The 5 Main Types of Renewable Energy Principles, Costs, Efficiency, and Home Use Guide

The five major types of modern renewable energy used primarily for electricity generation include: Hydropower, Wind Energy, Solar Energy, Bioenergy (biomass energy/biofuels), and Geothermal Energy.

In 2023, renewable energy accounted for nearly 30% of global electricity generation. Among them, hydropower made up 47%, wind power 26%, solar energy 18%, bioenergy 8%, and geothermal energy 1%.

China accounted for 32% of global renewable electricity, followed by the United States (11%), Brazil (7.0%), Canada (4.7%), and India (4.3%).

By 2030, global renewable electricity generation is expected to reach 17,000 TWh (60 EJ), an increase of nearly 90% compared to 2023. By then, renewables will account for 46% of global electricity, with wind and solar PV together making up 30%.

This article provides an in-depth analysis of the power generation principles, global distribution, technological efficiency, cost levels, and future trends of these five renewable energy types, while also offering clear recommendations for urban and rural households in selecting suitable renewable energy systems.

Hydropower

As of 2023, hydropower accounted for 47% of global renewable electricity generation.

Hydropower is a method of generating electricity by harnessing the potential and kinetic energy of flowing water to drive turbines. Common types include dam-based hydropower, diversion hydropower, and tidal hydropower.

Hydropower is virtually carbon-free and produces minimal pollution during operation. However, the construction of large dams can cause ecological disruptions (such as interruption of fish migration and wetland submersion) and may lead to population displacement.

Installing a hydropower system at home requires a consistent and stable water source (with sufficient head and flow), and is subject to water regulation laws, making it highly impractical for most households.

In 2023, the cost range for “construction-to-commissioning” small and large-scale hydropower projects was between USD 2,820–18,700/kW, with larger projects typically incurring higher costs.

Power Generation Efficiency

Modern hydropower systems are highly efficient, with efficiencies reaching up to 90% or more. Compared to solar (about 20%) and wind energy (around 30%), hydropower is remarkably efficient.

Global Distribution and Future Growth of Hydropower

As of 2023, China held 29–31% of global hydropower capacity, generating 1,245–1,303 TWh, making it the world’s largest hydropower producer. It was followed by Brazil, Canada, and the United States—all of which are rich in water resources.

Although global hydropower capacity continues to increase, its growth rate has slowed. Projections indicate that growth in the 2020s will be nearly 25% slower than the expansion rate seen in the previous decade.

Wind Energy

As of 2023, wind energy accounted for approximately 28% of global renewable electricity generation. The principle involves using wind to rotate turbine blades, which through a gearbox increase rotational speed, thereby driving a generator to produce electricity.

Common types of wind farms include onshore and offshore wind farms. Onshore farms are usually located in flat or elevated open areas, while offshore farms are installed at sea where wind speeds are generally stronger and more stable.

Wind energy produces virtually no emissions during operation and is considered one of the cleanest energy sources. However, some concerns exist regarding visual impact, disruption of bird migration, and noise. Regarding noise, many misunderstand or dismiss it, but in reality, a wind farm operating at a distance of 750 to 1000 feet does not produce noise louder than a kitchen refrigerator or a relatively quiet room.

Commercial wind turbines range in power from small residential units of about 5 kW to large utility-scale turbines up to 5 MW. Small residential turbines cost just a few hundred pounds, whereas industrial turbines can cost millions. In 2023, the levelized cost of electricity (LCOE) for onshore wind was between USD 1,300–2,500/kW, depending on location and scale.

Wind turbines are generally applied in industrial settings; for residential use, small rooftop turbines are possible but depend on local planning policies and wind conditions.

Power Generation Efficiency

Current wind power technology allows generation to start at wind speeds of about 2.68 meters per second. Conversion efficiency typically ranges from 20% to 40%, which is significantly lower than hydropower but higher than solar energy.

Global Distribution and Future Growth of Wind Energy

According to data from the International Renewable Energy Agency (IRENA) and the Global Wind Energy Council (GWEC), as of 2023, China accounts for 39% of the world’s total installed wind capacity, possessing the largest onshore wind capacity globally and surpassing the UK in offshore wind capacity. Other major countries include the United States, Germany, and India.

It is forecasted that by 2030, the wind energy sector will achieve a compound annual growth rate (CAGR) of 8.8%, with global installed wind capacity increasing by 981 GW.

Solar Energy

As of 2023, solar energy accounted for approximately 15% of global renewable electricity generation. Due to rapidly declining costs, flexible deployment, and near-zero emissions during operation, solar energy has become the fastest-growing renewable energy technology.

The working principle of solar energy involves photons from sunlight exciting electrons in solar panels—primarily made of semiconductor materials like silicon—freeing electrons to flow directionally under an electric field, generating current that is converted by an inverter into alternating current for household or grid use.

Although manufacturing solar panels produces a carbon footprint, the clean electricity generated by each panel over its lifetime more than compensates for this.

