Evaluation of the potential for hybridization of gas turbine power plants with renewable energy in South Africa

Abstract

Domestic energy supply to rural area is a task fa cing many governments. In efforts to meet this target, electricity generating companies have tried to exploit available resources of energy, including the combustion of fo ssil fuels even though they have been recognized to cause environmental problems such as climate change and acid rain. Moreover, these resources occur in limited quantities and therefore pose energy insecurity. It is believed that the addition of renewable energy (RE) resources in the general energy mix can assist in mitigating climate change and in augmenting energy security. This paper investigates the possible renewable energy that can be exploited in hybrid gas turbines (OTs) in South Africa (SA). In this study, data was collected through a desktop approach. It is fo und that there is potential for use of biodiesel, biogas, and concentrated solar power in OTs. Results also show that about 2.00 xlO 6 MWh, 12.09 x 10 6 MWh and 105.0 x I 0 6 MWh of electricity can be annually generated from biodiesel, biogas and concentrating solar collectors respectively through the gas turbine technology in SA. It is concluded that there is great potential for exploiting solar and biogas resources to drive gas turbine power plants in the country.

Thermodynamic model of a hybrid Brayton thermosolar plant

“…The term hybrid refers to the fact that during low solar radiation periods a combustion chamber ensures a stable power release to the electricity grid and avoids the use of storage systems [9]. Several hybridization strategies have been proposed [10]. Hybridization can be performed by retrofitting an existing standard fossil plant or designing an original hybrid one [11].…”

“…Usually there is more flexibility in designing and optimizing a brand new one, solving the design challenges properly. It is thus required to simulate the hybrid system, taking into account technological, thermodynamic, and economic ingredients [7,10,12]. For design purposes it is usual to choose particular stationary conditions for solar irradiance and ambient temperature.…”

Seasonal thermodynamic prediction of the performance of a hybrid solar gas-turbine power plant

“…Then, the two streams are mixed before the expansion in the turbine. This scheme has some practical advantages (operation and maintenance), but thermodynamically, the serial configuration is more profitable [18]. Hybridization can be performed by retrofitting an existing standard fossil plant of designing an original hybrid one [19].…”

“…Usually there is more flexibility in designing and optimizing a brand new one, solving the design challenges properly. It is thus required to simulate the hybrid system, taking into account techno-economic and thermo-economic ingredients [10,18,20].…”