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Renewable energy for TLC

Simea Traditional raw land sites not grid connected

Simea (Alternative Energy Modular Integrated System) represents an alternative solution to the use of the diesel generators for all those sites not connected to the national grid; it is composed of photovoltaic and wind generators, a set of batteries as well as an energy management and telecontrol system. Furthermore, a fuel cell can be added to the system as a backup generator in order to increase autonomy.

The power supply of the radio base stations has often been granted by diesel generators causing an increase of the operating costs. The substitution of the diesel generators with alternative generators (wind, photovoltaic) is complicated by the irregular energy supply as well as the need of the accumulation system. The traditional accumulation systems, using lead batteries, even if working in almost all climatic conditions, is limited by several issues (deep discharge, sulfatation, loss of efficiency at high temperatures), the installation and maintenance costs can furthermore be very high. calzavara proposes to replace the diesel generators with a photovoltaic plant and an advanced energy storage system using an innovative technology granting a regular energy supply.

The main advantages of this innovative system compared to the lead batteries are:

  • Very low Self discharge (less than 1% per year)
  • Complete discharge (0-100%) without memory effect
  • Charge / discharge efficiency: 80%
  • Lifespan 15 year
  • Reduced maintenance costs (only 2 high efficiency circulation pumps)
  • Stable at high temperatures
  • Voltage: 48V DC or 230V ACTensione: 48V DC oppure 230V AC

Operating scheme


The energy storage system stores electrical energy under the form of chemical energy thanks to the reagents contained in the external reservoirs. The system has no moving parts except two circulation pumps, that are actived during the loading and unloading periods to supply reagent to the electrodes. The storage capacity of the electrolytic solution depends on the reservoir's dimensions, the efficiency can go up to 80%.

Sample application to a radio base station

Supply of a radio base station absorbing 2 kW continuously 2 kW complete with air conditioning system of 10 kW.

  • Voltage: 48V DC
  • Size of the energy storage system: 4,5 x 2,2 x 2,4 m
  • Storage capacity: 200 kWh
  • Power of the photovoltaic generator: 15kW
  • Payback period compared to a diesel generator: approx. 5 years (without considering an increase of the fuel costs), 4 years considering a fuel cost of 2,00 €/liter
Graph 1: cost of the photovoltaic system + accumulator.
Graph 2: battery state of charge. The system uses the complete capacity of the accumulator (state of charge comprised between 0 and 100%) maintaining an average operational reserve higher than 60% (approx. 3 three days of complete autonomy).

Photo Gallery


Catalogue 2010

Size: 17.53 MB