64 percent of the electrical energy in Colombia is generated by water. Unlike fossil fuels, the second most used source in the country, electricity generation does not produce toxic gases, but the high dependence on this resource results in vulnerability during times of drought or scarcity.
The daily solar radiation average, energy produced by the sun through electromagnetic waves, is 4,5 kilowatt-hour per square meter (kWh/m2) in our national territory. This represents great energy potential compared to countries leading the exploitation of this resource. Such is the case of Germany that generates an average of 3,2 kWh/m2.
The Universidad EAFIT Helium project offers four technology solutions of solar energy to Colombian urban and rural areas that will help maintain the balance with other types of energy and that will benefit from the climatic conditions of the country.
A brick that transforms solar energy into electrical energy, a system of panels capable of self-positioning to track the path of the sun, a charging station for bicycles and electronic devices, and a collecting pipe system that transports heat to drying rooms are the four sustainable solutions developed.
The valuable contribution of these initiatives is remarkable since they seek to reach areas that are not connected to the national electricity transmission system and where diesel fuel plants are currently being used to supply power.
Applied Science
These energy alternatives at Universidad EAFIT date back to 2013 when an interdisciplinary team of researchers, members of the research groups of design engineering (Grid), Applied Optics and Tecnologías Marte spin off and Dynacad, was formed to discuss aerospace related topics.
With this objective in mind, they identified the need to learn about solar energy. They also found that even though this was a field to be explored, it had a latent market. This is how the applied science initiative called Helium, which lasted 15 months, and won the first call by Ruta N InLab2 Market and Centro de Tecnología de Antioquia that sponsor research on global projection, aimed at strengthening the energy health and ICT sectors.
A brick that generates electricity
The use of photovoltaic solar energy (transformation of solar energy into electrical energy) in urban areas has been limited to roofs, since the space to install the panels is reduced and competes with construction or cultivation.
Even though the possibility of covering vertical areas (facades) with standard photovoltaic panels is functional regarding technical terms, it does not provide much freedom in terms of aesthetics and it adds weight to the structure in general.
However, from workshops carried out with architects, industrial designers and engineers, Helium researchers concluded that a concept derived from the panel´s basic unit (photovoltaic cells) should be developed and become a supply in the construction field. This is how they proposed to build the facade walls of houses and buildings with solar bricks.
Regarding this alternative, Alejandro Velásquez, faculty member of the Product Design Engineering program, states that 40 solar bricks could provide light to an average house, which constitutes 10 percent of the total energy consumption. Likewise, its external side will allow for as much photovoltaic material as lighting elements. This makes it possible to light the building facades with energy generated by them.
According to the researcher, the fact that the solar panel price gradually drops –in 40 years the solar watt went from 76 dollars to 40 cents, makes this type of project financially viable, even if they are put in a vertical position and only receive sun light for half a day.
Devices that track the sun
To install solar panels in semi-urban and urban areas, a system of solar tracking or tracker was proposed, which unlike conventional systems, is capable of self-positioning.
“We are thinking of turning it into a kit any person can buy and install easily. It is an intelligent system that through a Global Positioning System (GPS) knows its location and the exact time. The system has a digital compass that indicates north. Through this information it is possible to identify where the sun rises so it follows its path”, explains Mauricio Betancur engineer at Tecnologías Marte.
The prototype tracker has two degrees of freedom which means it can rotate and travel. The device has 2.5 kilowatt-hour installed capacity, an average house requires twice as much per day. It generates 33 percent more energy than the static panels. The system includes Software that provides the user with a web report on the amount of energy being produced, the quantity stored and the price indicators in the power exchange.
As a complement of this front line of work, a solar charging station emerged. It consists of six 250-watt, see-through solar panels with capacity for charging four electric bicycles and outlets to connect electronic devices such as mobile phones, tablets or computers. In order to efficiently use the energy of the sun during the day, the system has a mechanism programmed to look east in the morning, position horizontally at midday and relocate west in the afternoon.
Thermal energy collectors
A cloth-drying room that uses heat flow was built as a solar thermal energy proposal. Tests with Fresnel lenses and large parabolic dish mirrors (1,80 meters) to concentrate heat were initially carried out. However, efficiency reached temperatures as high as 1,500 degrees centigrade that became a risk factor for buildings.
“So, the option was to use pipes containing liquid to capture the heat produced by solar radiation and transport it by conduction into a metallic bulb which finally contacts a convection system that generates hot-air that is used for drying,” explains José Ignacio Marulanda, faculty member of the School of Science.
Under normal conditions, inside the laundry room of an apartment, 6 soaked towels take around 17 hours to dry. Using this system and under good solar conditions, the same amount of towels would only take four hours, states Marulanda.
From the lab to the market
In the Helium project there are no double roles: EAFIT’s Aplied optics research group takes care of the solar radiation and analyzes efficiency, Tecnologías Marte´s mission is the development of the electrical component and the software, Grid –whose members have experience with Primavera, the solar car– provides the design, integration and product language; finally, Dynacad takes care of the product scalability.
Researchers are currently focused on the solar brick encapsulation and structural design for validation and subsequent entry into the market. “Customers are interested in having a complete and intuitive-to-use product. The capsule must be held firmly on the facade. It also requires some optical characteristics that allow the transmission of solar energy into the cell. A connection system is also a must and it should be resistant since this will be construction material,” explains Mario Betancur, Dynacad engineer who adds that this process is vital to launch this product to the industry.
Seismic resistance tests will be carried out and a house will be built in association with AIA, a construction firm, so that the solar brick is validated by all the parties engaged in the construction process: from the architect, to the engineer, the worker and the electrician to the final user. To obtain the funds for this stage of the project, Helium applied for the 700 call offered by Colciencias for product validation.
Helium was supported by Corporación Tecnnova to formulate the marketing strategy, value proposition and the business model. Currently, with the support of the Centro para la Innovación, Consultoría y Empresarismo (Cice) of EAFIT, Helium is consolidating its business unit on solar energy technology to become a university spin off.
How to obtain energy from the sun
Solar radiation is the energy from the sun received through electromagnetic waves that can be converted into photovoltaic or thermal energy. The first consists of transforming the solar energy into electrical energy through the use of solar panels, which are a group of cells capable of capturing the sunlight and transforming it into electricity. The second one is using the energy of the sun to produce heat. For more information contact:
Alejandro Gómez Valencia
Journalist - EAFIT Information and Press
Phone: 2619500 Ext. 9931
Electronic Email: jgomez97@eafit.edu.co