1 Introduction

PV systems are found in three marketing areas: residential rooftop, commercial rooftop, and ground-mounted utility-scale systems (solar parks). A decade ago, rooftop systems accounted for 60% of the global installations, changing rapidly toward utility-scale systems. Residential systems are normally around 10 kW, while commercial systems reach a megawatt-scale. The utility-scale solar PV power plants are in the range of 100–500 MW and moving to the 1 GW capacity; they are becoming more common, especially in hot regions of the world.

The largest solar farms already have nearly 2 GW (2,000 MW) of generating capacity, with plans to extend to 5 GW. However, this electricity output is provided by numerous – frequently dozens – of individual solar plants, each with a capacity of 10 to 250 MW, as outlined below.

China and the U.S. are the leading nations pulling ahead in the sector, which jointly account for two-thirds of all solar power growth worldwide. Solar energy capacity has increased by approximately 70% over the last seven years, rising to 773 GW in 2020. But where are the largest solar power plants? Here, we profile the most prominent operational solar power plants in the world based on installed capacity.

2 The Biggest Solar Power Plants In The World

2.1 Topaz Solar Farm and Desert Sunlight Solar Farm, US

The Topaz solar farm is located northwest of the Carrisa Plains in San Luis Obispo County, California. The 550 MW plant was built up by First Solar and later acquired by BHE Renewables. Commissioned in 2014, the project spans over an area of 1,900 hectares and is equipped with more than eight million PV modules. Topaz supplies electricity to roughly 180,000 households in the Golden State. The US$2.5 billion Topaz is 4,550 US$/kW of power and holds a 26.6% capacity factor [1].

Topaz was built on an unproductive agricultural land six miles from the Carrizo Plain national monument. The project site was chosen after extensive research on various potential locations in the state. Among them are the availability of solar resources, the proximity of Moro Bay to Midway transmission lines, land uses and environmental factors.

Figure 1. Aerial view of the Desert Sunlight Solar Farm. Source: “Chuckwalla Valley solar power project” by Anita363 is licensed under CC BY-NC 2.0.

The Desert Sunlight solar farm can be found at the Mojave Desert in Riverside County, California. Developed by First Solar, the facility is owned by GE Energy Financial Services, NextEra Energy Resources, and Sumitomo Corporation of America. Inaugurated in 2013, the power plant has eight million panels that generate enough power for 160,000 homes.

Desert Sunlight uses a more significant number of 8.8 million cadmium telluride modules thin film. These modules have smaller form factors, lower wattage, lower efficiency, lower cost than conventional (silicon) alternatives. They are mounted on fixed-tilt arrays and spread over a larger land area — Topaz has the same technology.

With these two solar farms, California became the first state to generate more than 5% of electricity from utility solar in 2015. California’s utility-scale solar fleet boom was largely down to its aggressive 33% renewable portfolio standard.

2.2 Solar Star Projects

It comprises two co-located projects, Solar Star 1 2, in the Kern and Los Angeles counties and California. The two have a combined capacity of 579 MW and comprise more than 1.7 million PV modules installed on 1,300 hectares of land [2]. Solar Star Projects were developed by SunPower Corp. and owned by BHE Renewables.

Completed in 2015, the projects now supply electricity to more than a quarter-million homes. They are equipped with the SunPower® Oasis® Power Plant technology, which sets the panels to track the sun during the day and expands energy capture by up to 25%. Solar Star project uses c-Si modules. The projected O&M costs for Solar Star were consistent with the Public Service Company of New Mexico (PNM)’s $21/WAC-year estimate of annual O&M costs (which, in addition to O&M contract costs, also include costs associated with vegetation and animal management, vandalism, and other property damage) for 40 MWAC (split into two 20- MWAC projects).

2.3 Kamuthi Solar Power Station, India

The Kamuthi solar facility in Tamil Nadu, India’s southernmost state, has a total generation capacity of 648 MW. Covering about ten km² and of 2.5 million solar panels, the power plant is estimated to supply enough energy for 750,000 people. Kamuthi was completed in 2016 at the cost of approximately $680 million, and it was built in only eight months by a workforce of 8,500 people.

The solar project included the erection of 38,000 foundations and utilized 6,000 kilometers of cables, 576 inverters, and 154 transformers [3]. The solar modules are cleaned every day by a robotic system charged by its photovoltaic converter. The power generated by the plant is evacuated to the 400kV Kamuthi substation run by Tantransco and distributed to approximately 265,000 homes.

With this plant, India became one of only a handful of countries to generate more than 10 GW of solar power. India attained the third spot in the list of solar power producers. Kamuthi generates a massive amount of energy, but it’s only a first step for India’s solar plans. The country has set the resounding goal of powering 60 million homes with solar power by 2022, and there’s still a long way to go.

