The Minerals in Solar Panels and Solar Batteries

If you’re looking into going solar, you’re likely trying to save money, have greater energy independence, or use clean energy at home. Investigating how silicon is mined, refined, and used in manufacturing home solar panels might not be a high priority. 

But all those savings renewable energy can deliver start with the minerals and raw materials used in panels and batteries. Here’s where those vital minerals begin.

The Minerals in Solar Panels

While solar panels use the nearly infinite power of the sun to create electricity, a variety of non-renewable minerals mined from the earth make up the physical components of these green power systems. In the 2020s, most solar panels contain a combination of the following minerals.

• Aluminum
• Cadmium
• Copper
• Gallium
• Indium
• Lead
• Molybdenum
• Nickel
• Silicon
• Silver
• Selenium
• Tellurium
• Tin
• Zinc

It’s a long list of materials, including some rare earth elements. However, some of these minerals are currently used only in laboratories, in thin-film solar panels, or as a part of various emerging solar technologies. We will focus on the minerals used in home solar panels.

Where Are the Minerals in Solar Panels Found?

For solar panels and solar storage, some of the minerals used in production are found in specific locations, whereas others are found in large quantities around the planet.

Aluminum

The most abundant metallic element in the earth’s crust, aluminum can be found in igneous rocks (solidified from lava or magma) around the planet in the form of bauxite ore. Ore is natural rock or sediment that contains one or more valuable minerals and metals. The leading aluminum mines are in Australia, Brazil, Guinea, Jamaica, and Vietnam.

Copper

Copper is a significant ingredient for building out cheap, renewable energy and home electrification, as its high conductivity is essential for electricity generation. Chile is the world's leading producer of copper, followed by Peru, China, the Democratic Republic of Congo, and the US.

Silicon

Silicon is the second-most abundant element in the earth's crust, after oxygen. The leading silicon miners worldwide include China, Russia, the US, and Norway.

Silver

Silver is found in electrum alloy, a naturally occurring alloy of gold and silver, with trace amounts of lead, copper, and zinc. As a result, most of the silver used in today's manufacturing industry is obtained when processing other ores. Mexico has the largest annual silver production, and other leading silver producers include Peru, Poland, Norway, Canada, the US, and Bolivia.

Zinc

Zinc is found in over 50 countries, with the leading producers being Canada, Australia, China, Peru, and the US Currently, Alaska’s Red Dog Mine is the largest zinc mine in the world.

Beyond these “big 5” minerals, there are also some rare earth minerals in solar panels that are found in various parts of the world:

• Selenium: Although selenium-rich ores exist, the selenium used in solar panel manufacturing is usually obtained as a copper byproduct. The element is primarily mined in Japan, Canada, Belgium, and the US.
• Gallium: While gallium isn’t present as a free element in the earth's crust, miners extract it from other minerals such as aluminum, zinc, bauxite, sphalerite, coal, and germanite.
• Nickel: One of the essential metals in our everyday lives, nickel is found in the largest quantities in Indonesia, followed by the Philippines, Russia, Canada, Australia, and Brazil.
• Indium: A sulfide substitute in base minerals such as stannite, sphalerite, chalcopyrite, and stannite, indium rarely occurs geologically, so miners recover it from lead and zinc byproducts. China is the leading indium producer, followed by South Korea, Japan, and Canada.
• Tellurium: Obtained as a copper processing byproduct, tellurium is mainly mined in Japan and China.

How the Minerals in Solar Panels are Mined and Refined

As global solar capacity continues to increase, proper resource management is important for the industry to maintain sustainability. For long-term success, miners and manufacturing plants will need to appropriately manage their source materials to avoid adverse environmental impacts.

Aluminum

Using a surface-based method called open-cut mining, aluminum is sourced from the earth principally as bauxite ore. Once dug up, the ore is crushed, dried, and cleaned before being sent out for shipping and processing.

Bauxite ore becomes aluminum using the four-part Beyer refining process: digestion, clarification, precipitation, and calcination. Here, the bauxite is refined into its alumina form and then smelted to create aluminum.

Copper

Copper is mined from open pits and crushed during extraction and production. The open-pit process involves digging stepped benches into the earth, using a boring machine to drill holes, and then detonating explosives within them.

