Patricio flew to Iquique on June 8th, along with the supporting team members from Santiago: Lorenzo Reyes, already introduced in our previous post, who is the engineer in charge of the Huatacondo project; Bernardo Severino, an undergraduate student (now graduated) at the Electrical Engineering department who has been closely involved in the project; and Pablo Mendoza, Patricio’s younger brother, an undergraduate student at the Schoool of Veterinary Medicine of the University of Chile and enthusiastic volunteer who must also be credited for many of the beautiful pictures you see in the Microformer website.
Iquique is Huatacondo’s closest city with airport access, being located about 100 miles away. After the plane trip, the team drove a 4WD pickup truck for about three hours, crossing endless straight roads and astonishing landscapes of Atacama desert.
Huatacondo is located in the Andes mountains, about 2,200 meters above the sea level. It is one of the few fertile valleys in this region, being crossed by a relatively dry river. However, the invierno andino (Andean winter) provides enough precipitation to even cause floods in an otherwise dry climate.
Huatacondo has about 150 inhabitants. Its population is composed mainly by mining company workers and their families, although a few have stayed there after retirement. The amenities of the town include a community center, a soccer field, a preliminary school, and an emergency health care center, among others.
Originally, Huatacondo featured a diesel generator that fed the whole community with electricity, everyday from 2pm to midnight. Additional fuel allowance existed for special day events, such as religion-related celebrations. The diesel genset power plant was (and is still) located several hundred meters far from the houses. Next to the genset, the University of Chile developed the rest of the system that interconnects the solar panels with the existing off-grid electricity network, as part of the Energía Sustentable Condor (ESUSCON) project. With this, the power house is now expanded and hosts a 170kWh battery energy storage (BES) system and a 22kW PV solar panel farm. With the inclusion of these components, the community enjoys 24-hour electrification and a remarkable reduction of fuel consumption, due to the shorter genset operation daily cycle and improvement of its point of operation.
There also exists a wind turbine located 700m away (and 400m higher) from the community, which was initially interconnected with a low voltage transmission line. However, the voltage drop on the line was not acceptable, threatening a smooth and secure power transfer. This transmission line was upgraded to a Microformer system, using four units on each end of the transmission line. Due to the voltage limit on the transmission line (1000 volts), the Microformers were connected in series/parallel configuration, which cuts the secondary (high) voltage in half. However, the transformers have to be then derated to half the power. Therefore, the 4-Microformer bank on each end is rated 2kW, where each Microformer was originally rated 1kW.
The installation of the Microformers required a huge effort form the team, since each transformer, after the oil filling, weights about 10 kilograms, and needed to be carried up to the mountains. In addition, the process of mounting the Microformers on a pole is exhausting. The installation and commissioning took in total two days.
The Microformer line was first tested transmitting power from the community to the top of the mountain, where there exists a telephone amplifier and antenna, which provides the only telephone landline to the community. It is very importance for the community to have a working phone in case of emergencies. The Microformer serves then the battery charger of the telephone amplifier.
Since the wind turbine was not in operation at the time of the Microformer installation and commissioning, it was not interfaced with the grid. However, the point of connection to the grid that the Microformer provides is ready to be used by the wind turbine converter and any other device. For example, lighting could be provided at the wind turbine location if necessary.
Since the new transmission line carries high voltage, the operator of the Huatacondo grid was made aware of this situation, to avoid people climbing on poles or tapping the line to connect loads (as it was done in the past with TV antenna amplifiers).
It is expected to have the wind turbine working by the end of 2011, where the Microformer transmission line will be utilized bidirectionally. This is, it will provide energy to the telephone amplifier battery charger when the wind is absent, and will carry the energy harvested by the wind turbine to the rest of the grid.