Meet the power plant of the future: Solar + battery hybrids poised for explosive growth
By pairing solar power and battery storage, hybrids can keep providing electricity after dark. Petmal via Getty Images
America’s electric power system is undergoing radical change as it transitions from fossil fuels to renewable energy. While the first decade of the 2000s saw huge growth in natural gas generation, and the 2010s were the decade of wind and solar, early signs suggest the innovation of the 2020s may be a boom in “hybrid” power plants.
A typical hybrid power plant combines electricity generation with battery storage at the same location. That often means a solar or wind farm paired with large-scale batteries. Working together, solar panels and battery storage can generate renewable power when solar energy is at its peak during the day and then release it as needed after the sun goes down.
A look at the power and storage projects in the development pipeline offers a glimpse of hybrid power’s future.
Our team at Lawrence Berkeley National Laboratory found that a staggering 1,400 gigawatts of proposed generation and storage projects have applied to connect to the grid — more than all existing U.S. power plants combined. The largest group is now solar projects, and over a third of those projects involve hybrid solar plus battery storage.
While these power plants of the future offer many benefits, they also raise questions about how the electric grid should best be operated.
Why hybrids are hot
As wind and solar grow, they are starting to have big impacts on the grid.
Solar power already exceeds 25% of annual power generation in California and is spreading rapidly in other states such as Texas, Florida and Georgia. The “wind belt” states, from the Dakotas to Texas, have seen massive deployment of wind turbines, with Iowa now getting a majority of its power from the wind.
This high percentage of renewable power raises a question: How do we integrate renewable sources that produce large but varying amounts of power throughout the day?
Joshua Rhodes/University of Texas at Austin.
That’s where storage comes in. Lithium-ion battery prices have rapidly fallen as production has scaled up for the electric vehicle market in recent years. While there are concerns about future supply chain challenges, battery design is also likely to evolve.
The combination of solar and batteries allows hybrid plant operators to provide power through the most valuable hours when demand is strongest, such as summer afternoons and evenings when air conditioners are running on high. Batteries also help smooth out production from wind and solar power, store excess power that would otherwise be curtailed, and reduce congestion on the grid.
Hybrids dominate the project pipeline
At the end of 2020, there were 73 solar and 16 wind hybrid projects operating in the U.S., amounting to 2.5 gigawatts of generation and 0.45 gigawatts of storage.
Today, solar and hybrids dominate the development pipeline. By the end of 2021, more than 675 gigawatts of proposed solar plants had applied for grid connection approval, with over a third of them paired with storage. Another 247 gigawatts of wind farms were in line, with 19 gigawatts, or about 8% of those, as hybrids.
The amount of proposed solar, storage and wind power waiting to hook up to the grid has grown dramatically in recent years, while coal, gas and nuclear have faded. Lawrence Berkeley National Laboratory
Of course, applying for a connection is only one step in developing a power plant. A developer also needs land and community agreements, a sales contract, financing and permits. Only about one in four new plants proposed between 2010 and 2016 made it to commercial operation. But the depth of interest in hybrid plants portends strong growth.
In markets like California, batteries are essentially obligatory for new solar developers. Since solar often accounts for the majority of power in the daytime market, building more adds little value. Currently 95% of all proposed large-scale solar capacity in the California queue comes with batteries.
5 lessons on hybrids and questions for the future
The opportunity for growth in renewable hybrids is clearly large, but it raises some questions that our group at Berkeley Lab has been investigating.
Here are some of our top findings:
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The investment pays off in many regions. We found that while adding batteries to a solar power plant increases the price, it also increases the value of the power. Putting generation and storage in the same location can capture benefits from tax credits, construction cost savings and operational flexibility. Looking at the revenue potential over recent years, and with the help of federal tax credits, the added value appears to justify the higher price.
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Co-location also means tradeoffs. Wind and solar perform best where the wind and solar resources are strongest, but batteries provide the most value where they can deliver the greatest grid benefits, like relieving congestion. That means there are trade-offs when determining the best location with the highest value. Federal tax credits that can be earned only when batteries are co-located with solar may be encouraging suboptimal decisions in some cases.
Hybrid power has become standard in Hawaii as solar power saturates the grid. Dennis Schroeder/NREL
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There is no one best combination. The value of a hybrid plant is determined in part by the configuration of the equipment. For example, the size of the battery relative to a solar generator can determine how late into the evening the plant can deliver power. But the value of nighttime power depends on local market conditions, which change throughout the year.
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Power market rules need to evolve. Hybrids can participate in the power market as a single unit or as separate entities, with the solar and storage bidding independently. Hybrids can also be either sellers or buyers of power, or both. That can get complicated. Market participation rules for hybrids are still evolving, leaving plant operators to experiment with how they sell their services.
