Author : Aroune Ghadbane, Rome, Italy.
The working principle of concentrating solar panels (CSPs), relies on using parabolic-shaped mirrors that concentrate solar energy at a focal point and transform it into a useful form of energy such as heat and electricity.
Solar radiation is concentrated using parabolic mirrors or lenses at a point usually referred to as the fire point. A pipe transports fluid with heat storage such as molten salt, thermal oil, or pressurized gas from the receiver to a thermal storage tank (lasting only a few hours). The purpose of having a thermal storage tank is to guarantee the continuity of the production in case of small intermittency in solar radiation (Fogs for instance). When energy production is needed the fluid flows through a heat exchanger and transfers heat to water that becomes superheated steam and drives a high-efficiency steam turbine. After that, the steam condenses and goes back to the water tank while the fluid leaving the heat exchanger is pumped back to the receiver. There exist many forms such as solar towers, solar dishes, and parabolic troughs.
Operating principle of a solar tower
Example – Moroccan Kingdom Energy transition and Solar project
The kingdom of Morocco lacks conventional energy resources, and back in 2009, Morocco was 95 % dependent on export to meet its growing energy demand estimated by an average increase of 6.5% per year since 2000. This increasing electricity demand is inherent in the rapidly growing demography, industries, and economic expansion of the country. To overcome this dependency, the Moroccan kingdom implemented in 2009 a new national energy strategy to increase its electricity production coming from renewable energy sources, guarantee a steady and continuous supply of energy and increase the electrification of rural and remote areas at a reasonable cost. In order to achieve its goals, Morocco is working on diversifying its energy sources by developing a national renewable energy production system and focusing on energy efficiency. By 2030 Morocco is aiming to develop a mix of solar, hydro, and wind representing more than 52 %.
Noor solar complex is one of the projects developed to achieve these goals. It has a targeted capacity of about 580 MW. The name “Noor” comes from the Arabic pronunciation of the word light. The Noor-Ouarzazate solar complex has a targeted capacity of 580 MW distributed over three main phases: the first consists of 160 MW power coming from concentrated solar thermal technology with cylindrical parabolic mirrors. The second phase consists of 350 MW CSP technology distributed as follows: 200 MW from cylindrical parabolic mirrors and 150 MW from solar tower technology. The third phase is the construction of Photovoltaic systems with an output of 70 MW.
The total area allocated for this project was 1903 ha. This project did not only contribute to the country’s goal of reducing its dependence on external electricity supply but also reduced the greenhouse gas emissions of the electricity sector in morocco, created temporary job opportunities during the construction of the facility and permanent jobs for the operation and maintenance of the technologies used, adding to that it increased the integration of local industries in the renewable energy sector.
Morocco has become an eldorado of renewable energy as it shows a successful example of a fast and effective transition from fossil fuel dependency to renewable energy production. Dr. Leila Benali, minister of Energy transition and sustainable development, declared on 2/11/2021 at the Cop 26 that in addition to 50 renewable energy projects with an installed capacity of about 4 GW already operational, many other projects are being implemented and developed, also that Morocco is focusing on energy efficiency, strengthening regional and industrial integration, and that it aims to exceed the target of 52% energy mix before 2030. Dr. Leila also mentioned that the goal for the next decade is to simplify the governance of the sector, simplify the legal and institutional framework, open up to the private sector, improve innovation and industrial integration and, most importantly, achieve balanced international cooperation.
The country was ranked 5th worldwide in the climate change performance index 2022.. Below we can see a comparison of the energy mix of Morocco between 2009 and 2020 and , remarkably, there is a clear transition of clean energy sources.
(contact source for pictures)
Solar Engineering of Thermal Processes, John Duffie