Researchers claim PV near railway tracks is technically feasible

An international team has conducted a technical and economic analysis to assess if deploying PV systems between or close to railway tracks is a viable option for rural applications and has found that this heavily criticized project typology may not only be technically feasible but also commercially attractive.

The main criticisms made of this approach relate, in particular, to two primary issues that may affect the performance of the solar panels – hard soiling and strong mechanical stress caused by the passage of the trains above the modules – two factors that could significantly reduce the system’s lifecycle and performance.

The scientists were aware of these risks and said that in Bangladesh, however, rail tracks are commonly built on soft alluvial soils that generally attenuate the vibration amplitude created by passing rolling stocks.

The scientists investigated, in particular, the feasibility of a net-meter-supported mini-grid solar photovoltaic power plant located near the nearside of the railway track in Bangladesh. They assumed a 128 kW array to be deployed alongside the rail track in the Bonomala region of Tongi in Gazipur, Bangladesh, with the distance between the rail track and the panel-bearing racking system pole being 3–4 meters.

The surrounding area has potential loads such as an 18.4 kW deep-tube well, two 5 kW shallow machines, a 35 KVA-driven poultry farm, and a 50 KVA-driven dairy farm. “Furthermore, a village market is surrounded by over a hundred families,” the researchers stated. “So, more than 100 kW of load demand exists.”

For the modeling, which considered solar panels, inverters, meters, wires, power requirement, output power, performance ratio estimation, meteorological data for the selected area, and tilt angle optimization, the scientists used the PVsyst software.

“The 128 kW power plant requires 342 solar panels racking on two or three rows of mounting systems alongside the railway track; thus, a total of 623 m² of state-owned railway land is required that would be utilized both for transportation as well as renewable power generation,” they explained. “Furthermore, as the dimensions of the module are 1,755 mm x 1,038 mm x 35 mm, a 1.821 m² area is required for racking every single module.”

For the PV system, the group assumed a tilt angle of 20.8 decrease, a module output of 375 W, three 33 kW string inverters, and a southern orientation. Their analysis also took into account a 1% array soiling loss, a 2% module mismatch loss, a 1% light-induced degradation loss, and other loss fractions such as string mismatch loss, module degradation loss, and DC wiring loss. Capex was estimated at $124,688 and opex for annual O&M activities was estimated at $4,748.

The scientists found that the system has a performance ratio (PR) of 77.3% and a levelized cost of energy (LCOE) of $0.052. They also found that its net present value (NPV) and payback time are $196,894 and 8.4 years, respectively. “Putting in place PV power plants next to the railway track might, all things considered, be a game-changing solution for Bangladesh’s rural areas, supplying reliable, affordable, and clean power to boost employment prospects, raise living standards, and lessen the effects of climate change,” they concluded.

Their findings can be found in the study “Techno-economic study of a photovoltaic power plant besides the railway track for rural uses in Bangladesh,” published in e-Prime – Advances in Electrical Engineering, Electronics and Energy. The research group comprises academics from the University of Dhaka in Bangladesh and the Bangladesh Council of Scientific and Industrial Research (BCSIR), as well as from the RMIT University in Australia and the Commonwealth Scientific and Industrial Research Organisation (CSIRO).