What the EU ETS is and how it operates

The EU Emissions Trading Scheme (EU ETS) is a cap-and-trade system that limits carbon dioxide and other greenhouse gas emissions from large industrial facilities and power plants across Europe. Instead of setting rules about how each facility must cut emissions, the EU sets a total emissions cap for the whole system and lets individual operators buy and sell allowances—each allowance permits one tonne of CO₂ equivalent to be released.

The scheme works like this: the EU gradually lowers the overall cap each year, making allowances scarcer and more expensive over time. Facilities that emit less than their allowance can sell their unused permits to others. Facilities that emit more must buy additional allowances or face steep fines. This creates a financial incentive to reduce emissions, because cutting pollution becomes cheaper than buying allowances at market prices.

The EU ETS launched in 2005 and is the world's largest carbon market by trading volume. It covers roughly 40% of the EU's greenhouse gas emissions, focusing on the sectors that produce the most: power generation, oil refining, steel, cement, chemicals, and paper manufacturing. Aviation was added in 2012, though with some exemptions for flights to non-EU countries.

Key Takeaways

  • The EU ETS caps total emissions from covered sectors and lets operators trade allowances, creating a price signal that rewards cutting pollution.
  • The cap falls each year by a fixed percentage, so allowances become scarcer and more expensive, pushing industries toward lower-emission processes.
  • Facilities that reduce emissions below their allocation can sell allowances; those that exceed it must buy more or pay fines of €100 per tonne of excess emissions.
  • The scheme covers power plants, refineries, steel mills, cement works, chemical plants, and airlines, but not small businesses, transport, or agriculture.
  • Revenue from allowance auctions funds climate and energy projects in EU member states, with some money reserved for supporting lower-income countries.

How allowances are allocated and priced

In the first two phases of the EU ETS (2005–2007 and 2008–2012), most allowances were given free to existing facilities based on their historical emissions—a method called grandfathering. This approach was meant to ease the transition but also meant polluters got a windfall: they could sell allowances they received for nothing and pocket the revenue.

Since 2013, the system has shifted toward auctioning. The EU now sells most allowances to the highest bidder through regular online auctions, and the price is set by supply and demand. Facilities no longer receive free permits just for existing; instead, some sectors deemed at risk of relocating to countries with weaker climate rules still receive free allowances to protect their competitiveness. Steel, cement, chemicals, and refining get partial free allocation; power plants do not.

The allowance price has risen significantly over time. In 2020, allowances traded around €25 per tonne; by 2023, prices had climbed above €80 per tonne as the cap tightened and demand for low-carbon alternatives grew. This price increase is intentional—it makes polluting more expensive and clean technology more attractive by comparison.

Who is covered and who is exempt

The EU ETS covers facilities that emit more than a certain threshold: power plants with a thermal input above 20 megawatts, refineries, steel mills, cement works, lime kilns, glass furnaces, ceramic kilns, and chemical plants. Airlines operating flights within the EU airspace are also covered, though with a partial exemption for routes to non-EU countries.

Small and medium-sized businesses are not covered, even if they emit greenhouse gases. A bakery, a small manufacturing plant, or a local transport company does not participate in the ETS. Emissions from agriculture, road transport, and heating in buildings are not included in the scheme—those sectors are addressed through other EU climate policies.

Some facilities can opt out if they meet strict energy-efficiency standards through an alternative scheme called the Energy Efficiency Directive. This allows them to reduce emissions through efficiency improvements instead of buying allowances, but they must meet demanding targets and report regularly.

The Carbon Border Adjustment Mechanism and future expansion

Starting in 2026, the EU is introducing the Carbon Border Adjustment Mechanism (CBAM), which will require importers of certain goods to pay a carbon price if those goods were produced in countries with weaker climate rules than the EU. CBAM covers cement, steel, iron, aluminium, fertilizers, and electricity initially, with possible expansion to other sectors.

CBAM is designed to prevent carbon leakage—the risk that EU industries relocate to countries outside the scheme to avoid the cost of allowances. By making imports more expensive if they come from high-carbon sources, CBAM aims to level the playing field between EU producers (who must buy allowances) and foreign competitors (who may not face similar costs).

The EU has also proposed expanding the ETS to cover maritime shipping and to create a separate scheme for buildings and road transport by 2026. These expansions would bring more emissions under the cap-and-trade framework, though the details and timeline remain subject to negotiation among member states.

