What is the carbon footprint of offshore wind?

Manufacturing and constructing offshore wind turbines does produce some emissions. But these are very small in comparison to emissions from fossil fuels – and vastly outweighed by the emissions saved by using offshore wind instead of fossil fuels.

Question:

Is more carbon dioxide emitted during the process of manufacturing a wind turbine than saved while it generates electricity?

Fact:

The carbon saved throughout a wind turbine’s lifespan is up to 50 times greater than the emissions from its manufacture, construction, operation and decommissioning.

The real emissions from wind power

The manufacture, installation, operation and eventual decommissioning of offshore wind turbines emits carbon dioxide.

To put it simply, the production of steel and other components, as well as vessel transport and heavy transportation, involve burning fossil fuels. We’re working on carbon-neutral alternatives for the future, but today, these processes are unavoidable when building offshore wind.

An offshore wind turbine by an onshore factory emitting carbon represent the limited carbon footprint of offshore wind.

99% lower emissions than fossil fuels

But most of these emissions only need to happen once for each wind turbine, which will be in service for at least 25 years. In this time, they will be producing electricity without emitting any more carbon dioxide, except for those from the vessels used for service and maintenance. These account for about 10% of total emissions from offshore wind.

When you divide the total emissions associated with a wind turbine by the amount of electricity it will produce in its lifetime, it works out at about 6 g of carbon dioxide for every kilowatt-hour (kWh) of electricity.¹By comparison, power generation based on fossil fuels involves burning more coal, oil or gas for every kWh of electricity, on top of the one-off carbon emissions from construction and decommissioning. For coal, this adds up to approximately 900 g per kWh.

In other words, switching from coal-fired generation to wind power can reduce the carbon emitted from energy production by more than 99%.

Comparison of the lifetime emissions of an offshore wind turbine (6 g/kWh) and a coal-based power plant (600 g/kWh).

Average carbon emissions per kilowatt-hour based on global coal-based power production.²

Ørsted on track for 98% emissions reductions by 2025

Even though our activities as a renewable energy company do involve creating some carbon emissions, we’re on track to reduce the emissions intensity of our energy generation by 98% from 2006 levels. This puts us significantly ahead of the science-based targets for the energy sector for limiting global warming to 1.5 °C.

Beyond that, we're the first energy company in the world with a net-zero target validated by the Science Based Targets initiative. We aim to reach net-zero emissions across our entire value chain by 2040.

Graph showing Ørsted's falling carbon intensity compared to the Science-Based Targets initiative pathway, from 2010-2050.

How do we achieve net-zero emissions?

In energy generation and operations, we will have almost entirely replaced our use of fossil fuels with renewable energy by 2025. For the rest of our footprint, we’re phasing out wholesale buying and selling of natural gas, and working with suppliers to decarbonize our value chain.

Emission-free wind power on the horizon?

When it comes to the emissions that are the most difficult to eliminate, one option is carbon offsetting. This means preventing other carbon emissions to compensate for our own.

But what if we could avoid emitting that last 6 g of carbon dioxide from each kWh of offshore wind power in the first place? There are solutions on the horizon that could make this possible.

We’re already working with strategic suppliers to ensure that all electrical processes in the manufacture of wind turbines use renewable electricity by 2025.

In the medium term, we will also provide guidelines to make sure that sustainable biofuels are used in activities like shipping where possible. We’re also exploring possibilities including using renewable hydrogen, synthetic fuels based on carbon extracted straight from the atmosphere, or even battery-driven vessels that would by charged using renewable electricity.