Energy storage is fast becoming one of the most talked-about sustainable energy fields.
Governments and citizens are increasingly aware of the interconnected nature of power generation and consumption within energy systems. People want to know how clean energy and renewable energy sources can become reliable contributors to the power grid.
But electrical energy cannot be stored as it is — it needs to be housed somewhere in another form. Let’s examine how energy storage systems may allow us to make the most of global energy resources and help us meet our energy needs.
What Is the Definition of Energy Storage?
Energy storage refers to various methods of capturing and storing energy produced for later use. Captured energy comes in multiple forms, from chemical to gas or heat.
How Do We Use Energy Storage Systems?
Typically, power grid operators control our energy needs by matching demand with supply. Fossil fuel-based power plants fire up to create electricity or pump natural gas to homes and industry. The growth of renewable energy sources has brought diversification in energy creation.
For example, in December 2019, a storm over the U.K. saw wind turbines creating more energy than people could consume at times. Households didn’t use all of the clean energy produced. Energy storage systems are designed to draw this excess from the electricity grid and push it back into the grid later, usually when demand is high.
Energy storage systems save excess energy — it’s like storing money for a rainy day. This storage can be controlled and released when required, bringing flexibility to utility-scale and smaller power systems.
Why Is Energy Storage Important for Power Grids?
Humanity’s appetite for energy is expected to increase unabated, rising almost 50% between 2018 and 2050.
Traditionally, power plants would burn fossil fuel-based sources like coal, natural gas, and oil to produce electricity. Supply met demand, and companies could handle energy levels to avoid wastage.
Renewables are not reliable in the same way as fossil fuels; the sun may not shine, and the wind may not blow. Renewables can also produce large excesses of energy, as we saw with the U.K. storm. These new energy sources have variable power qualities.
Excess energy, especially from renewable sources, ensures we utilize our energy resources fully. “Sustainability” is now the watchword for many countries trying to hit net-zero emissions by 2050 in the battle against climate change.
Releasing stored energy back into both utility-scale power grids and smaller microgrids makes balancing loads easier, too. Operators can smooth demand peaks and lows into more dependable, flatter lines.
What Types of Energy Storage Systems Exist?
Energy storage systems, or ESS, come in many forms, some of which may already be familiar. Here are the principle systems:
- Battery systems (ABES): Batteries are among the most recognizable energy storage systems, from regular rechargeables to grid-scale. Flow batteries include lithium-ion and lead-acid and many other types of battery technology.
- Hydropower: Reservoir water held back by a dam is a form of potential or stored energy. We create electricity by releasing the water to turn a turbine.
- Compressed Air Energy Storage (CAES): Excess energy in grids can be used to compress air to store underground. The pressurized air is released when required, turning turbines to create electricity.
- Thermal energy storage (TES): A liquid or solid is heated (or cooled), producing thermal energy stored for later use. For example, utility-scale solar farms may superheat salts when the sun shines. When the sun sets, the hot salts create steam to drive an electricity-producing turbine, meaning some solar farms can produce energy 24 hours a day.
- Hydrogen Energy Storage (HES): Electrolysis separates hydrogen from water or other solutions. The hydrogen is stored, which is especially helpful when renewables create excess energy. Hydrogen is versatile and may be used as a replacement for natural gas, or compressed and transported.
All these ESS configurations involve capturing, storing, and then releasing energy.
Which Is the Best Energy Storage System?
The best energy storage system depends on what energy storage solution you seek.
Battery systems are versatile from utility-scale to hand-held and portable sizes. Grid storage is possible, as well as charging batteries from solar, wind, or electrical sockets. Batteries do run down quickly, having what is known as weak duration storage properties.
Hydropower reservoirs are immense energy storage systems restricted by geography. They are excellent energy storage systems where rainfall or river water is abundant and large amounts of energy are required. Micro-hydro systems are useful at remote buildings close to fast-flowing streams, too.
Thermal energy storage is an excellent option for heating water and complementing power drawn from solar panels. Any system that creates heat may also use thermal energy storage for other uses, such as creating electricity at a solar farm.
Compressed air, hydrogen, and hydropower are long-duration energy storage systems. These large-scale technologies can dispense a lot of energy and keep it in storage for long periods. Hydrogen is portable, too, increasing its appeal.
How Much Power Comes From Energy Storage?
Energy storage is a reasonably new energy source around the globe, except for hydrogen.
In 2019, hydropower contributed 6.4% of the world’s entire energy mix, not just electricity. This makes it a significant part of the global energy storage system.
Hydrogen accounted for just 0.2% of worldwide electricity production in 2020. However, it has been touted as one of the future’s most important clean energies thanks to its versatility.
Hydrogen can power cars, heat homes, be transported to the point of use, and create electricity. We can even make hydrogen using renewable energy, giving it a low carbon footprint. The International Energy Agency believes hydrogen’s current high production cost could quickly drop with increased adoption rates.
Compressed air, thermal energy storage, and grid-scale batteries are currently niche players. There are just two CAES power plants worldwide, one in Germany and another in the U.S. state of Alabama.
Are There Lots of Battery Storage Systems?
Globally, around 17 gigawatts (GW) of battery storage centers are currently in use. China and the U.S. lead the way in adding extra battery storage capacity at a utility-scale level. Falling battery production costs — household lithium-ion battery costs have dropped more than 60% in Germany since 2014 — could increase battery storage.
Batteries form a small part of the energy mix — the world’s annual electricity consumption was more than 160,000 terawatt-hours (TWh) in 2019. This may improve as governments invest in more large-scale battery storage sites.