Photovoltaic (PV) systems have become mainstream due to easy installation and falling component costs. In 2023, utility-scale PV systems averaged around USD 800–1,200 per kW, with residential systems costing slightly more.

Power Generation Efficiency

Commercial PV panels typically achieve 18%–22% efficiency, with high-efficiency products exceeding 25%, and some developers achieving nearly 40%. While efficiency is much lower than other renewables, solar energy’s convenience and low cost make it the preferred choice for residential users.

Global Distribution and Future Growth of Solar Energy

China leads both manufacturing and installation of solar panels, followed by the United States, Japan, Germany, and India. The International Energy Agency (IEA) predicts solar energy will become the world’s largest electricity source by 2050.

Between 2024 and 2030, solar PV is expected to account for 80% of global renewable capacity growth, driven by new large-scale solar farms and increased commercial and residential rooftop installations. According to the IEA, solar PV electricity generation will surpass hydropower by 2029, becoming the largest renewable energy source.

Geothermal Energy

Geothermal energy harnesses the Earth’s internal heat for electricity generation or heating. Wells are drilled to access underground hot water or steam, which drives turbines for power generation or is used for building heating.

Shallow geothermal ground-source heat pump systems operate without emitting dust, waste, or CO2 and do not require boilers, cooling towers, or fuel storage, making them environmentally friendly heating and cooling solutions currently available.

Although geothermal energy generates small amounts of air and water pollutants, its CO2 emissions are only about 1/35th of coal-fired power plants.

Developing geothermal energy requires extensive geological exploration and drilling, resulting in high upfront investment. Additionally, uneven distribution of geothermal resources and technical challenges increase costs. In 2023, the cost of ground-source heat pumps was USD 4,589, nearly USD 1,200 higher than in 2022.

Power Generation Efficiency

Geothermal power generation efficiency typically ranges from 10% to 20%, depending on temperature and technology.

Global Distribution and Future Growth of Solar Energy

Geothermal resources are mainly concentrated along tectonic plate boundaries such as the Pacific Ring of Fire and the Mediterranean–Himalayan geothermal belts. Leading countries in geothermal development include the United States, Indonesia, the Philippines, Turkey, and New Zealand.

Technological advances have opened new prospects for geothermal energy, potentially making it a preferred choice worldwide and among businesses. As technology improves and project costs decline, geothermal energy could meet up to 15% of global electricity demand growth by 2050.

Biomass Energy

Biomass energy comes from agricultural residues, wood, and organic waste, and can be used for heating, electricity generation, or biofuel production. If properly managed, biomass is considered carbon-neutral because the CO₂ released during combustion is absorbed by plants.

Shallow geothermal ground-source heat pump systems operate without emitting dust, waste, or CO2 and do not require boilers, cooling towers, or fuel storage, making them environmentally friendly heating and cooling solutions currently available.

From a cost perspective, biomass is not particularly cheap. In 2022, the global average installation cost was USD 2,162 per kW, only a few hundred dollars less than hydropower.

Biomass is also relatively costly in the US, where direct combustion is the most common method for heat generation from biomass. Installation costs for small biomass power plants range from USD 3,000 to 4,000 per kW.

Power Generation Efficiency

Co-firing biomass with other fuels achieves efficiencies up to 45%, making it the most cost-effective biomass power generation method.

By 2050, biomass’s share in electricity production could rise from the current 1.3% to about 3%–5% (IEA ETP, 2006), depending on assumptions.

Compared to the estimated total biomass potential (10% to 20% of primary energy supply by 2050), this electricity contribution is relatively small, but biomass is also valuable for heating and transport fuel production.

FAQs about Renewable Energy

What renewable energy systems can households install?

• Urban/Suburban residences: Solar photovoltaic (PV) systems, with optional ground-source heat pumps.
• Rural/Farm residences: PV systems or a combination of PV and biomass boilers.
• Plateau/Remote mountainous areas: Priority on PV systems, with hydropower as an option if conditions permit.

What is the largest renewable energy source?

Currently, hydropower is the largest renewable energy source worldwide, accounting for nearly 50% of global renewable electricity generation, with an efficiency exceeding 90%. Some organizations predict that by 2029, solar energy will surpass hydropower to become the world’s largest renewable energy source.

What is the significance of using renewable energy?

• Reduce carbon emissions and mitigate climate change.
• Ensure sustainable energy supply without reliance on fossil fuels.
• Enhance energy independence.
• Lower long-term operational costs.

Renewable energy is rapidly transforming the global energy landscape. Whether it is the highly efficient hydropower, the rapidly growing wind and solar energy, or the dispatchable biomass and geothermal energy, each technology has its strengths and challenges. This transformation is penetrating every aspect of life—from global to household levels, from policies to technologies.

For household users, selecting the appropriate renewable energy system can not only reduce long-term energy expenses but also contribute to environmental protection. The next decade is a critical window; seizing policy incentives, technological maturity, and cost reduction trends will be the best opportunity to move toward a low-carbon lifestyle.