Chiara Di Silvestro (Italy) 1
1 - Tractebel - ENGIE
Long-term changes in the climate behavior and short-term increases in climate variables are impacting more and more on the generation of electricity.
In the Mediterranean region, Tunisia is facing a growing energy demand. At the same time, the increase in the air/water temperatures induced by climate change is impacting on the performance of conventional power generation plants. As a consequence, the power sector is highly vulnerable in the absence of effective mitigation and adaptation investments.
The study we developed for the European Bank for Reconstruction and Development (EBRD) has demonstrated that at least these climate trends are relevant to the Tunisian energy sector:
- Air and water temperatures: Higher ambient air and water temperatures affects the performances of all fossil-fuelled power plants.
- Water availability: Water scarcity induced by climate change is also a constraint as water is often used to cool the equipment down or to produce steam.
- Flooding and sea level rise: These two hazards can affect plants downtime and potentially cause damage to plant infrastructure.
To identify suitable investments improving the area’s climate resilience, a case study has been performed on Sousse-B cogeneration plant, South-East of Tunisia.
Sousse B is a 360 MW plant, composed of two gas turbines and one steam turbine. Being installed on the seashore, the plant uses seawater to cool down the equipment.
The identified solutions allow the plant mitigating the climate change effect foreseen in 2030 and 2050 forecasts: a loss of capacity and a reduction of performance. A short description of the solutions is reported here below:
- Cooling the gas turbines inlet air
- Enhancing the turbine’s power output by a technological upgrade
- Optimizing the air filtration system
- Installing an automatic cleaning system for the air compressors
- Reducing water losses in the cooling circuit and in the steam cycle
The implementation of the above mentioned solutions will contemporarily:
- Increase the plant’s power output (+ 20 MW)
- Improve the current performances (+ 5 %)
- Decrease the fuel and water consumption (- 40,000 m3/y)
- Decrease maintenance costs
The method developed to identify mitigation opportunities have been applied on two other plants in Tunisia and it could be replicated on other power generation plants in order to help fighting climate change’s effects.