The great challenge for renewable energies is that, for the most part, they do not offer a constant flow of energy.
Unlike, for example, a nuclear power plant, in which generation only depends on keeping the reactor running, the energy sources that nature offers us, such as the sun, wind or waterways, are not always constant. While there are days when they can produce above demand, a cloudy day or with little wind can cause the generation level to decrease.
Hence, it is key to be able to capture and store the energy that is produced in order to be able to put it later into the electricity grid. This requires batteries that, in the case of solar energy, continue to provide energy at night after having accumulated it during the day.
The role of batteries in energy storage
Thus, the development of new and better storage methods is also a necessary part of the development of renewables, with the deployment of batteries being the most widely used, especially lithium-ion batteries, which allow the efficient completion of generation cycles and the transport of electricity.
The batteries offer a bidirectional flow of energy, almost immediate reaction and a great capacity to deliver and receive energy according to the needs of the network and the circumstances of the generation.
For this reason, the Government has recently approved an Energy Storage Strategy, which aims to have a storage capacity in Spain of 20GW in 2030, and 30GW in 2050. That is, equivalent to three nuclear power plants operating at full performance.
Battery application for energy storage in other businesses
These technologies can also be applied in new business niches, such as electric mobility, in which more and longer-lasting batteries are being sought, or in the building sector through self-consumption of electricity and the storage of thermal energy, allowing the appearance of new solutions in buildings, which also serve as an indirect structural measure against energy poverty.
Also, it can be used in industry, having a strong potential for self-consumption with storage, energy integration, decarbonization, and processes that use heat and cold; as well as in other sectors through self-consumption applications, among others.
Types of batteries and their uses
In addition to electrochemical batteries, such as lithium batteries, thermal batteries can also be used (because they store energy in the form of heat), or renewable hydrogen batteries.
These batteries increasingly seem to be the future to store energy from renewable sources, in electrochemical cells that use the most abundant element in the universe (hydrogen) to store and generate energy, leaving water vapor as the only residue.
Hydrogen can be produced by electrolysis of seawater, for example by applying electricity obtained from the wind, the sun or the tides, to separate hydrogen molecules from oxygen molecules and introduce the resulting hydrogen into a cell divided into cells that allows it to respond to high energy demands for much longer than conventional lithium batteries.
Hence, its applications for heavy transport, such as trucks or ships, are being considered, as well as another method of storing electricity in large terrestrial hydrogen cells connected to the electricity grid.
Challenges and perspectives of batteries in energy storage
Meanwhile, work continues on the development of new, cheaper, more efficient electrochemical batteries that generate less environmental impact.
The challenge with current lithium batteries is to achieve faster charges, longer duration and less degradation of the battery that prevents them from having to be replaced often, with the consequent expense and waste management.
The growing demand for renewable energies, electric vehicles and the search for self-consumption by a greater part of people, has notably boosted research into new types of batteries, some of which offer very promising results, such as a developed lithium-sulfur battery by an Australian university.
This type of battery would be more stable than current lithium batteries and would allow a vehicle to travel more than 1000 kilometers on a single charge, almost double what is currently possible. Or, in the case of a mobile phone, give it a range of five days.
Car manufacturers, in turn, are still looking for ways to improve and make existing batteries cheaper. Thus, the industry leader, Tesla, is perfecting its lithium batteries by recycling metallurgical silicon.
Toyota is developing robust batteries that are stronger, lighter, and less vulnerable to fire than today’s batteries. The Japanese manufacturer ensures that this new type of batteries can be charged in 10 minutes and offer autonomies of up to 500 kilometers.
But beyond vehicles, these new types of batteries can be used in homes, to free us from the constraints of peak hours and off-peak hours of the electricity bill.
Or in large onshore facilities, such as those that are beginning to exist throughout Australia, where enough energy is accumulated to avoid polluting backup plants, such as coal or gas thermal plants.