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Arriaga M.,Electric Research Institute of Mexico
Renewable Energy | Year: 2010

This paper presents the pico-hydro development status in Lao PDR and introduces the Pump as Turbine (PAT) concept as an alternative for isolated communities (40-500 people). The intention is to provide a long-term reproducible system for communities where pico-hydro propeller turbines are insufficient and proper turbines are expensive. This approach presents a high quality and cost-effective solution for rural electrification which can be installed, commissioned, and maintained by local staff and villagers. Furthermore, a 2 kWel PAT-scheme is proposed for a community in the Xiagnabouli province and considers power generation alternatives, sizing, asynchronous motor simulation, civil works, cost estimation, and social aspects. © 2009.

Gomes C.,University Putra Malaysia | Diego A.G.,Electric Research Institute of Mexico
Safety Science | Year: 2011

This paper provides comprehensive analysis on the lightning protection scenarios in 48 communication and broadcasting towers situated in similar isokeraunic contours in Sri Lanka at 79°-81° East and 5°-10° North. The investigation has been conducted to study the hazardous environment created on the tower and in the neighbourhood in the event of a lightning strike to the tower. The results show that a direct strike to an antenna structure in a metallic tower is rare irrespective of the presence of an air-termination or a down conductor. However, side flashing or arcing to antenna structures is highly possible once the air-termination and/or down conductor is installed and attempts are made to insulate the system from the tower. The outcome also shows that equipotential bonding of the grounding system, a distributed grounding network including a ring conductor and a suitable system of surge protective devices play a much vital role in lightning protection of equipment and safety of people compared to the effects of simply achieving a low grounding resistance. However, in the absence of such integrated, distributed and equipotentialized grounding system, a high value of ground resistance will sharply increase the possibility of accidents and damage. Considering the observations of the investigations into account we have designed a concrete embedded grounding system for tower sites at problematic locations. Finally, the scenarios for safety management at telecommunication tower sites have been discussed. © 2011 Elsevier Ltd.

Hernandez-Escobedo Q.,University of Veracruz | Saldana-Flores R.,Electric Research Institute of Mexico | Rodriguez-Garcia E.R.,University of Veracruz | Manzano-Agugliaro F.,University of Almeria
Renewable and Sustainable Energy Reviews | Year: 2014

Mexico has installed less wind power compared to the other North American countries. Renewable energy sources only account for 3% of the energy mix in Mexico. The U.S. states bordering Mexico, namely Texas, New Mexico, Arizona, and California, have good wind power resources. Among them, Texas has the highest installed wind power capacity of 10.34 GW. The wind resources in these bordering states indicate that the wind energy resource in Northern Mexico must be assessed; thus, the spatial and temporal information about the wind energy resource was studied. The daily pattern of the wind speed, one per state studied, was obtained. The wind speed was found to exhibit a pattern; it increases from 4 pm until 6 am the following day. The main conclusions are that the state of Tamaulipas has the highest Wind Power Density (WPD) of 1000 W/m2 during September and October, but the north of Nuevo Leon has, in a large part of its territory, an annual WPD greater than 103 W/m 2; each state has 1700 useful hours of wind speed above 3 m/s. Northern Mexico has some zones with excellent wind speed as well; the states of Chihuahua, Coahuila, Nuevo Leon and Tamaulipas have a wind speed of over 4.51 m/s across nearly their entire territories. Because Mexico in recent years has been starting to exploit renewable energy sources, the government has mandated energy reform, which improves the conditions for investment in wind energy in Mexico. © 2014 Elsevier Ltd.

Verma M.P.,Electric Research Institute of Mexico
Revista Mexicana de Ciencias Geologicas | Year: 2013

A computer program, GeoSteamNet, for the numerical simulation of steam transport in geothermal pipeline networks is written in Visual Studio .NET. The program considers (a) internally consistent thermodynamic properties of water, and (b) a numerical algorithm based on the principles of conservation of mass, linear momentum (Newton's second law), and energy (the first and second laws of thermodynamics). Instability in the algorithm is observed as a consequence of ideal gas behavior of steam at low pressure, which is resolved by setting the lower limit of pressure to 2.0×105 Pa. An ActiveX control, SteamTablesGrid, is used to calculate the thermodynamic properties of water. A study of the interrelationship among thermodynamic state variables like temperature, pressure, volume, internal energy, etc. indicates the internal consistency in the thermodynamic properties of steam only. The application of GeoSteamNet is demonstrated in the management and optimization of steam flow in a hypothetical geothermal power plant with two wells and one production unit. GeoSteamNet calculates all the parameters like fluid velocity, different types of energies such as heat loss, mechanical (kinetic and potential) energy, thermal energy, frictional energy, and total energy. Thus, the mass, linear momentum and energy balances at each nodal point in the pipeline network are used to validate the algorithm. Additionally, the computer program can also be used efficiently in the design and construction of geothermal pipeline network.

Aviles J.,Instituto Mexicano Of Tecnologia Del Agua | Eduardo Perez-Rocha L.,Electric Research Institute of Mexico
Soil Dynamics and Earthquake Engineering | Year: 2011

This paper investigates the applicability of global ductility in the conventional design procedure of structure-foundation systems under earthquake excitation. For a bilinear elastoplastic model, an equivalent ductility factor for the combined structure and foundation is derived, which can be used in conjunction with the enlarged period and increased damping due to soil-structure interaction (SSI) to determine the design strength. A geometric transformation rule for predicting the ductility demand developed in the structure alone from that experienced by the interacting system is also derived, without the need of computing the rigid-body motion of the foundation. To validate this practical approach for assessing both inelastic strengths as well as ductility demands, a number of numerical results for different system parameters and earthquake excitations are provided. The effects of principal parameters involved are also examined. © 2011 Elsevier Ltd.

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