Batteries Slay the Duck Curve: A 37% Gas Reduction Thanks to Massive Storage

Introduction

The energy landscape is shifting, one quirky phenomenon called the duck curve is stirring up some challenges for our power grids, especially in sunny spots like California. This curve, named for its distinctive shape, highlights a mismatch between solar power generation and demand, is creating headaches for grid operators. As we push toward cleaner energy solutions, understanding this issue and how batteries are stepping up to address it is key. Let’s explore what the duck curve is, why it’s a problem, how it’s nudging energy costs upward, and the role batteries are playing in smoothing things out, all while tracking the impressive battery capacity installed in California since 2010.

The Duck Curve Increasing Energy Costs

The duck curve is a graphical representation of net electricity demand over a day, where solar power generation dips in the evening as the sun sets, causing a sharp rise in demand that resembles a duck’s belly and neck. In California, where solar dominates renewable energy, this curve emerges because midday solar output often exceeds demand, only for that surplus to vanish by late afternoon when people crank up air conditioners and appliances. This creates a steep ramping need, forcing grid operators to rely on backup sources.

The problem lies in the grid’s struggle to balance this variability. Operators must ramp up fossil fuel plants, like natural gas, quickly to meet evening peaks, which is inefficient and costly. The trending summary notes a 37% reduction in natural gas use in 2025 thanks to batteries, hinting at the previous reliance. This inefficiency drives up energy costs because gas plants, often idle during the day, burn fuel at premium rates during spikes, sometimes exceeding $1,000/MWh compared to $50/MWh for solar. Additionally, the need for rapid adjustments wears down equipment, adding maintenance expenses. The NPR article from October 6, 2025, points out rising electricity bills due to grid strain, with distribution costs climbing as old infrastructure struggles with these swings. So, the duck curve not only challenges reliability but also inflates costs for consumers and utilities alike.

How Are Batteries Mitigating the Duck Curve

Batteries are becoming the unsung heroes in tackling the duck curve, storing excess solar energy during the day and releasing it when demand spikes. In California, the trending data shows batteries supplied over 25% of peak demand in spring and summer 2025, a game-changer for evening ramps. They charge when solar production peaks, soaking up that midday surplus, and discharge in the late afternoon to early evening, flattening the curve’s steep rise. The Financial Times chart from Jigar Shah’s post, covering June 2025, illustrates this perfectly, with batteries kicking in around 6 PM as solar fades.

This mitigation reduces reliance on gas plants, cutting fuel costs and emissions. The 37% drop in natural gas generation since 2023, per the trend summary, underscores this shift. Batteries also enhance grid stability, avoiding the wear-and-tear costs of frequent plant startups. The Economist article suggests pairing this with demand response, but batteries alone are proving effective, with California avoiding Flex Alerts since 2022, as noted in the LA Times. Globally, with capacity up 67% to 617 GWh this year, this approach is scaling, driven by cost drops over 90% since 2010. It’s a smart, sustainable move to keep our grids humming while leaning on renewables.

Battery Capacity Installed in California

Since 2010, California has built an impressive battery infrastructure to support its clean energy goals. Based on the LA Times figure of 15,700 MW by October 2025, plus an estimated 1,500 MW from 2010 to 2019, the total power capacity reaches 17,200 MW, or 17.2 GW. To convert this to energy capacity in watt-hours, we need the discharge duration. Most grid-scale lithium-ion batteries offer 4 to 6 hours, with a 4.5-hour average being reasonable based on CAISO data and project specs like Moss Landing. Thus, energy capacity is calculated as 17.2 GW x 4.5 hours = 77.4 GWh.

Breaking it down, 1.5 GW from 2010-2019 yields 6.75 GWh, while 15.7 GW from 2020-2025 contributes 70.65 GWh. This 77.4 GWh reflects a robust build-out, aligning with California’s 55% share of US storage capacity per Reuters. Variations in duration (e.g., 4 vs. 6 hours) or ongoing projects might adjust this slightly, but it’s a solid estimate for 2025.

Table: Battery Capacity in California Since 2010

Period	Power Capacity (GW)	Duration (Hours)	Energy Capacity (GWh)
2010-2019	1.5	4.5	6.75
2020-2025	15.7	4.5	70.65
Total	17.2	4.5	77.4

As you can see in this table, in just the first 5 years of the 2020's, California has installed more than 10 times the battery energy capacity than they had in all of the previous decade.

Fossil Fuel Reduction

In California, methane use for electricity generation has dropped significantly due to renewable energy and batteries. There's been a 37% reduction in natural gas electricity generation during peak periods in 2025 compared to 2023, driven primarily by grid-scale batteries. These batteries store excess solar energy during the day and release it at night, mitigating the duck curve. This reduces reliance on gas-fired peaker plants, which burn methane, the primary component of natural gas (about 80%), ethane, propane, and butane. Solar power, dominating renewables, provides the surplus energy batteries utilize, cutting the need for fossil fuels. The LA Times notes a 3,000% battery capacity growth since 2020. This is a significant cut in fossil fuel use in the electricity sector. This shift lowers costs and emissions.

Conclusion

The duck curve is a fascinating challenge that highlights the growing pains of our shift to renewable energy, pushing up costs with its demand spikes and reliance on gas. Batteries are stepping up, storing solar power and easing evening peaks, as seen in California’s 37% gas reduction. With 77.4 GWh of capacity installed since 2010, we’re on a promising path. With continued innovation, we can keep costs down while powering our future sustainably.