering tax breaks to the green energy sector. China launched its 13th Five-Year Plan for Energy Development, heavily promoting solar and wind energy.
Many companies are also actively transitioning to seize opportunities in emerging markets. Tesla, for example, is not only focused on electric vehicles but also on solar and energy storage, including products like the Powerwall for homes and the large-scale Megapack batteries. Tech giants like Google and Apple are striving to power their data centers with 100% green energy. Meanwhile, energy giants like BP and Shell are investing in wind and solar projects to reduce their dependence on fossil fuels.
Types of renewable energy
1. Solar
Solar panels can be installed on roofs or on the ground, as they require a larger area to collect electricity due to the low density of solar energy. (Photo: iStock)
Solar panels can be installed on rooftops or outdoor ground spaces. Due to the low energy density of sunlight, large areas are needed to collect sufficient solar power.
Advantages
- Low energy density: The energy produced per unit area is low, requiring large equipment to meet demand, which can consume significant land space.
- Intermittent power generation: Solar energy depends on sunlight and cannot generate power at night or during cloudy weather, necessitating the use of storage systems.
- High initial cost: Although operating costs are low, the initial installation cost of solar equipment remains high.
Disadvantages
- High accessibility: Solar energy is less geographically restricted and can generate power wherever there is sunlight, making it versatile for installation on rooftops, building walls, and more.
- Quiet operation: Solar energy systems operate silently, making them suitable for residential areas.
- Low maintenance costs: Once installed, solar energy systems require minimal maintenance, with only periodic cleaning needed.
2. Wind
Wind power generates electricity more efficiently than solar power, but at a higher initial investment cost. (Photo: iStock)
Wind power technology converts wind energy into electricity. Wind turbines use the wind to drive blades, converting mechanical energy into electrical energy. Wind power is environmentally friendly and is suitable for areas with abundant wind resources, such as coastal and inland regions.
Advantages
- High efficiency: Large wind turbines can achieve power generation efficiencies of 40-50%, significantly higher than solar energy’s 15-20%.
- Small footprint: Wind power equipment primarily consists of turbine towers, which have high land-use efficiency and can be integrated with agriculture and other uses.
- Flexibility: Wind turbines can adjust power output based on demand, complementing intermittent renewable energies like solar.
Disadvantages
- High initial investment and maintenance costs: Wind power requires significant initial investment, including the construction of turbines, installation, and infrastructure.
- Visual and noise impact: Onshore wind turbines can cause visual flicker and low-frequency noise, potentially disturbing nearby residents.
- Threat to wildlife: Spinning turbine blades can be hazardous to birds, and pile-driving can affect marine life.
3. Biomass
Biomass energy utilizes agricultural and industrial waste to generate electricity, promoting a circular economy, but the process can create carbon emissions. (Photo: iStock)
Biomass energy uses organic materials like crops, wood, and waste to generate renewable energy. Through processes like combustion, fermentation, or thermal conversion, these materials can produce electricity, heat, or fuel. Biomass energy not only reduces reliance on fossil fuels but also effectively manages waste.
Advantages
- Diverse forms: Biomass can be converted into gas (e.g., biogas), liquid (e.g., biodiesel and bioethanol), and solid fuels, meeting various energy needs.
- Waste reduction: Biomass energy utilizes agricultural and industrial waste, reducing environmental pollution and promoting a circular economy.
- Boosts agricultural economy: Growing energy crops provides farmers with additional income sources.
Disadvantages
- Competition for land and resources: Biomass feedstocks typically come from crops and forests, which may impact food security and biodiversity in resource-limited situations.
- Low conversion efficiency: Converting biomass to electricity or liquid fuels involves significant energy loss, leading to lower energy output than other renewables.
- Carbon emission concerns: Although considered carbon-neutral, biomass energy production can generate significant greenhouse gases during cultivation, collection, processing, and transport. Incomplete combustion may also release harmful gases.
4. Geothermal
Geothermal power is a baseload energy source, capable of generating stable power around the clock, but requires a higher level of technology. (Photo: PLN)
Geothermal power harnesses heat from within the Earth to generate electricity. This technology involves drilling to extract hot water or steam from underground. Geothermal resources are typically found in volcanic regions and offer a stable energy supply, providing 24-hour baseload power.
Advantages
- High stability: Unlike solar and wind energy, which are affected by sunlight and wind speed, geothermal power is unaffected by weather and can continuously operate during peak demand.
- Disaster resilience: Geothermal power plants are generally able to withstand natural disasters like earthquakes and tsunamis.
- Small land footprint: Geothermal power requires relatively little land, making it suitable for areas with limited land resources.
Disadvantages
- High upfront costs: Developing geothermal power requires extensive geological exploration and drilling, resulting in high initial investment costs and stringent technical requirements.
- Environmental impact: Geothermal wells may disrupt the landscape and affect ecosystems, while steam and hot water may contain toxic gases and heavy metals, potentially causing environmental pollution.
- Limited resource availability: Suitable areas for geothermal development are limited, and continuous supply levels are difficult to calculate precisely.
5. Hydro
Hydropower can quickly adjust its output to electricity demand; the downside is the amount of land needed to build dams. (Photo: iStock)
Hydropower technology uses the potential energy of flowing water to generate energy. It can be categorized into “conventional” and “pumped storage” systems. The former relies on the natural flow of rivers, while the latter uses the height difference between upper and lower reservoirs to generate power, releasing water during peak demand and pumping it back during low demand.
Advantages
- Rapid supply adjustment: Hydropower can quickly start and adjust power output, making it ideal for handling peak electricity demand.
- Low operating costs: Hydropower is a mature technology with highly automated operations, requiring minimal labor.
- High conversion efficiency: Hydropower conversion efficiency exceeds 90%, much higher than other renewables like solar and wind energy.
Disadvantages
- Environmental disruption: Building dams and reservoirs can flood large areas, disrupting local ecosystems and leading to biodiversity loss.
- Dependence on water resources: Hydropower relies on stable water supply, and droughts can reduce or even halt power generation.
- Large land requirements: Constructing dams requires substantial land, potentially flooding farmland and displacing residents, affecting local communities.
Taiwan’s renewable energy roadmap
The Taiwanese government has set a goal to establish the country as the “Asia-Pacific Green Energy Hub.” This strategy emphasizes not only diverse renewable energy sources but also the integration of energy-saving and storage systems. The latest target is to have renewable energy account for 20% of the energy mix by November 2026, with solar power reaching 20GW and wind power 6.5GW, with offshore wind power particularly attracting international investors.
Energy storage technology development is also a priority. According to Taiwan Power Company’s plans, cumulative storage capacity is expected to reach 1,000MW by 2025, enhancing the stability and resilience of the power system. According to the Taiwan Institute of Economic Research, investment in Taiwan’s energy storage startups surpassed solar energy for the first time in 2022, and the future of Taiwan’s green energy industry is expected to attract investors from various fields, including energy, technology, and finance.
Following renewable energy development: Joining the global energy revolution
Renewable energy is at the core of the global energy transition and is key to achieving sustainable development. As climate change intensifies, countries are investing significant resources in developing renewable energy technologies to reduce reliance on fossil fuels. The expansion of the green energy market is expected to bring more environmental benefits and economic opportunities.