After mining, the copper ore is processed by grinding it roughly to separate any waste material. The copper is then hauled to a plant or smelter for refining. Copper refining removes impurities, leaving the refiner with 99.9% pure copper, the highest grade of copper.

Silicon

Silica is another name for industrial sand and gravel that has a high silicon dioxide (SiO2) content and can be refined into silicon. Silica mining uses open pits or dredging with standard mining equipment. Apart from the temporary disturbance in the immediate area, the silicon mining process has a minimal environmental impact on surrounding areas.

Silica metal is made of silica dioxide and carbon materials, so its refining process separates the minerals from their surrounding impurities. When the raw materials are placed in a furnace heated to 4,000° F, melting allows the materials to form into solid silicon and carbon monoxide.

Refiners then treat the metal with oxygen while it is still in the molten state, removing calcium and aluminum impurities. After this process, the resulting product is 98.5%-99.9% pure silicon (with minimal traces of aluminum and calcium) and poured into pots for cooling.

Silver

About 80% of the world's silver is produced as a byproduct of other minerals such as gold, lead, zinc, copper, and uranium. The remaining percentage comes from mining activities using open-pit methods in which heavy machinery reaches mineral deposits near the earth's surface.

After extraction, silver ores are crushed, ground down, and then separated through floatation to achieve 30-40 times the mineral concentration than its natural state. Refiners then put the extracted silver through electrolysis (a technique that uses direct electric current to create a chemical reaction) to concentrate it further.

Zinc

Zinc is mined underground using various techniques that include creating a near-horizontal passageway in a mine (called a “drift”) along a vein of zinc. Miners use a drill to blast a drift, so they can remove the zinc ore before hoisting it on the surface for concentration. After mining, the zinc ore is roasted to remove sulfur impurities and then processed using electrolysis.

How Are Minerals Used in Solar Panels?

The primary minerals used to build solar panels are mined and processed to enhance the electrical conductivity and generation efficiency of new solar energy systems.

• Aluminum: Predominantly used as the casing for solar cells, aluminum creates the framework for most modern solar panels. It’s the perfect metal for the frame because it’s lightweight, conducts heat, is durable, and can be easily recycled for other uses.
• Copper: Thanks to high conductivity and durability, copper is essential in solar manufacturing to increase the efficiency and performance of solar panels.
• Silicon: Silicon is the primary mineral solar panels use to generate electricity. With crystalline semiconductivity and light-absorbing properties, silicon captures and converts sunlight into free electrons which create electricity within solar cells.
• Silver: Turned into a paste by solar manufacturers and loaded onto each silicon wafer, silver is primarily responsible for carrying new solar electricity from the panels to the point of use, or the battery storage system.
• Zinc: Used in solar panels to improve energy conversion, zinc is used in high-tech solar generation because of its enhanced efficiency.

Negative Environmental Impact of the Minerals in Solar Panels

Unfortunately, if the minerals used to create solar power systems are handled or used incorrectly, this can create a variety of negative environmental implications:

• Aluminum: When present in high concentrations, aluminum can be very toxic to freshwater aquatic animals. Easily recycled, over 75% of the aluminum that has ever been produced is still in use today. However, the mining and refining processes are very resource-intensive.
• Copper: If released into the environment during mining, copper attaches to organic matter, clay, soil, and sand. This causes its compounds to release free minerals into local water, air, and food, which can harm aquatic and land-based life, reducing survival, reproduction, and growth.
• Silicon: During mining, silica particles may accumulate on the leaves of nearby plants, interfering with photosynthesis and the respiration process.
• Silver: When silver is produced in large quantities, mercury emissions may be released into the water, air, and soil, resulting in local human health concerns and environmental damages.
• Zinc: If large amounts of zinc are released into the environment during processing, it can affect water resources, crops, and soils. In locations with heavy pollution, this can cause a variety of negative effects on human health.

The Minerals in Solar Batteries

While new technologies are constantly being explored, the majority of today’s solar batteries are lithium-ion batteries. There are lead-acid and saltwater batteries, too.