Another battery benefit is seen with the boom in electric vehicles (EVs), with more than 10 million already on the roads. An electric vehicle’s battery can push energy back into power grids using vehicle-to-grid (V2G) technology. The idea sees owners charging their automobiles when there are energy excesses then sending it into the system when there are energy shortfalls. Smart grids and meters may even see EV owners paid for the service.
Many businesses and homeowners installing small wind turbines or solar panels may also add a battery to capture any excess renewable energy they produce. Energy from sunny days can be utilized at night, and a windy evening recharges the battery overnight. Batteries add cost to these installations but help people make the most of their renewable energy resources.
All of these extra electricity storage options will help improve power grids’ ability to respond to changes in demand.
Does the United States Have Energy Storage Systems?
The United States’ primary energy storage system is hydropower, accounting for 6.3% of the country’s total electricity generation in 2021. That’s just under a third of the U.S. renewable energy sector.
Around a fifth of U.S. electricity generation comes from renewables — led by wind and hydro — but their supply is weather dependent. That’s why when the sun shines, or the wind blows, the grid needs energy storage systems to capture any excess energy.
Large-scale battery storage is very much in its infancy in the United States. Batteries will contribute an estimated 10,000 megawatts (MW) of electricity to the grid between 2021 and 2023, ten times greater than in 2019. It’s a mere drop in the ocean, though; the country generated more than 4 billion MW of electricity in 2021.
Texas and California, both at the forefront of renewable energy generation in the country, currently lead utility-scale battery storage. Long-term prospects look promising for batteries, with the capital cost for large-scale battery storage falling consistently of late. In 2019, prices reached a fifth of 2015’s dollar per kilowatt-hour cost, making it a more attractive investment.
Why Do We Need Energy Storage Systems?
The U.S. Department of Energy (DOE) has undertaken exhaustive research into the role of energy storage and the future of national power grids.
Called the Energy Storage Program, the DOE has also studied materials used in energy storage technologies to improve efficiency.
Recommendations for power grids include improving electricity delivery, reliability, and stability to customers with upgrades across distribution systems. Grid operators can already control electric power with precision, even over long distances, thanks to switches, inverters, and controllers.
However, the DOE believes costs must reduce soon to push energy storage projects forward. Energy storage solutions must come from innovation, too.
Is There a Future for Battery Storage Systems?
It’s not enough to boost capacity; the power quality also needs to raise the bar. The DOE states that technological research needs to focus on:
- Improving electrolytes in flow batteries to store more energy and redistribute it more efficiently.
- Developing sodium batteries that work at low temperatures for large-scale battery storage sites.
- More efficient electrochemical properties in a battery’s electrodes so electrolytes flow better. Efficiencies may help batteries store more power and distribute it over longer timescales.
A more efficient distribution system coupled with higher quality batteries, possibly with high power materials, could revolutionize battery storage’s potential.
A downside for storage systems is the raw materials and pollution created in their production. Reservoir dams require enormous amounts of cement and filling the basin devastates local wildlife. Batteries require minerals that pollute the environment during the mining process.
However, studies suggest battery production improvements and recycling mean electric vehicles produce three times fewer carbon dioxide emissions than a petrol or diesel automobile.
What Is an Energy Storage Molecule?
Energy storage molecules come in many forms. Batteries store energy as chemical energy in their electrodes. Humans use glucose as an energy storage molecule. The glucose transports chemical energy between our cells.Energy storage molecules come in many forms. Batteries store energy as chemical energy in their electrodes. Humans use the energy stored in glucose as an energy source. The glucose transports chemical energy between our cells. Plants convert sunlight into stored chemical energy, too, through photosynthesis.
Where Do Energy Storage Molecules Come From?
Many energy storage molecules are made of carbon, and carbon dioxide (CO2) surrounds us in the air. The presence of CO2 is a crucial element in creating energy storage molecules.
Plants are an excellent example of an organism that makes energy storage molecules, called a “producer.” A producer absorbs carbon dioxide molecules from air and water and combines them with the sunlight’s energy to create glucose and oxygen molecules.
As plants grow, they absorb more carbon dioxide and produce more oxygen while storing more energy storage molecules. That’s why trees are so good at absorbing carbon dioxide, emitting oxygen, and releasing a lot of potential energy as thermal energy when used as firewood.
How Much Energy Does Cloud Storage Use?
Another type of storage growing in popularity is cloud storage for our music, photos, files, and more.
Apple, Google, Amazon, Microsoft, and many other prominent names are all investing in cloud storage and “big data.” Such computing storage and information technology infrastructure require significant power at data centers.
A recent report by Bloomberg estimates data centers now account for around 1% of worldwide electricity demand. There are already companies, like the Green Software Foundation, looking at developing data storage programs that consume less energy.
Energy Storage Changing Energy Production and Consumption
Energy storage is already a significant player in the energy mix when including hydropower. Strip away hydro, and the energy storage sector is a tiny but growing industry.
The road to net-zero emissions by 2050 is not just about energy saving or energy reduction. Energy demand is increasing globally. It is also about capitalizing on the energy we already create and keeping it for when we need it, just like when we charge our laptops.
The challenge is to upscale energy storage quickly enough to make it more competitive in the international market. Government and industry-led initiatives will be crucial in transitioning from fossil fuels to renewable energy backed by energy storage. It’s simply saving solar power for a rainy day.
Customers can help, too, by switching to green energy plans that encourage the use of renewable energy. That way, we fully use every drop from these precious energy resources.
Brought to you by amigoenergy
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