The installed solar capacity in Morocco remains relatively limited, representing around 8% of total installed capacity in 2024, with a total capacity of approximately 928 MW (PV and CSP combined). This should not be confused with the share of solar generation in the national electricity mix, which is only about 4%.
This situation may seem paradoxical given the country’s natural potential, located in one of the most sun-rich regions in the world.
Morocco’s solar potential must first be understood through the very nature of solar radiation and its components.
Concentrated Solar Power (CSP) relies exclusively on direct solar radiation (beam irradiance), which is concentrated to generate electricity. However, this component is strongly influenced by the atmosphere. Clouds, aerosols, water vapor, and other particles scatter and absorb sunlight, thereby reducing its intensity. The more the rays pass through a thick atmospheric layer (in the morning, evening, or winter), the stronger these effects become. This makes CSP particularly sensitive to weather conditions and therefore limited to very specific clear-sky locations. These constraints explain why CSP is mainly suited to arid and subtropical regions located under the descending branch of the Hadley cell. These areas include parts of Morocco, the Middle East, the southwestern United States, and Australia. They offer favorable conditions in terms of low humidity and high direct irradiation. However, even in these regions, atmospheric variability and the distance from consumption centers make large-scale CSP deployment costly, especially due to the required transmission infrastructure.
Photovoltaics (PV), on the other hand, exploit both direct and diffuse radiation (global irradiance), making them much more flexible and less sensitive to atmospheric conditions. Unlike CSP, PV production never drops to zero under cloudy conditions, as diffuse light continues to feed the panels. This reduces variability and allows installation across a wide range of geographical contexts. PV can thus be deployed both in large centralized plants and in decentralized systems.
A first major pathway to increasing Morocco’s solar capacity is therefore the rapid expansion of photovoltaics, particularly in decentralized form. Distributed solar, installed on the roofs of homes, public buildings, industries, and agricultural infrastructure, allows electricity to be produced closer to consumption. This reduces transmission losses, decreases pressure on the central grid, and accelerates the diffusion of solar generation without requiring large centralized infrastructure.
A second pathway relies on optimizing the technological mix between PV and CSP, with and without battery or thermal storage, taking into account their production profiles and correlation.
In a system dominated by photovoltaic (PV) and concentrated solar power (CSP), results show that PV generally remains dominant, while CSP is integrated only in small amounts. This is explained by the fact that both technologies are highly correlated: they both depend on solar irradiation and exhibit similar production profiles, particularly concentrated around midday. Thus, adding more intermittent solar capacity increases overall system variability, making it more difficult to reduce grid adequacy risks. CSP can provide a seasonal complement, particularly in summer when it performs better, but PV remains dominant due to its ability to exploit diffuse light and its lower variability.
When thermal storage is introduced in CSP (CSP-TES), the situation changes more significantly. Storage allows part of solar production to be shifted to hours of high demand when the sun is absent, particularly in the evening. This reduces daily and seasonal fluctuations and enables higher solar penetration in the electricity system. In this case, CSP with storage becomes more competitive, as it can smooth its output and meet demand beyond sunlight hours.
When the size of solar installations is increased, whether through CSP or PV, it does not only change the quantity of electricity produced but also the way this production is distributed over time. In CSP, increasing the SM parameter (which corresponds to the size of the solar field and associated thermal storage capacity) allows more solar energy to be captured and, more importantly, distributed over a longer period of the day. Similarly, for PV, increasing the ILR (which reflects the sizing of the solar field relative to the conversion and storage system) increases production and allows it to be better spread over time when coupled with batteries.
Concretely, this means that the higher these parameters are, the more regular solar production becomes and the less it is concentrated solely around midday. A CSP plant with a low SM (for example SM2) can only produce during hours of direct sunlight, with possibly a slight extension into the evening. In contrast, with a higher SM (SM3 or SM4), the plant can store a significant amount of thermal energy during the day and continue producing after sunset. The same reasoning applies to PV: with a low ILR, production strictly follows the sun, whereas with a high ILR and storage (BES), it can be shifted and used later in the day.
