By Jack Shaw, senior writer and editor at Modded
Renewable energy has allowed the world to progress toward a cleaner energy future. However, variability is one downside of some types. Specific weather conditions can generate below- or above-average amounts of solar and wind power. Energy storage systems capture the excess for later, enabling people to use it during less productive periods.
Researchers, engineers and other concerned parties frequently investigate new storage possibilities, knowing that diverse options should raise people’s willingness to use renewable energy for the first time or expand their utilization. Explore recent examples of meaningful work to further renewable energy storage options.
1. Providing a Second Life for Used Electric Vehicle Batteries
Many renewable energy storage innovations involve building systems from scratch. However, some exceptionally creative and sustainable endeavors feature components people ordinarily discard or recycle. One example comes from the automaker Porsche, which has solely used renewable energy in its production facilities since 2017. Business leaders recognize the usefulness of energy storage products in industrial applications, mainly as they aim to maintain high productivity levels by reducing downtime.
The engineers who developed a new battery storage system for one of Porsche’s German plants tackled the growing waste generated by end-of-life products that further green energy. While exploring how to make the facility more self-sufficient and economically viable, they realized electric vehicle batteries from test cars would make suitable power sources.
The company previously sent them to recycling plants. However, this option presented a different possibility of strengthening the circular economy by keeping products in use longer and reducing environmental impacts.
Those building this stationery battery storage system incorporated 4,400 modules, dividing them into four containers. This setup provides a 5-megawatt capacity with a 10-megawatt-hour energy content. Users can also run it in a 20% overloaded state for short periods if needed.
This system activates during the facility’s peak loads to reduce them. Energy to power it comes, in part, from the plant’s 9.4-megawatt solar equipment. Engineers designed this storage solution to offer at least 10 years of useful life, emphasizing another circular economy focus. Additionally, people can replace individual battery modules to prolong functionality.
This approach to renewable energy storage is notable because it relies on the company’s internal resources. Rather than having batteries recycled by a third party, they remain intact and become important for keeping the plant operating smoothly during fluctuating renewable energy demands.
2. Integrating Bidirectional Charging Technologies Into Electric Cars
Some battery storage innovations use bidirectional charging. Such solutions can either receive power from the grid or send power back to it. Another fascinating exploration of how to tap into existing resources occurred when researchers examined using electric vehicles as mobile energy storage systems to support renewable energy infrastructure. If they had bidirectional charging capabilities, these automobiles could hold and release energy as needed.
The outcomes indicated this strategy could reduce dependence on stationary storage systems by 92% in the European Union by 2040. Additionally, it would enable a 40% increase in installed photovoltaic capacity. Researchers calculated that people could save up to 52% on their annual electricity bills with this option, such as by allowing their electric cars to take excess electricity from home solar panels when possible.
Electric vehicle batteries would also last up to 9% longer because they would stay in an optimal charge state rather than undergo repetitive cycles.
Charging options for EVs have already improved dramatically. Some fast-charging systems need only 20 minutes to replenish a battery. This innovation is another example of ongoing progress. However, even as the researchers confirmed that electric cars could offer an untapped battery storage solution, they recognized some challenges to overcome.
First, consumers need to see the value of this vehicle-to-grid option and purchase bidirectional components and home charging equipment. However, researchers believe that is a relatively small hurdle because electricity bill reductions would quickly offset those expenses. Adapting all-electric vehicle chargers to support bidirectional technology is a more daunting aim requiring legislative support. However, lawmakers could take a decisive step by finalizing bidirectional charging strategies.
3. Designing a Modular Dam to Support Renewable Energy Storage
Renewable energy professionals increasingly focus on hydropower solutions, recognizing their numerous potential benefits. For example, the plants can last for decades once built, making them long-term solutions. Also, pumped hydroelectric storage accounts for 94% of the world’s retained electricity. That high adoption rate suggests industrial decision-makers already view this option as trustworthy.
Researchers have developed a modular steel buttress dam system to address energy storage issues that have previously made it more challenging to implement renewables into the more extensive power mix. Their innovation enables the efficient construction of paired reservoir systems capable of grid-scale energy retention and generation.