2.4 Enel Villanueva PV Plant, Mexico

By the time of commissioning, the Villanueva photovoltaic power plant was the biggest solar project in the world outside China and India. It comprises more than 2.5 million PV panels installed across 2,400 hectares in a semi-arid region of the Mexican state of Coahuila. The 828 MW facility became fully operational in September 2018 and can generate more than 2,000 GWh a year [4].

The Enel Group invested nearly $710 million in the construction of Villanueva. Although the plant’s original capacity was 754 MW, it was later leveraged to 828 MW following a 10% extension option appended to the energy sales contracts. A unique pilot program deployed by Enel used automation and digital technologies for the construction. The program included GPS-controlled machines for removing the earth, drones for conducting 3D topography, and robots for automatic installation of panels.

The panels are calculated to turn in tandem with the sun, like a field of metallic sunflowers; the whole project is part of Mexico’s push to generate 35 percent of its electricity from renewable sources by 2024.

2.5 Longyangxia Dam Solar Park, China

With a capacity of 850 MW, sufficient to power 200,000 households, this PV plant sits on the Tibetan Plateau and spans 27km². The approximately four million solar panels and auxiliary infrastructure are operated by State Power Investment Corporation, one of China’s top power generators. Phase one of Longyangxia was completed in 2013, while phase two was accomplished in 2015, with a total construction cost of approximately $920.84 million. The project was unfolded by Huanghe Hydropower Development and is integrated with the Longyangxia hydroelectric power station.

Figure 2. A satellite view of the Longyangxia Dam Solar Park. Source: https://www.engadget.com/2017-03-08-the-worlds-largest-solar-farm-from-space.html

Connecting FPV to existing transmission infrastructure may increase the utilization rates of transmission lines where additional transfer capacity exists. As high-quality hydropower and solar resources are often far from load centers, lengthy, dedicated transmission lines are usually required, for which hybrid systems may provide increased power generation (improved capacity factor for the hybrid system) over the stand-alone systems; the overall utilization and economics of dedicated lines may be enhanced. The Longyangxia solar PV-hydropower hybrid system also provides an example of reduced curtailment.

The 1,280-MW hydropower plant, built-in 1989, was complemented with a land-based 850-MW solar PV system with a 30-km interconnection line that allowed for a first-of-its-kind hybrid system operation. The hybrid operation permitted the elimination of all solar PV curtailment, and the system is now a firm, dispatchable generator [5]. During peak solar production hours, solar PV can provide power and hydropower resources can be conserved until solar resources are not available. Solar PV would help meet expected power production without curtailment in this configuration. The hydropower turbines could be ramped up or down as a complementary operation strategy. In pumped hydropower storage applications, excess solar PV generation can be used internally to replenish water resources (together with reservoir inflow) for use during other periods instead of curtailing.

2.6 Kurnool Ultra Mega Solar Park, India

Kurnool solar farm covers 22.99 km² in Andhra Pradesh. With a total generating capacity of 1,000 MW, the solar park was built with an investment of approximately $1 billion. It was the world’s largest solar power park at a single location when commissioning. Presently, Kurnool solar ultra-solar mega-park is the third-largest solar power in the world after Tengger Desert solar park (1,547 MW), China and Bhadla solar park (2,250 MW), India.

The project was implemented in several phases by Prayatna Developers (50 MW), Azure Power (100 MW), Greenko Group (500 MW), and SBG Cleantech Project (350 MW). Approximately four million solar panels were installed on-site, each with a capacity ranging between 315 W and 320 W. Kurnool generates more than eight million kWh of electricity on sunny days, enough to meet the district’s total electricity demand. The solar PV Park is located at latitude 15.6815220 N, longitude 78.2837490 E. The site receives average solar radiation of 5.5 to 6.0 kWh/m2. MNRE chose this site to construct its 1000 MW plant since it is a location where the solar panels can absorb solar radiation for the entire year.

The maximum total energy generation was detected in March, and the lowest total energy generation was observed in July [6]. The solar power plant works with a good performance ratio (PR) and capacity utilization factor (CUF).

The maximum PR value of 83.44% was observed in August, and the minimum PR value was 75.24% in  October. The annual average PR value is found to be 79.94%. The maximum CUF of 29.34% was found in March, and the minimum CUF found in July was 18.90%. The annual CUF of the plant is 24.65%. Comparisons between the performances of a fixed-tilt angle system and a single-axis tracking system have also been drawn. It has been found that a single-axis tracking control system gives better performance in terms of power generation. Power generation is improved by 20% in the single-axis tracking system.

2.7 Datong Solar Power Top Runner Base, Datong City, China

The Datong solar project is coming true in Shanxi province, China. The project is part of China’s National Energy Administration’s plans to advance solar projects in the region. This plant is a work in progress, but it’s already one of the most extensive solar generation facilities globally in terms of capacity — clocking in 1.07 GW so far. An extra 600 MW is currently under construction, and the long-term plan is for the total capacity to hit 3 GW. It includes the development of seven 100 MW projects, five 50 MW projects, and many smaller capacity projects.