This ability to “shift” production is essential, as it reduces the variability of solar generation. In other words, the more systems are sized with storage or solar field oversizing, the more stable and predictable production becomes. It also increases the number of full-load equivalent hours, which is an important indicator of profitability and efficiency. Without storage or with low sizing, plants only produce when the sun is available, which limits their effective utilization during the day.
Another important result is that there is often a form of substitution between CSP-TES and PV-BES. In other words, in a given system, when the capacity of one technology is significantly increased, the other tends to disappear from the optimal mix. This is because both technologies fulfill a similar role when coupled with storage: they both shift production over time and smooth solar variability. The system therefore does not always need both simultaneously to achieve a good level of flexibility. This substitution leads to less diversified energy mixes than one might intuitively expect. Instead of strongly combining PV and CSP, the system often “chooses” a dominant technology depending on storage and sizing parameters. This reduces overall system variability, as a single optimized technology can manage much of solar intermittency.
Finally, when comparing different storage levels, it appears that the dominant technology strongly depends on available storage duration. With low storage capacities, one technology may dominate the mix, but as storage increases, another may become more efficient. For example, PV with a strong battery system can outperform CSP with low storage, but CSP with high storage can become more competitive than certain PV configurations.
In summary, the central idea is that the sizing of solar technologies (SM and ILR) does not only change the amount of energy produced, but fundamentally transforms the temporal structure of production, system variability, and even the optimal choice between competing technologies.
However, as solar penetration increases, a structural phenomenon emerges. In a traditional electricity system without a strong share of solar, demand generally follows a relatively balanced curve, with two moderate peaks (morning and evening), resembling the shape of a camel. The grid is then mainly supplied by dispatchable plants (often thermal), which can follow demand relatively steadily.
But as photovoltaic production increases, this structure changes profoundly. Solar power is mainly produced around midday, when irradiation is highest. This massive production directly replaces output from conventional plants and significantly reduces the amount of electricity the grid needs at that time. A sharp drop in net grid demand is then observed around midday: this is the “belly” of the duck. This situation can even lead to oversupply, where available electricity exceeds demand, sometimes forcing curtailment of solar production to maintain system balance. During this phase, electricity prices tend to fall sharply due to excess supply.
However, this situation reverses abruptly in the late afternoon and evening. When the sun sets, solar production drops rapidly, while demand increases significantly (lighting, cooking, cooling, evening economic activity). This transition creates a steep rise in residual demand that the grid must cover. This is the “head” of the duck: a sudden peak in net consumption. At this critical moment, the system must rely on alternative energy sources, often thermal or peaking plants, which are more expensive to ramp up quickly. This leads to higher electricity prices.
This dual phenomenon—excess production at midday and shortage in the evening—creates a structural imbalance in the electricity system: oversupply during the day (curtailment) and undersupply in the evening (shortage).
This problem becomes even more complex when the electricity system relies on inflexible thermal plants. These units cannot easily reduce their output at midday to accommodate excess solar due to minimum technical operating constraints. They are therefore sometimes partially or fully shut down during the day, reducing their availability. But they cannot always restart quickly in the evening to meet peak demand. The system is thus caught between two constraints: absorbing solar excess during the day and ensuring sufficient flexible capacity in the evening.
Thus, the transition to a highly solar-based system is not only a question of energy quantity, but above all a question of temporal flexibility in the electricity system. The main challenge is no longer simply producing electricity, but producing it at the right time.
In conclusion, the case of Morocco highlights a structural paradox: a country endowed with some of the world’s most abundant solar resources, yet whose installed capacity and solar penetration remain relatively modest. The analysis shows that solar exploitation does not depend solely on the abundance of sunshine, but primarily on the ability to manage its temporal variability. The development of PV, CSP, and storage solutions reveals that the main challenge is not only to add capacity, but to integrate it coherently into a system capable of absorbing daily and seasonal fluctuations in production. Having the resource is not enough. Without adequate infrastructure, grid flexibility, and coherent technological choices, an exceptional energy potential can remain partially underexploited.