It uses water’s gravitational potential energy as electric-powered pumps push the liquid from a lower-elevation reservoir to a higher-elevation one. It also capitalizes on low-cost, off-peak power, making the operation as economical as possible.
Stored water returns to the lower reservoir during high electrical demand, making the turbines produce more power. This value-creating system then provides energy when electricity prices are steepest, eliminating renewable energy’s variability and saving money.
Additionally, this system relies on closed-loop pumped storage hydropower. Researchers acknowledged that numerous factors have historically discouraged people from developing these facilities. Modern pumped storage hydropower plants have a round-trip efficiency of nearly 80%, but construction has occurred on only two moderately sized facilities in the United States over the last 20 years.
This modular option could reduce building challenges and costs, mainly because people can transport the system’s steel components on flatbed trailers, facilitating the creation of buttress dams up to 40 feet high. Those water impoundments could store hundreds of thousands of megawatt-hours of energy to support the grid during peak demand or provide ancillary services for better stability.
4. Turning an Industrial Waste Product Into a Storage Option
Many battery-based energy storage systems rely on mined metals. The significant geographic concentration of these resources makes them challenging to source. Additionally, the associated practices have a long history of environmental and human rights-related downsides. These realities make researchers eager to find more suitable alternatives.
A team recently converted an organic industrial-scale waste product into an efficient energy-storage mechanism they hope to eventually use for grid-scale applications. Their work centered on redox flow batteries, which have already gained significant research attention. However, this effort was the first of its kind because it used a waste molecule called triphenylphosphine oxide.
Experiments showed this groundbreaking option had a high energy density that edged it closer to matching its metal-based battery counterparts. To achieve the necessary stability, the researchers drew inspiration from a 1968 paper describing phosphine oxide electrochemistry. This content paved the way for devising a strategy to keep the electrons tightly packed in a solution and prevent them from losing storage capacity over time.
The group confirmed that the battery performed well through 350 charge cycles, losing negligible capacity during those tests. They also noted that their molecular engineering approach overcomes the instability challenges that have historically made reduced phosphine oxides unsuitable for battery storage applications.
Additionally, since this work concerned converting waste compounds into sustainable power options, it could reveal similar avenues for other researchers, encouraging more groups to assess uncommon or previously unused possibilities for their innovations.
5. Developing Additives to Improve Battery Performance
Some groups investigating battery storage systems to further renewable energy utilization have prioritized solving known problems. One group created an additive that addresses many issues with bromide-based aqueous flow batteries. Engineers and other professionals see their potential and simultaneously recognize their electrochemical downsides. Fortunately, this water-soluble creation solves many of them.
Aqueous flow batteries use ions dissolved in water, eliminating many of the fire risks associated with the lithium-ion power sources commonly used for renewable energy storage. The most commercially developed flow batteries are vanadium ion-based, but that characteristic introduces supply chain and cost-related challenges. Bromide-based versions could be more accessible, but their tiny ions can penetrate electrode-separating membranes, reducing efficiency. These power sources can also produce toxic gas, interfering with their reliability.
However, this team used molecular design to find more than 500 organic molecules that became potential candidates for an additive to address these matters. They then synthesized and tested 13 of them, resulting in several additives that enhance the battery’s performance while mitigating the known issues.
Tests showed batteries containing an additive functioned without decay for two months. In contrast, those without it typically failed within a day. Knowing how to enhance longevity in commercial products will be essential since most people investing in green energy storage expect to use the products for at least a decade.
Additional plans for this work include a deeper investigation into the associated science and tests to probe the additives’ commercial viability.
Creating Sustainable and Dependable Solutions
Many people are interested in making sustainable changes to their energy use habits, including increasing their reliance on renewables. However, they will be much more likely to transition to green power and scale up those efforts if they trust that energy is available when needed. Renewable energy storage meets that requirement, and these examples show the ingenuity industry professionals use when assessing possibilities and tackling challenges. Their findings will enable progress, even if some attempts are not commercially viable.