Several companies, including Datong Coal Mine Group, China Three Gorges New Energy, Huadian Shanxi Energy, JinkoSolar Holding, Yingli Green Energy, Datong United Photovoltaics New Energy, China Guangdong Nuclear Solar Energy, and State Power Investment, are participating in the development of the solar power plants under the project.

2.8 Tengger, China

The Tengger solar park located in Ningxia dubbed the ‘Great Wall of Solar,’ covers 1,200 km2 of the Tengger desert, occupying 3.2% of the arid region. The 1,547 MW plant is owned by Zhongwei Power Supply Company and China National Grid. Construction started in 2012, and the power plant became operational in 2017. The solar park supplies green energy to 600,000 households.

2.9 Benban Solar Park, Egypt

The 1.8-gigawatt installation is the first utility-scale PV plant in Egypt, a nation blessed with some of the world’s best solar resources. The ambitious project is part of the national efforts to increase its generation capacity and incorporate more renewable sources into the mix [7].

Located about 650 kilometers south of Cairo, the Benban Solar Park is Africa’s largest solar farm. The project, owned by the New and Renewable Energy Authority [8], was completed in late 2019 at the cost of $4 billion. The Egyptian government adopted an economic model for which the sell-back price was higher than the purchase cost from the grid. The government offered a competitive price for producing electricity for the coming 25 years by using loans from the international finance corps.

2.10 Huanghe Hydropower Hainan Solar Park, China

This 2.2 GW solar park in the Qinghai Province, developed by state-owned utility company Huanghe Hydropower Development, went online in September 2020. The plan is for this farm’s capacity to reach a staggering 16 GW in the long run. The plant also comprises 202.8 MW/MWh of storage capacity.

2.11 Bhadla Solar Park, India

With a final capacity of 2.25 GW across 5,600 square kilometers, Bhadla Solar Park in India is the largest solar power facility in the world to date. Located in the village of Bhadla in Rajasthan, this project is the top solar farm in the world in terms of capacity.

This case is relevant because it shows evidence of today’s ultralow cost PV power generated by utility-scale solar parks. Construction of the solar park took place in four separate auctions. In late 2017, the Bhadla Phase III 500 MW auction ended with record low tariffs of INR 2.44 ($0.037) per kWh to develop 200 MW, and another company won a bid to develop another 300 MW of grid-connected solar power with a tariff of INR 2.45 ($0.038) [9].

Loss of arable land to massive PV systems needs to be carefully avoided to not interfere with the growth of its agrarian sector. In its place, the government is rightly favoring the installation of multi GW PV stations in the country’s desert areas of country, primarily located in the north, such as that hosting the Bhadla Solar Park and to its northwest (the Thar desert) in areas such as Thar (Rajasthan), Rann of Kutch (Gujarat), Ladakh (Jammu and Kashmir), and Lahul and Spiti Valley (Himachal Pradesh) with a total geographical area of 330 000 km2. This, in its turn, requires the deployment of long-distance transmission lines and substations connecting the power stations where energy is produced with cities and rural areas where it is consumed.

Figure 3. A view of the huge Bhadla Park in the Rajasthan Desert. Source: https://www.youtube.com/watch?v=8m0IAy8jjLY

3 References

[1] Boretti, A., & Castelletto, S. (2020). Trends in performance factors of large photovoltaic solar plants. Journal of Energy Storage, 30, 101506. doi:10.1016/j.est.2020.101506

[2] https://www.power-technology.com/features/the-worlds-biggest-solar-power-plants/

[3] https://www.popularmechanics.com/science/green-tech/a24063/worlds-largest-solar-plant-india/

[4] https://www.gob.mx/sener/articulos/se-inaugura-la-planta-solar-villanueva-en-coahuila

[5] Lee, N., Grunwald, U., Rosenlieb, E., Mirletz, H., Aznar, A., Spencer, R., & Cox, S. (2020). Hybrid floating solar photovoltaics-hydropower systems: Benefits and global assessment of technical potential. Renewable Energy. doi:10.1016/j.renene.2020.08.080

[6] Boddapati, V., & Daniel, S. A. (2020). Performance analysis and investigations of grid-connected Solar Power Park in Kurnool, South India. Energy for Sustainable Development, 55, 161–169. doi:10.1016/j.esd.2020.02.001

[7] https://ieeexplore.ieee.org/abstract/document/8889899

[8] http://nrea.gov.eg/test/en/Home

[9] Asian Development Bank, Rajasthan Renewable Energy Transmission Investment Program, Manila: 2019, www.adb.org/sites/default/ files/project-documents/45224/45224-002-data-en.pdf (accessed: November 2021).