## 1 Introduction
[19] studied the thermo-economic design evaluation and optimization of the Central Receiver Concentrated Solar Plants, allowing for improvement of the thermodynamic and economic efficiency of the systems, as well as decreasing the exergy and exergy-economic cost of their products. [PERSON] et al. [20] made a review of considerations on the assessments for concentrating solar power potential of Algeria. The analysis showed the competitive viability of CSP plants. Algeria has the key prerequisites to make economical CSP power generation, including high-quality insolation and appropriate land, in addition to water availability and extensive transmission and power grid. [PERSON] et al. performed a technic economic assessment of a solar tower power pilot plant located in Tipaza, near Algiers. Using the economical, technical, meteorological, and radiometric data, they have carried a simulation of the solar tower power plants (STPP). The results showed that for a net annual energy of about 1 MW, the leveled cost of electricity is about 0.1/kWh, which is relatively high in comparison with the leveled cost of fossil power plant (0.04/kWh) [21]. [PERSON] et al. [22] showed that solar chimney power plants can produce from 140 to 200 kW of electricity on a site like Adrar (Algeria) during the year, according to an estimate made on the monthly average of sunning. This production is sufficient for the needs of the isolated areas. [PERSON] et al. studied two virtual sites in Algeria and in Spain; they showed a long-term reduction of electricity generating costs to figures between 4 and 6 ct/kWh in 2050. Although the greenhouse gas emissions of current CSP systems showed a good performance (31 g CO\({}_{2}\)-equivalents/kWh) compared with fossil-fired systems (130-900 CO\({}_{2}\)-eq/kWh), they could further be reduced to 18 g CO\({}_{2}\)-eq/kWh in 2050 [23]. [PERSON] et al. performed a techno-economic assessment of 100 MW of three types of concentrating solar thermal power plants for electricity generation located in one typical site of the Saharan environment of Algeria (Tamanrasset) [24]. The exploitation of Algeria's solar potential complements rural electrification programs. Currently, the use of renewable energies can reach regions far from the national electricity grid. The parameters and performance of the solar tower power plants of molten salt external receivers to be installed in the North of Algeria are currently not defined. The savings potential is very high and it is planned to install several plants, without the location yet being defined. Most of the studies focus on the south of Algeria, whose solar radiation is higher than the north. The aim of this paper is to analyze direct normal irradiation on the performance of solar tower power plants of molten salt external receivers in the North of Algeria to optimize the configuration of concentrating solar power (CSP). A comparison study between the three power stations located in the Algerian regions of Bechar, El Oued, and Djelfa, was presented. Each plant is equipped with a molten salt storage mode, the receiver is of external type and the implantation of the field of heliostats that has been defined for an annual production of 20 MW. This research is useful for prioritizing, sizing, and locating new installations and for determining the technical parameters to be used in the construction projects of solar tower power plants of molten salt external receivers. It will also be useful to define the ideal location based on the solar radiation that maximizes the yield of the CSP plant.