Unai Arrieta, Trama TecnoAmbiental S.L. (TTA)
PV Microgrid with Energy Management Meters Power a Remote Village of 20 Homes without Diesel backup
Trama TecnoAmbiental S.L. (TTA) has implemented in 2012 a PV microgrid with energy management meters which powers a remote village of 20 homes without diesel backup in Las Balsas community, Parroquia San Gregorio, Muisne, Esmeraldas, Ecuador. The total project budget had been approximately Euro 60,000.
TTA is an international consulting and engineering firm working since 1986 in the field of renewable energies. TTA specializes in distributed generation through renewable energy sources (RE), energy management and efficiency, rural electrification, self-generation, integration of RE in buildings and sustainable architecture, as well as specialized training, education and technological development related to its activities. In rural electrification, TTA has been involved in studies, policy and implementation in many developing countries, especially RE microgrids.
The main objective of the “Fostering of rural development in communities of Esmeraldas project”, in Ecuador (FOMDERES), has been to provide modern electricity services through a solar microgrid generation to two communities in the province of Esmeraldas in Ecuador. Phase I (2005) consisted of electrifying the community called “La Y” providing access to 19 families, while Phase II (2012) reached 20 families of the community of Las Balsas. Specifically the project aimed at:
• Providing 24h access to electricity to the community at standard AC;
• Improving the socio-economic development of community through enhanced and affordable and high-quality energy services;
• Introducing and validating the concept of Energy Daily Allowance (EDA) and
• Using amorphous-silicon (a-Si) PV modules to validate their efficiency in tropical climates
The access to the remote community is cumbersome, taking up to four hours of combined walking and horse-riding. Locally generated electricity is thus the most feasible solution. Due to the impact on the project’s financial sustainability, ensuring that a long-lasting battery is operational over its lifetime is necessary. Besides, the energy supply depends on resource availability and the technical conditions of the area and thus ensuring that the limited solar resource is shared without conflicts and ensuring service reliability is the main challenge. The energy management provisions in place using Electricity Dispensers allow for a rational electricity supply and ensure that equipment (including batteries) operates within safe and designed technical thresholds. The community has a nucleus population of 12 families, plus eight more disperse households, besides communal uses. To reach all dwellers a combination of technical solutions was implemented through:
• one solar PV micro grid to supply 12 interconnected families and communal services,
• eight individual installations for the houses located further from the nucleus.
All users remain under the same operation scheme, which eases the O&M of the system and is not exclusive to the village nucleus.
Grid extension costs are too high for the level of energy demand. In the case of Las Balsas, the remoteness of the community justified harnessing solar energy for electricity generation.
With a mixture of clustered and scattered buildings in the village, the solution is based on a combination of a solar PV microgrid and individual PV micro power plants under the same operation scheme. Thus, electricity is supplied to households and communal services like street lighting, school, and community house. TTA’s award winning Energy Dispensers are used with a project-tailored tariff system to ensure the energy usage is according to the resource availability and the technical conditions. In the microgrid, a single 9.2 kWp PV generator (without diesel generator backup) supplied a DC coupled micro power plant with a 107 kWh battery storage and 7 kVA battery inverter, for 12 households and communal services. The eight solar PV individual installations had each 384 Wp, 3.2 kWh storage, and a 650 VA inverter. All consumers are supplied with 120 Vac electrical energy. The system is managed and operated by the community which created a Rural Electrification Board, which is composed of community members. Besides the renewable energy solution, the Electricity Dispenser meter was essential to manage each single user electricity consumption for the microgrid and individual installations and ensure an adequate energy daily allowance. Finally, local staff were trained to do the first-level maintenance.
The project was financed by a grant from the Municipality of Barcelona, Spain, and executed by the Spanish NGO SEBA, the local counterpart FEDETA and technology partner TTA. Operational costs were covered with tariffs. Tariffs were flat rate, fixed for each consumption tier (in the microgrid, between 1,000 Wh/day and 1,650 Wh/day for households; 550 Wh/day for the individual PV systems) pre-contracted and agreed by the community. Electricity Dispensers designed by TTA offered dynamic energy management.
Despite being grouped and scattered houses, all community members and communal uses were provided with access to affordable electricity, under the same tariff and management scheme. Electricity Dispensers with management of energy and power available to users allowed for efficient use of energy and control within the microgrid and also assist throughout the learning process of users. The Ministry of Energy in Ecuador has replicated the microgrid model in other regions using these components.
The key aspects of a sustainable and durable electricity service were:
• Logistic costs and challenges needed to be taken into account, especially material transport to remote locations.
• Successful implementation required user involvement and commitment to anchor the sustainability of project into the existing socio-cultural structures, encouraging social dialogue and communications among the community members.
• There was a right balance to find between the ability and willingness to pay by potential users, and the sustainability of the electrical services business