Lifecycle Impacts: Mining, Manufacturing, Recycling and Emissions per kWh

Wind turbines and solar panels burn no fuel, but they do not come from nowhere. Steel is smelted, silicon is purified in furnaces, copper and lithium are mined, concrete is poured, trucks drive. A fair comparison counts all of it, from the mine to the landfill or recycler, and divides by every kilowatt-hour the equipment ever makes. That is a lifecycle assessment.

What a lifecycle number counts

The answer is expressed in grams of CO2-equivalent per kilowatt-hour (g CO2e/kWh). "Equivalent" means methane and other gases are converted to CO2's warming effect. "Per kWh" means total lifetime emissions divided by total lifetime output, so assumptions about lifetime and capacity factor matter. A panel that lasts 30 years in Arizona has a lower number than the same panel lasting 25 years in Seattle.

The comparison table

The IPCC's Fifth Assessment Report (2014) compiled published lifecycle studies in Annex III, Table A.III.2. NREL's harmonization project reworked hundreds of studies to common assumptions and published an updated summary in 2021. NREL found harmonization did not change any technology's median much, but narrowed the spread.

Read it slowly. The big gap is between combustion and everything else: coal and gas sit in the hundreds, while wind, solar, nuclear, geothermal and most hydro sit in the tens. Among the low-carbon group, differences of 10 or 30 grams are real but small next to the gap with fossil fuels. The biomass numbers differ a lot between the two sources because they cover different fuels and accounting choices (IPCC's line is for dedicated energy crops and includes some land effects). The NREL column is taken from a chart of NREL's medians reproduced in an open geology textbook (linked in sources). Cite the NREL fact sheet itself when you use these numbers in testimony, a public comment or online.

Coal:        10,000 x 820 g = 8,200,000 g = 8.2 metric tons CO2e
Gas CC:      10,000 x 490 g = 4.9 metric tons
Utility PV:  10,000 x 48 g  = 0.48 metric tons
Nuclear:     10,000 x 12 g  = 0.12 metric tons
Wind:        10,000 x 11 g  = 0.11 metric tons

Mining and minerals

Low-carbon power trades fuel for materials. The International Energy Agency's 2021 report on critical minerals found that a typical electric car needs six times the mineral inputs of a conventional car, and an onshore wind plant needs nine times the mineral resources of a gas-fired plant of the same capacity. Solar needs silicon, silver, copper and aluminum. Batteries need lithium, graphite and, for nickel-based chemistries, nickel and cobalt. Offshore wind and many turbine generators use rare earth magnets.

The bigger issue may be refining, not mining. IEA's 2025 outlook found that across 19 of 20 key energy minerals, China is the dominant refiner, with an average share around 70 percent. The top three refining countries' average share for key minerals rose from about 82 percent in 2020 to 86 percent in 2024. Lithium demand grew nearly 30 percent in 2024 alone. Those concentrations are why the 2025 federal tax law added "foreign entity of concern" restrictions, and why Lazard reported battery costs rising in 2026 as supply chains shifted.

Mining's local effects are concrete: water use and contamination, tailings dams, dust, labor conditions in some supplying countries, and land disputes with Indigenous communities. Fossil fuels have their own extraction burdens, from coal mine reclamation to methane leaks from gas wells. A fair comparison weighs extraction against extraction.

Manufacturing

Most of a solar panel's lifecycle emissions come from purifying silicon, which takes a lot of heat and electricity. Where that happens matters: a panel made with coal-heavy power carries more embodied carbon than one made on a hydro-heavy grid. That is one reason ranges in the table are wide. For wind, steel and concrete for towers and foundations dominate. For batteries, cell manufacturing and the cathode materials dominate. In each case, embodied emissions are typically repaid by clean output within the first few years of a 20- to 35-year life, though the exact payback depends on the grid the plant displaces.

End of life

Solar panels

EPA notes glass is about 75 percent of a panel's weight and is readily recycled, as are aluminum frames and copper wiring. The hard parts are the bonded layers: cells laminated in polymers. EPA says panel recycling "is not yet happening on a large scale" in the U.S. Some panels contain lead in solder, and some thin-film panels contain cadmium, so disposal rules matter. One U.S. thin-film manufacturer runs its own recycling. IRENA, cited by EPA, projects recoverable materials from retired panels worldwide worth about $450 million by 2030.

Turbine blades

Towers and nacelles are mostly steel and copper and get recycled. Blades are fiberglass or carbon fiber in resin, built to be tough, which makes them hard to grind up. Many have gone to landfills; some are shredded into cement kiln fuel and feedstock. Newer recyclable resins exist but are not yet the norm.

Batteries

Lithium-ion batteries contain valuable metals, which makes recycling worthwhile, especially for nickel and cobalt chemistries. IEA reports two-thirds of global battery recycling capacity growth since 2020 has been in China. Damaged batteries are harder: after the January 2025 Moss Landing fire, EPA's cleanup sent recyclable modules off site, while researchers found high levels of nickel, cobalt and manganese in nearby soil. Accidents are part of end of life too.