Renewable energy is a necessity in the face of climate change, as industries and communities are increasingly adopting clean sources, such as solar and wind power. However, a major challenge is their intermittency; the sun does not always shine, and the wind does not always blow. This variability creates a gap between when energy is generated and when it's consumed, making it difficult to use its full potential.
A major hurdle is the significant energy demand for heating and cooling buildings and industrial spaces. In buildings, this can represent as much as 70% of total consumption. Similarly, industries like food processing need a constant supply of thermal energy for operations such as cooking, preservation, and cooling. This high demand drives up operating costs and perpetuates a dependency on polluting energy sources.
Energy storage is essential for bridging the gap between generation and consumption. Currently, the most common methods are electric batteries and sensitive thermal systems (like water tanks). The latter are more affordable but have limited capacity. Batteries offer greater storage but are too expensive for mass implementation.
Storing Surplus Energy
The solution lies in developing more efficient, affordable, and large-scale technologies. Thermal storage systems, in particular, are needed to conserve surplus renewable energy and make it available when demand is high.
To solve this issue, Dr. Diego Vasco of the Department of Mechanical Engineering at Usach is developing a system to store surplus renewable energy as heat and cold. This stored energy could then be used for air conditioning, helping to reduce energy consumption in buildings and industries. The goal is to create a more efficient, affordable, and environmentally friendly solution for utilizing solar energy.
Dr. Diego Vasco explains that the research aims to develop an "intermediate solution" that enables the more economical storage of large quantities of energy, making it a viable alternative to wasting excess renewable power. He posits that storing energy in the form of heat or cold is more cost-effective, which is why the team identifies "great potential in thermal systems, especially in latent heat storage."
To make this possible, the project is developing a system for thermal energy storage. It uses specialized tanks filled with phase change materials, which are compounds that transition between solid and liquid states at a specific temperature. This enables them to absorb or release significant amounts of latent heat, preserving thermal energy more effectively and for longer durations than conventional methods.
Organic materials
The researchers explained that they will primarily use organic phase change materials, particularly vegetable oils (Bio-PCMs), citing their low environmental impact and thermal stability. They are also evaluating inorganic materials, such as metal oxides, for their superior energy storage capacity. However, the team favors organic materials for this system due to their enhanced safety and sustainability, which mitigates the corrosion issues associated with inorganic compounds.
The research also incorporates nanoparticles to improve the materials' performance by increasing their heat conductivity. This enhancement allows the system to heat and cool faster while storing energy for longer. As a result, the system can operate more efficiently and adapt better to a building's air conditioning demands.
"We really need the chemical part, because we are working with materials that must be modified to improve their thermal performance. We have to characterize them, understand how they behave when combined with nanoparticles, and make sure they work well within the entire system," says Dr. Diego Vasco.
According to Dr. Diego Vasco, the chemical component is essential. "We are working with materials that must be modified to improve their thermal performance," he stated. He added that the team's work involves "characterizing them, understanding how they behave when combined with nanoparticles, and ensuring they function effectively within the entire system."
"Our goal is not only to develop a technology that serves various productive sectors but also to demonstrate the feasibility of more effectively utilizing renewable energy and providing practical solutions to societal needs," concluded Dr. Vasco.