How Building More Wind Turbines Could Actually Increase Emissions

How Building More Wind Turbines Could Actually Increase Emissions

Introduction

The expansion of wind power is widely regarded as an important strategy for reducing greenhouse gas emissions and mitigating climate change. However, some recent research suggests that building large numbers of new wind turbines could actually lead to increased emissions in some cases.

In this article, I will examine the mechanisms by which additional wind capacity might increase emissions, look at real-world examples where this has occurred, and discuss potential solutions to prevent unintended emissions consequences. Understanding these complex interactions is key for ensuring the continued growth of wind power achieves the intended climate benefits.

How More Wind Turbines Could Increase Emissions

There are a few different ways that building large amounts of new wind generation could theoretically increase emissions:

Displacing Low-Carbon Nuclear

In regions that get a large share of their electricity from zero-carbon sources like nuclear power, adding significant wind capacity could push out those existing low-carbon sources. For example, a major expansion of wind in a nuclear-heavy grid could reduce the financial viability of the nuclear plants, leading some to retire earlier than planned. If the nuclear plants are replaced by fossil fuels, this could increase overall emissions.

Transmission Constraints

In some cases, major wind expansion could overload transmission networks that lack sufficient capacity. This could force grid operators to curtail the output of wind turbines to avoid overloading lines. Curtailing wind means its generation must be replaced by ramping up fossil fuel plants, leading to higher emissions. Building out transmission could alleviate constraints, but requires long lead times.

Cycling of Fossil Fuel Plants

The intermittent nature of wind power output requires backup generation from flexible sources like natural gas plants that can quickly ramp up and down. Cycling these fossil plants to accommodate wind variability can decrease their efficiency and increase wear-and-tear, leading to higher emissions rates when they do run.

Market Effects

A surge in new wind capacity could cut wholesale electricity prices due to low operational costs. This reduces profitability of zero-carbon nuclear plants and makes them more likely to retire. It also reduces incentives for building new low-carbon generation. The ultimate outcome could be increased reliance on fossil fuels.

Real-World Examples Where Wind Buildout Increased Emissions

While the mechanisms described above are hypothetical in some cases, there is evidence from real-world examples that rapid wind expansion can increase emissions under certain conditions:

Texas

Texas rapidly added wind capacity in the early 2000s due to renewable incentives. While wind generation increased, so too did coal generation as natural gas plants were cycled more frequently. The end result was higher CO2 emissions from the Texas grid during some periods.

Ireland

Ireland has expanded wind generation substantially, which reduced wholesale electricity prices. This made operation of zero-carbon natural gas unprofitable, leading to increased reliance on high-carbon peat and coal plants. More wind ultimately increased the carbon intensity of Ireland’s electricity.

Germany

Germany has aggressively grown wind and solar capacity. But it has also retired nuclear plants faster than planned after Fukushima. Fossil fuels have filled the gap, and Germany’s carbon emissions have stagnated. More renewables have so far failed to cut emissions due to nuclear phase out.

Solutions to Prevent Unintended Consequences

While adding wind generation can clearly increase emissions in some situations if not done properly, there are solutions that can help expand wind capacity while also reducing greenhouse gases:

Coordinate Wind Buildout with Grid Upgrades

Building transmission and distribution should be coordinated with adding new wind farms. This prevents overloading networks and need for curtailment.

Maintain Existing Low-Carbon Sources

Phasing out nuclear, hydro, or other low-carbon sources during wind expansion will blunt emissions reductions. Policy should aim to maintain these while growing renewables.

Improve Cycling Operation of Fossil Plants

Upgrades like faster start-up and ramping for natural gas plants can reduce inefficiencies during cycling to accommodate wind variability.

Reform Electricity Markets

Market rules that improve incentives for low-carbon sources and flexibility can prevent unintended consequences as more wind comes online.

Conclusion

Rapid expansion of wind generation can theoretically increase emissions by displacing low-carbon sources, overloading grids, forcing fossil plant cycling, and distorting electricity markets. Real-world examples show this can occur under some policies and power system configurations. But solutions like coordinated planning, grid upgrades, maintaining nuclear, flexible gas plants, and market reforms can realize the full emissions benefit from growing wind capacity. Policymakers must consider these complex interactions when pursuing deep decarbonization pathways.