Factsheets

Solar energy can be harnessed two primary ways: photovoltaics (PVs) are semiconductors that generate electricity directly from sunlight, while solar thermal technologies use sunlight to heat water for domestic uses, to warm buildings, or heat fluids to drive electricity-generating turbines. Solar technology generated 5% of U.S. electricity in 2024.¹ 

Solar Resources and Potential

Annual Average Solar Radiation in the U.S.³

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• On average, 173,000 TW of solar radiation continuously strike the Earth,⁴ while global electricity demand averages 3.1 TW.⁵
• Electricity demand peaks at different times than PV generation, creating energy surpluses and deficits. Energy storage and demand management help match PV generation with demand.⁶
• PV conversion efficiency measures the percentage of solar energy converted to electricity.⁷ While most available solar panels achieve ~20% efficiency,⁸ researchers have developed modules approaching 50%.² The highest lab efficiencies are 40.6% for hybrid four-junction cells and 35.9-38.9% for gallium arsenide (GaAs) III-V concentrating modules.⁹
• Net energy ratio compares an energy system’s life cycle energy output to its life cycle primary energy input. One study found that amorphous silicon PVs generate 3-6 times more energy than is required to produce them.¹⁰

PV Technology and Impacts

PV cells

• PV cells are made of semiconductor materials that free electrons when struck by light, producing electrical current. Various materials can be used, including silicon, copper indium gallium diselenide (CIGS), cadmium telluride (CdTe), perovskites, and organic compounds (OPV).¹¹ PV cells also include electrical contacts that allow electrons to flow to the load and surface coatings that reduce reflection.¹¹
• Most PV cells are small, rectangular units producing a few watts of direct current (DC) electricity.¹¹

PV Modules and Balance of System (BOS)

• PV modules typically comprise 60-72 cells arranged in a rectangular grid, laminated between transparent front and structural back surfaces. They usually have metal frames and weigh 34-62 lbs.¹²
• A PV array is a group of electrically connected modules fastened to a rigid structure.¹³
• BOS components include all necessary elements beyond PV panels: connecting wires, junction boxes, mounting hardware, and power electronics that manage array output.¹³
• An inverter is a power electronic device that converts PV-generated DC electricity to alternating current (AC).¹³ Higher inverter loading ratio (ILR)—the ratio of DC module capacity to AC inverter capacity—increases inverter utilization, reducing costs per kWh of AC output.¹⁴
• Charge controllers are power electronic devices that manage energy storage in batteries (which are also BOS components).¹³
• Crystalline silicon (c-Si) is the dominant module technology globally and in the U.S. Commercialized alternatives include cadmium telluride (CdTe) and copper indium-(gallium)-diselenide (CIGS/CIS) thin-film modules.¹⁵
• Cost efficiency (cost per watt) matters more than conversion efficiency for most applications. In the U.S., c-Si modules had a minimum sustainable price (MSP) of $0.25/W in 2020, while III-V technology had an MSP of $77/W, keeping it in niche markets like space and terrestrial concentrator applications.¹⁵
• Bifacial PV modules capture sunlight on both sides, increasing energy production up to 15% over single-sided modules.¹⁶ The global market share of bifacial PV modules was 12% in 2020, and is projected to reach 30% by 2030.¹⁷
• Tracking systems that can follow the sun through the day have become increasingly attractive for ground-mounted systems, despite upfront cost premiums. Tracking systems increase energy production 15-35% (single-axis) to 25-50% (dual-axis) over fixed-tilt systems.¹⁶ In 2023, 96% of new U.S. capacity used tracking.¹⁸
• Building Integrated PV (BIPV), such as solar shingles, replaces building materials and improves PV aesthetics.¹⁹

PV Installation, Manufacturing, and Cost

• In 2024, global PV power capacity grew by 597 GW to reach 2.2 TW. Top installers were China (328 GW), the U.S. (48 GW), and India (30 GW).²¹
• New PV installations grew 33%, down from 85% in 2023, and accounted for 81% of all new renewable capacity globally.²¹ Solar provided 46% of renewable electricity generation and 7% of global electricity production in 2024,²¹ up from 5.5% in 2023.²² Global solar capacity is set to exceed 7 TW by 2030.²¹
• U.S. average power purchase agreement (PPA) prices fell 88% from 2009 to 2019, reaching 2.3¢/kWh, then rose to 3.5¢/kWh in 2023.¹⁸ 

• In 2011, the U.S. DOE announced the SunShot Initiative with a 2030 goal of reducing the cost of utility-scale solar energy to 3¢/kWh, cheaper than fossil-fuel electricity.²³
• Driven by lower capital costs and higher capacity factors, the average levelized cost of energy (LCOE) for utility-scale solar PV dropped by 80% since 2010 to 4.6¢/kWh in 2023.^18,24
• However, significant disruptions in global supply chains over the past three years resulted in a rise in LCOE,²² reaching 6.1¢/kWh in 2024 before falling to 5.8¢/kWh in 2025.²⁴
• Global solar investment is estimated to exceed $450B in 2025—13% of total energy investment—surpassing all other generation sources.²⁵
• In December 2023, there were 279,447 solar workers in the U.S., a rise of 5.9% (15,564 jobs) since 2022.²⁶

Environmental Impacts

• Designing for end-of-life could improve the current 10% recycling rate of PV modules.²⁷
• Although pollutants and toxic substances are emitted during PV manufacturing, life cycle emissions are low. Thin-film CdTe produces roughly 14 g CO₂e/kWh28—far below coal at 1,001 g CO₂e/kWh.²⁹
• PVs use significantly less water to generate electricity (26 gal/MWh) compared to non-renewables like coal (687 gal/MWh).³⁰

Solutions and Sustainable Actions

• The Inflation Reduction Act of 2022 provides a 30% Investment Tax Credit and Production Tax Credit of 2.75¢/kWh for qualified solar systems through 2027.^31,39
• Residential customers receive a 30% credit on qualified clean energy equipment, including rooftop solar and solar water heaters, installed through 2025.^32,39
• Check the DSIRE database or contact your state energy agency for more incentives on your solar installation.³³
• Those without access to roof space for PV panels can join community solar programs, which are local projects that share ownership and receive credit on their electricity bills.³⁴
• There are 41 states, plus D.C., have at least one community solar project online, with 5.8 GW installed cumulatively through the first half of 2023.³⁴
   

• See the Wind Energy Factsheet for renewable energy mechanisms including unbundled renewable energy certificates (RECs), community choice aggregation (CCAs), and power purchase agreements (PPAs). In 2022, 32% of market sales from these mechanisms were from solar.³⁶
• Solar REC (SREC) markets require electricity suppliers to purchase SRECs from in-state solar systems as part of their obligation under state Renewable Portfolio Standards.³⁷ As of 2025, DC, DE, IL, MD, OH, and PA provide SREC programs.³⁸