As the predominant technology used in new residential solar batteries, it is important to know lithium-ion batteries often contain a range of elements and minerals beyond their “lithium” namesake. This includes:

• Chromium
• Cobalt
• Graphite
• Manganese
• Vanadium

Where Are the Minerals in Solar Batteries Found?

Lithium

Lithium is the 33rd-most abundant element in nature. Today, Chile has the largest lithium reserves globally, followed by Australia, Argentina, and China.

Lead

Lead reserves are found in many different countries around the world. China is the leading producer, followed by Australia, Peru, the US, Mexico, and Russia.

How Are the Minerals in Solar Batteries Mined and Refined?

Lithium

Lithium is found in underground clay deposits, brine, mineral ore, geothermal water, and seawater. Miners begin by drilling a hole, which they use to pump brine to the surface. Once on the surface, the brine is left alone for months to allow evaporation to remove the water.

The remaining lithium is filtered and placed into another evaporation pool. This process can take from eight months to three years to obtain usable lithium.

Lead

The solar industry uses newly-mined and recycled lead resources. Lead mining involves extracting ores from underground by using highly mechanized methods, or open pits.

After extraction, lead is ground into fine particles, similar to table salt texture. It's put through a floatation process by mixing it with water, pine oil, and air bubbles to form an oil froth. The lead ore floats on the froth, and the foam is skimmed and filtered to remove the water. Then, the powder is heated at over 2,500°F to remove impurities before being converted into molten lead.

How Are Minerals Used in Solar Batteries?

Let’s take a more detailed look at the three main solar energy storage systems currently being used in residential applications, and their primary solar battery materials:

Lithium-ion

The most common option for storing excess solar energy, lithium-ion batteries require less maintenance, last longer, are more efficient, and have higher energy density than lead-acid batteries. That’s why you see lithium-ion batteries powering electric vehicles as well as powering homes.

Lead-acid

Lead-acid batteries contain a mixture of sulfuric acid and water (electrolyte), a lead metal plate with a negative charge (anode), and a positively charged lead dioxide metal plate (cathode). The plates are suspended in the electrolyte to store electricity.

Saltwater

Saltwater battery systems replace lithium with sodium, the element found in table salt, resulting in a saltwater solution that can capture, store, and discharge energy. Saltwater batteries are recyclable and have a long lifecycle, but may not have the same energy storage capacity.

Environmental Impact of the Minerals in Solar Batteries

Lithium and lead can be problematic if released into the environment without proper care.

Lithium

During lithium mining, toxic chemicals may be released into nearby bodies of water, contaminating and causing harm to aquatic life and animals that drink from that source.

Lead

Whether released during mining or by disposing of a battery improperly, lead-acid particles can leak into the soil, air, and water. Over time, this can cause considerable pollution.

How to Know if Clean Energy is Right for Your Home

Learning more about solar science may give you a little more insight into solar energy being right for your life and your home. Solar power will be a cleaner and greener option for the energy you and your home uses. The mining and manufacturing that goes into solar panels and batteries should be reducing environmental concerns while solar technology strives to be a long-term environmental solution. 

If you want to learn more about installing solar panels and saving money by using solar power for your home energy, you can start by contacting Palmetto or by using our free solar design and savings estimate tool to see how solar panels would look on your roof and what you could save by going solar.

Frequently Asked Questions

What are common minerals in solar batteries?

Lithium is used in the majority of solar batteries. Lithium-ion batteries may also contain chromium, cobalt, graphite, manganese, and vanadium. There are solar batteries made with lead and saltwater, as well.

What are common minerals in solar panels?

Most solar panels contain aluminum, cadmium, copper, gallium, indium, lead, molybdenum, nickel, silicon, silver, selenium, tellurium, tin, and zinc.

Are solar panels and solar batteries safe to have at home?

Yes, solar panels and solar batteries are safe. The US surpassed five million solar power installations, with 97% of the installations being residential installations, in May 2024.

Sobre el AutorAndrew GiermakWriter and Editor

Andrew joined Palmetto in Charlotte in August 2024. He’s been a writer in journalism, then in business, going back to almost the 20th century. He’s lived in Indiana, Virginia, Pennsylvania, Virginia again, and now North Carolina for the last 12 years. He likes golf. Is he good at it? Not so much.