How Building More Wind Turbines Could Actually Increase Greenhouse Gas Emissions

Fossil fuels are a major contributor to climate change. As the world seeks cleaner energy sources, wind power has emerged as a popular renewable alternative. But counterintuitively, building more wind turbines could actually increase greenhouse gas emissions in some cases. Here's an in-depth look at how this could happen:

The Intermittency Problem

Wind power suffers from intermittency - the wind doesn't blow all the time. When it's not windy, traditional power plants, usually fueled by coal or natural gas, need to step in to meet electricity demand. This means that adding wind power doesn't always displace fossil fuels - it can simply end up being an additional source.

For example, a 2021 study by researchers at Stanford University found that between 2010 and 2018, building thousands of new wind turbines in the Midwest did not actually cut carbon emissions. That's because the new wind generation was intermittent, so fossil fuel plants still had to operate to fill in the gaps. The end result was more total electricity generation, but no net reduction in emissions.

“Our findings suggest that simply building more wind farms will not be enough to reduce carbon emissions,” said lead author Sally Benson, professor of energy resources engineering at Stanford.

The Network Effect

There is also a “network effect” that can lead to higher emissions with more wind power. Electricity grids need to constantly match supply with demand. More variable wind power entering the grid leads grid operators to keep extra fossil fuel generation on standby for when wind suddenly drops off.

These natural gas plants then operate at less efficient levels, starting up and ramping down more often to accommodate wind's intermittency. That leads to more emissions per unit of electricity generated. A 2021 study from researchers at Carnegie Mellon University analyzed real-world emissions data and found adding wind power to the grid could increase carbon dioxide emissions from fossil fuel plants by up to 20% per megawatt-hour.

Difficulty Decommissioning Old Plants

Ideally, building new wind turbines allows old fossil fuel plants to fully retire. But grid reliability requirements can make it difficult to take coal and natural gas plants offline. These facilities provide essential grid services like inertia and voltage support that renewables may lack.

So some fossil fuel capacity has to remain online even as new wind gets added. For example, despite rapid growth in wind power in Germany and Texas, only minimal coal capacity in those markets has been decommissioned. The old plants stick around as backup, enabling continued emissions.

The Solution

Clearly, intermittency and grid integration issues present challenges for maximizing wind power's climate benefits. But solutions exist. The key is building wind in tandem with large-scale energy storage.

Batteries and pumped hydro storage can soak up excess wind energy and discharge it when needed. With enough storage to overcome intermittency, wind and solar can fully displace fossil fuel plants.

Grid coordination over larger areas also helps smooth out wind's variability. And investing in new high-voltage transmission lines allows distant renewable energy to reach load centers.

With smart policies and grid upgrades, wind power can still be a crucial zero-carbon resource. But the integration challenges are real. Simply building more turbines and expecting emissions to drop may yield disappointing results in some energy systems. Careful planning and coordination with storage, transmission, and existing plants is essential.