What Is Utility-Scale Solar?
When people think about solar energy, they often think of rooftop solar panels on a house. However, the residential solar energy market is only a small segment of the total installed solar capacity. According to the Solar Energy Industries Association (SEIA), there are over 37,000 megawatts of utility-scale solar energy projects in operation in the United States, with an additional 112,000 megawatts under development.
In fact, utility-scale solar is the largest segment in terms of installed solar energy capacity, followed by commercial solar, then residential solar. Finally, off-grid solar is just a tiny sliver of the total market. The significant players in utility-scale solar include China, the United States, Europe, India, Brazil, and Japan.
How Does Utility-Scale Solar Work?
Although there is no widely accepted definition of what makes a solar installation “utility-scale,” certain attributes set these solar farms apart from distributed generation, where the power is consumed at or near where it is produced.
Utility-scale solar farms differ because of the project size and that the energy is sold to wholesale utility buyers under power purchase agreements (PPAs), instead of to end users. These solar energy plants supply power at a fixed price, even during times of peak energy demand.
Increasingly, utility-scale solar plants are paired with battery energy storage systems (BESS) because renewable energy is an intermittent power source. Battery banks help utility companies meet peak energy demand with clean energy, which often occurs on summer evenings.
How Much Energy Does The Grid Pull From Utility-Scale Solar Producers?
Roughly 4,116 billion kilowatt-hours (kWh) of electricity were generated at utility-scale power plants in the United States in 2021, according to the United States Energy Information Administration (EIA). Of that, about 61% was from fossil fuels, mainly natural gas and coal, and nuclear power plants generated nearly19%.
Renewables comprised 20% of the total, with wind energy accounting for 9.2%, hydropower at 6.3%, and solar energy accounting for 2.8% or 115 billion kilowatt hours. Of that, photovoltaic solar generated 112 billion kilowatt hours, and solar thermal power plants produced 3 billion kilowatt hours.
Although historically, wind energy capacity increased more quickly than solar energy, this trend has shifted. According to the EIA, the anticipated electricity generation capacity additions for 2022 put solar energy at 49% and wind power at 11%. If this trend continues, solar energy generation will increase at a faster rate than new wind energy capacity.
Types Of Grid Scale Solar Projects
There are two primary solar power technologies in use at utility-scale solar plants.
Photovoltaic (PV) Solar Farms
These solar modules use sunlight to generate a current of electricity and are the same technology commonly used for residential and commercial solar PV systems. The solar cells contain a semiconductor material, typically silicon, and produce direct current (DC) voltage. Then, an inverter converts the power to alternating current (AC).
The greater the intensity of the sunlight, the greater the flow of electricity. The PV panels on the market today are commonly between 16% and 23% efficient; solar panel efficiency has increased significantly over the last couple of decades.
Concentrated Solar Power Plants
This technology uses mirrors to concentrate the sun's heat to drive steam turbines or engines, producing electricity. In addition, plant operators can store the thermal energy generated from concentrated solar power (CSP) plants to generate electricity later. There are several types of CSP technology in use in the United States, including parabolic trough, compact linear Fresnel reflector, power tower, and dish-engine.
Challenges For Utility Solar
Although utility-scale solar is growing significantly, there are project development hurdles to content with.
Permitting For Utility-Scale Solar Projects
Unfortunately, permitting issues can delay projects or even stop them from progressing. Congested interconnection queues can slow renewable energy project development because interconnection studies can be time-consuming and expensive. Interconnection timelines and costs are among the biggest hurdles to rapid utility-scale solar growth.
Transmission Capacity Expansion
Developers often locate utility-scale renewable energy projects far from load centers, so they require transmission capacity expansion to reach electricity markets. Therefore, generation interconnection requests often require transmission network upgrades.
Solar developers often foot part of the bill for needed improvements to the electricity grid, despite many of these upgrades creating system-wide benefits. These costs drive up the cost of solar electricity and create uncertainty as they can be challenging to anticipate.
Supply Chain Issues
Equipment shortages and bottlenecks have impacted the solar market, causing some projects to be delayed or even canceled. For example, solar panels from China are subject to antidumping laws and import tariffs. A recent investigation into numerous solar manufacturers in Southeast Asia, including Jinko Solar, Hanhwa Q Cells, Canadian Solar, and Trina Solar, has shown slowed imports to the United States. In addition, shipping bottlenecks and supply chain shortages have also been problematic.
Solar power plants require land. Unfortunately, large plots of land are often most available and affordable in rural areas far from load and population centers. Solar developers often lease land from landowners for the project's lifespan or, in some cases, they purchase the land.
Utility-Scale Solar Installations Are Essential
As concern about greenhouse gas emissions and climate change continues to rise, utility-scale PV plants provide a solution. As the installed capacity of solar photovoltaics increases, the demand for fossil fuel power plants decreases. In addition, battery storage systems at solar plants enable solar power to meet peak energy demand, even when the sun isn’t shining.
Utility-scale solar comes with it’s own permit and engineering nuances and challenges – GreenLancer has a network of designers and engineers who specialize in AHJs across the country to navigate the process with simplicity.