Use of HDPE geocells to replace rip rap and reinforced concrete in superficial drainage structures in Photovoltaic Power Stations.

Currently, our society is showing a strong preference for the use of renewable energy sources due to its benefits in terms of contamination and generation of toxic gases or waste emitted to the environment, when compared to conventional sources of electricity generation. In Brazil and in the world, one of the most common is solar energy, converted into electricity on farms that group a large number of photovoltaic panels. The choice of the appropriate place for the implantation of these farms considers, among the requirements, places with high index of insolation, low humidity and long periods of drought, characteristic of regions located in the states of Bahia, Piaui or Minas Gerais. Unfortunately, these regions also have concentrated months of heavy rains, which generate great erosion problems due to the flow that forms on the large solar panels, which descends and “washes” the foundations soil, putting at risk the cementation of the solar capture structures. This problem needs to be treated with an appropriate piping and surface drainage system, but the ideal regions for the implantation of photovoltaic plants are also located away from cities or reservoirs able to provide resources for the deployment works, therefore, the construction of reinforced concrete channels, gabions or rockfills is extremely expensive, as well as complex in terms of construction and transportation. The present work will demonstrate how the use of high-density polyethylene (HDPE) geocells allowed the construction of low cost and very fast channels to be installed, in several of the largest photovoltaic works in the country, using cementsand mixtures or cement with soil. It will be presented extraction tests that show how the geocell interaction with filling material allows a shear failure of the inserted block in the geocell and not by flexion, as in the conventional concrete slabs, which allows the geocell system to dispense the use of steel of reinforcement, as well as construction joints and expansion / contraction, even with the use of depreciating materials for structural applications such as cement sand. Finally, we present the economic comparative between geocells and reinforced concrete that led the builders to prefer the system with geocells filled with mortar before conventional systems of low cost-benefit.