How compliance and penalties work

Each year, facility operators must report their actual emissions to their national regulator by March 31 of the following year. The report must be verified by an independent third party and include data on fuel consumption, production, and any emissions reductions achieved. Facilities that fail to report or submit false data face administrative penalties and potential criminal prosecution.

By April 30, each facility must surrender allowances equal to its verified emissions from the previous year. If a facility emitted 100,000 tonnes of CO₂ in 2023, it must hand over 100,000 allowances by the important date. Allowances can come from free allocation, purchases at auction, or trades with other operators.

If a facility does not surrender enough allowances, it must pay an excess emissions penalty of €100 per tonne (adjusted annually for inflation). The facility must also surrender the missing allowances the following year. Repeated non-compliance can result in exclusion from the scheme and substantial fines under national law.

Revenue use and financial support for member states

Revenue from allowance auctions belongs to EU member states, not to the European Commission. In 2022, the EU ETS generated roughly €38 billion in auction revenue across all member states. Each country decides how to spend its share, though the EU requires that at least 50% of revenue be used for climate and energy projects.

Common uses include funding renewable energy infrastructure, energy efficiency retrofits in buildings, support for workers and regions dependent on coal, and climate research. Some member states use ETS revenue to reduce other taxes or to fund public transport. Wealthier countries often invest more in clean technology; lower-income member states receive additional support through the EU budget to help them transition away from fossil fuels.

The EU also sets aside a portion of allowances to support developing countries through the Climate Investment Funds, though this mechanism has been reformed several times and remains politically contested.

How the EU ETS compares to other carbon pricing systems

The EU ETS is a cap-and-trade system, meaning the government sets a hard limit on total emissions and lets the market determine the price. Other regions use carbon taxes instead, which set a price per tonne and let the market determine how much emissions fall. Canada, Sweden, and Switzerland use carbon taxes; the EU chose cap-and-trade because it guarantees a specific emissions reduction.

China operates a separate emissions trading scheme that covers power generation and some heavy industry, but it is smaller and less transparent than the EU ETS. California's cap-and-trade system covers power, large industrial facilities, and fuel distributors, and it links with Quebec's scheme. New Zealand and South Korea also run ETS programs, but the EU scheme remains the largest and most established.

The advantage of cap-and-trade is certainty about the emissions outcome; the disadvantage is price volatility, which can make long-term investment planning difficult for covered industries. Carbon taxes provide price certainty but leave the emissions outcome uncertain. The EU chose cap-and-trade partly because it wanted to may provide that emissions fell by a specific amount each year.

Frequently Asked Questions

Does the EU ETS cover my business?

The scheme covers large power plants, refineries, steel mills, cement works, chemical plants, and airlines. If your facility has a thermal input above 20 megawatts or is one of the listed industrial sectors, you are covered. Small businesses, offices, shops, and local transport companies are not included. Your national environmental regulator can confirm whether your facility meets the threshold.

What happens if allowance prices get too high?

High allowance prices create pressure on covered industries to cut emissions or pass costs to consumers, which is the intended effect. The EU has no price cap or floor; prices are set by supply and demand at auction. During periods of high prices, some industries lobby for free allowances or exemptions, but the EU has resisted these requests to maintain the scheme's environmental integrity.

Can a facility buy allowances from previous years?

Yes. Allowances can be banked and used in future years, which means a facility can buy extra allowances in a low-price year and use them later. This flexibility helps operators manage costs, but it also means the cap can be delayed if too many allowances are banked. The EU has tightened banking rules over time to prevent this.

How does the EU ETS affect consumer prices?

Allowance costs are passed through to consumers in the form of higher electricity and fuel prices, though the effect varies by country and sector. A facility that buys allowances at €80 per tonne will raise its prices to recover that cost. Studies suggest the EU ETS has raised electricity prices by 5–15% depending on the region and year, though other factors like fuel costs and demand also play a large role.

What is the difference between Phase 4 and earlier phases?

Phase 4 (2021–2030) is the current period and features a faster annual cap reduction (4.2% per year instead of 1.74%), more auctioning instead of free allowances, and the introduction of CBAM. Earlier phases had higher free allocation, slower cap reductions, and lower allowance prices. Phase 4 is designed to accelerate emissions cuts in line with the EU's 2030 climate target of 55% emissions reduction.