Processing industry in Portugal

Processing industry in Portugal

This micro hydro power (MHP) plant will be testing how energy recovery through pump as turbine technology can be optimised in existing water networks.  The MHP unit is based in the outflow of waste water from a paper processing plant, harvesting lost energy for reuse and lowering the energy demand of the factory.

This demonstration site is currently under construction, and is expected to be producing results in Spring 2020.


Renova SA is an important paper producer which exports globally to more than 170 countries.  The demonstration site is located at Renova's facilities in the centre of Portugal, near the city of Torres Nova.  Renova's paper processing factory in PortugalHere, two Renova facilities have several hydraulic circuits with many different purposes, one of which has been identified as suitable for the installation of a micro hydro.   The selected circuit transports effluent from a Water Treatment Station at the Renova facility to the Almonda River nearby.

The Technology:

The main characteristics of this hydraulic circuit are:

Upstream > Downstream

  • L1= 251 m (sub-horizontal; within the facility)
  • L2= 236 m (deep inclination; through natural terrain)
  • DN= 300; PVC
  • 0.016 < D < 0.050 m³/s
Daily flow m³/Day m³/h
Maximum 4262 178
Average 2860 119
Minimum 1378 57







Table 1: Daily flow data from 01/01/2017 to 29/10/2017

Maximising net present value is one of the most critical features in Micro Hydro Design: the hydraulic circuit optimization contributes to maximize profitability. Similarly, it is important to shorten longitudinal development and reduce head loss. After analysing the possibilities thoroughly, the previously design of hydraulic circuit has been reduced in about 50% of the length, with almost no head loss. 

The figure below presents an aerial picture of the facility with the new reduced development of the hydraulic circuit (54 %).  It has been necessary to install a forebay in order to guarantee a pressurized flow in the circuit downstream, until it reaches the power station section.

Characteristics of this circuit are:

Upstream > Downstream

  • Ddim = 0.030 m3/s;
  • h = 33 m;                      
  • L = 265 m;
  • P ~ 8 kW;
  • not in pressure;
  • enclosing pipes in visit boxes 

We are currently testing a new location to comply with APA requirements.  This should have the following advantages:

  • On the slope toe in order to avoid implanting on the flood bed of the river
  • Mantaining total Head
  • Lower head loss
  • Lower flood risk
  • Easier to obtain authorization
  • Better hydraulic conditions


Installation and management

The technology is being installed and monitored by REDAWN partners Hidropower, in collaboration with Renova.

Latest progress:

Autumn 2019: Installation of the MHP infrastructure has begun.  The demonstration plant will be presented to stakeholders soon, with a formal launch event featuring speakers from the REDAWN team. 

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Read more

View this presentation by Hidropower on the Portuguese Demonstration Site