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Small hybrids create new opportunities: Hybrid power plants can also be small, such as solar and batteries in a home or business. Such hybrids have become standard in Hawaii as solar power saturates the grid. In California, customers who are subject to power shutoffs to prevent wildfires are increasingly adding storage to their solar systems. These “behind-the-meter” hybrids raise questions about how they should be valued, and how they can contribute to grid operations.
Hybrids are just beginning, but a lot more are on the way. More research is needed on the technologies, market designs and regulations to ensure the grid and grid pricing evolve with them.
While questions remain, it’s clear that hybrids are redefining power plants. And they may remake the U.S. power system in the process.
Joachim Seel receives funding from the US Department of Energy.
Bentham Paulos receives funding for this work from the US Department of Energy.
Will Gorman receives funding for this work from the US Department of Energy.
This article is republished from The Conversation under a Creative Commons license.
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Meet the power plant of the future: Solar + battery hybrids poised for explosive growthtchara // Shutterstock
The European Union in 2020 sourced 21.3% of its energy from renewables, surpassing its 2009 goal. With most of the continent’s energy came from oil and petroleum products, its announcement was one of the first ambitious global promises to address climate change. Within the broad range of renewable energy sources Europe relied upon, one source accounted for nearly half of the continent’s renewable supply: biomass.
Broadly, biomass is any organic material used as fuel and can include manure, agricultural or industrial waste, garbage, and most prominently, wood. Burning wood for fuel is nothing new: As countries transition away from coal and other fossil fuels, the popularity of biomass increases, leading to a spike in demand for wood pellets.
Stacker cited data from the International Trade Center, Eurostat, and the Southern Environmental Law Center to examine how the growing wood pellet industry in the U.S. is fueling European energy, despite its controversial environmental reputation.
The 1997 Kyoto Protocol first considered wood pellets a carbon-neutral energy source. The world was beginning to think more seriously about climate change at the time, and pellets became an easy substitute to transition away from coal-powered facilities. Woody biomass companies replant trees while harvesting timber, allowing young forests to absorb carbon while justifying biomass as a renewable energy source. But biomass’s carbon neutrality is not immediate: It takes years for new saplings to meet the carbon-absorption capacity of older trees being harvested. Meanwhile, wood pellets are burned and emit the CO2 once stored by the wood. The resulting carbon debt can take decades for newly planted trees to offset.
Scientists also note that considering wood pellets carbon-neutral overlooks emissions from the supply chain. An analysis from the Environmental Integrity Project published in 2018 found that 21 wood pellet facilities exporting to Europe emitted 16,000 tons of air pollutants annually. Transportation in cross-Atlantic vessels is another phase that often goes unaccounted for in woody biomass’s carbon calculations.
Scientists have begun to question the sustainability of woody biomass, and whether the displacement of one fossil fuel is now causing the disruption of forest ecosystems—all while still emitting greenhouse gases. Read on to learn about the complexities of renewable energy.
You may also like: The 90 companies responsible for two-thirds of historical greenhouse gas emissions
tchara // ShutterstockThe European Union in 2020 sourced 21.3% of its energy from renewables, surpassing its 2009 goal. With most of the continent’s energy came from oil and petroleum products, its announcement was one of the first ambitious global promises to address climate change. Within the broad range of renewable energy sources Europe relied upon, one source accounted for nearly half of the continent’s renewable supply: biomass.
Broadly, biomass is any organic material used as fuel and can include manure, agricultural or industrial waste, garbage, and most prominently, wood. Burning wood for fuel is nothing new: As countries transition away from coal and other fossil fuels, the popularity of biomass increases, leading to a spike in demand for wood pellets.
Stacker cited data from the International Trade Center, Eurostat, and the Southern Environmental Law Center to examine how the growing wood pellet industry in the U.S. is fueling European energy, despite its controversial environmental reputation.
The 1997 Kyoto Protocol first considered wood pellets a carbon-neutral energy source. The world was beginning to think more seriously about climate change at the time, and pellets became an easy substitute to transition away from coal-powered facilities. Woody biomass companies replant trees while harvesting timber, allowing young forests to absorb carbon while justifying biomass as a renewable energy source. But biomass’s carbon neutrality is not immediate: It takes years for new saplings to meet the carbon-absorption capacity of older trees being harvested. Meanwhile, wood pellets are burned and emit the CO2 once stored by the wood. The resulting carbon debt can take decades for newly planted trees to offset.
Scientists also note that considering wood pellets carbon-neutral overlooks emissions from the supply chain. An analysis from the Environmental Integrity Project published in 2018 found that 21 wood pellet facilities exporting to Europe emitted 16,000 tons of air pollutants annually. Transportation in cross-Atlantic vessels is another phase that often goes unaccounted for in woody biomass’s carbon calculations.
Scientists have begun to question the sustainability of woody biomass, and whether the displacement of one fossil fuel is now causing the disruption of forest ecosystems—all while still emitting greenhouse gases. Read on to learn about the complexities of renewable energy.
You may also like: The 90 companies responsible for two-thirds of historical greenhouse gas emissions
