It’s estimated that 22 million people or 6 million households in Latin America lack access to electricity. Solar powered mini-grids, micro-grids and off-grid standalone systems are offering solutions to power basic human needs provided by water pumps, lighting, cooking facilities and more. Here we look at a range of off-grid solar solutions, from mining to street lighting to basic home electricity.
Solar replacing diesel in mining industry
The mining industry is increasingly turning to solar power to meet its high energy needs in very remote locations, where they often have no grid access. Replacing diesel generators and augmenting unreliable grid power with local renewable energy sources has the potential to greatly reduce mining operation greenhouse gas emission as well as costs. More mine operators across Central and Latin America are increasingly turning to solar electricity to take advantage of the regions’ abundant sunshine and harvest electricity locally, cleanly and more cheaply. Added benefits are the reduction or elimination of production delays due to load shedding and power outages.
One firm specializing in renewable applications for mining is Trailers RD-Minas. Their engineered solutions are renowned for improving worker safety and performance while also reducing maintenance costs. Mobile radio repeater trailers provide customers with real-time view of the status of their solar panels, batteries, operating cycle and position, at remote locations. This greatly facilitates maintenance and avoids unnecessary shifting and/or allocation.
These specially designed and constructed trailers feed into the AC network and are mounted with a generator, air conditioning thermal insulation and battery banks.
A typical trailer’s chassis can accommodate 8, 14 and up to 20 deep cycle batteries rated at 110AH to provide sufficient autonomy in remote applications. The trailers used Morningstar solar charge controllers, specifically the TriStar MPPT-60, TriStar Meter-2, ProStar MPPT-40 and the SunSaver-MPPT-15.
Lighting for safety
For on-site lighting, mining operations use mobile light trailer towers with high-efficiency LED spotlights powered by batteries recharged with solar panels and sometimes a wind turbine powered generator. These lighting trailers are automatic, and do not require an operator to turn on at night or turn off in the morning. When fully automated, a tower can operate for 28 hours without incident of sunlight, over a day of autonomy. They are ideally suited for use in mining, maintenance stations, workplaces and other locations that require illumination for safer work at night. Unlike conventional diesel lighting trailers, Trailers RD-Minas’ designs do not require fueling, filter replacements, belts, lubrication and other maintenance items—or even frequent bulb replacements, since the LED spotlights can last about 50,000 hours.
Illuminating the superhighway with solar
The Arco Metropolitano is a 145 KM arch of highway in the state of Rio de Janeiro stretching from the port city of Itagui to Duque de Caxias, a commercial and manufacturing center that boasts one of Brazil's largest oil refineries. The arch skirts the booming metropolis of Rio de Janeiro city, providing a vital connection to the five major highways that crisscross the state.
One of the most strategic highway projects in Brazil, the Arco Metropolitano diverts commercial traffic out of the congested roads of Rio de Janeiro city, while serving as a lifeline to the less developed regions of rural Rio de Janeiro state. Commercial trucks transporting goods throughout the state have reduced transportation time by half, and development along the highway has brought economic growth to regions previously cut off from the city center.
Hazardous weather conditions and high crime made driving on the highway at night difficult and dangerous. To keep the highway open, the government needed a reliable lighting solution that would provide round-the-clock illumination on the most trafficked and dangerous stretches. In response, state government of Rio de Janeiro facilitated the largest solar highway project ever attempted in Brazil, and one of the largest in the world, a project locals called the Solar Superhighway. The project called for more than 4,300 free-standing streetlights to be installed along a 73 KM stretch of the highway connecting to Itagui, a critical port entry.
Japanese electronics firm Kyocera Solar, Inc. partnered with a Brazilian engineering company Soter to develop and install a street lighting system capable of producing 2.8 GWh of solar energy per year without burdening the already fragile local energy grid. The Kyocera streetlight kit creates a stand-alone streetlight independent of the local grid, or other supplementary energy sources. To accomplish this, the system depends on a lead battery system connected to a charge controller, capable of storing up to three days’ worth of energy. The Morningstar TriStar MPPT-45 serves as a critical component for this single-source energy solution.
Each streetlight kit, capable of producing more than 2.8 GWh of solar energy per year, consists of:
- Morningstar TriStar MPPT-45
- Four 240 Ah/12 Vcc batteries
- 150 W LED lamp
- Three solar modules
- One photocell
- One pole with mounting structures
To operate, the batteries are connected to the TriStar MPPT-45 and store solar energy during the day. Once the photocell detects that light levels have fallen and LED lamps are needed, the lights automatically switch on. The system is capable of storing enough energy to power a streetlight for up to three days without sunlight.
Solar home systems
In November of 2003, 10 million people residing in Brazil’s rural areas were without access to electricity. With approximately 90% of them living below the poverty line. That meant they lived without basic amenities others take for granted, such as electronic devices, refrigeration, and lighting, in homes, schools and health clinics. Worldwide, this lack of electricity in rural areas is the single biggest impediment to economic growth and contributes to isolation for many communities. For this reason, many countries have adopted ambitious rural electrification programs specifically designed to eradicate this “electrical poverty and lift rural residents into a higher standard of living than previously possible."
The “Light for All” program was launched in 2003 by the Brazilian federal government. Coordinated by the Ministry of Mines and Energy, the program was established to deliver electricity to families in rural areas.
"The success of the ‘Light For All’ project is paramount to the progress and prosperity of the citizens of Brazil. The SureSine’s [inverter] rugged enclosure with no internal cooling fan ensures long-term reliability even in the harshest conditions,” said Sergio Beninca, President of Kyocera Solar Brazil.
Besides covering the equipment costs and installation fees, the program provides citizens with the necessary materials and training to operate and maintain the renewable energy installations in their communities.
The electrification program also reaches indigenous areas, including those difficult to access in the Amazon region. Challenges include transporting heavy equipment such as electrical mounting poles on boats to less accessible regions, as well as passing electrical cables through rivers.
To convert the solar-generated electricity to AC and deliver off-grid AC power to run electrical loads in rural households in remote locations, 20,000 SureSine inverters from Morningstar were installed along with SunSaver solar controllers in systems with 160W solar photovoltaic modules. The SureSine inverter is a sealed design that requires no cooling fans. It’s ruggedized and encapsulated to withstand harsh conditions, as well as fault tolerant with built-in protection circuitry better able to resist damage caused by installer or user error—an important consideration in remote locations.
Following these solar electricity residential installations, it is estimated that 81% of these families who were now able to access AC power purchased new TV sets. In addition, 71% of them bought refrigerators and 62% acquired cell phones. For the first time, many rural residents experienced the relative luxury of being able to read at night, watch a TV show, listen to music on the radio or enjoy a cold drink.
The comprehensive Light for All electrification project enhanced and improved public services, education and welfare, employment and income. By May 2016, 15.6 million Brazilians had benefited from the program and over 485,000 jobs were created. This unqualified success led to the extension of the program into 2018 with the goal of bringing another million citizens literally out of the dark.