While renewable energy expansion is a key component of the energy transition, integrating these resources into power systems presents new operational challenges for transmission system operators (TSOs). Unlike conventional power generation, solar and wind output is variable and weather-dependent, causing fluctuations in electricity supply. Periods of high renewable output can create excess generation, while sudden drops can lead to sharp increases in residual load – the electricity demand that must be met by other resources. As a result, power systems require greater flexibility, which allows generation, storage and demand-side resources to quickly adjust their output to maintain the balance between electricity supply and demand. Ensuring flexibility has become a critical priority for TSOs seeking to maintain grid reliability and stability in increasingly renewable-based power systems.

The Mediterranean Transmission System Operators (Med-TSO) published a report, “Assessing Resilience of Power System – Flexibility Needs Assessment for Selected Southern and Eastern Mediterranean Countries TSOs”, to assess flexibility requirements in non-European Union (EU) countries: Morocco, Tunisia, Libya, Egypt, Jordan and Lebanon. Co-funded by the EU, the study reveals that solar and wind capacity in these countries is expected to triple between 2025 and 2030, with wind capacity projected to increase from 6 GW to 22 GW and solar capacity expected to grow from 8 GW to 23 GW. The analysis of flexibility requirements in the selected countries indicates that their power systems will face acute flexibility crisis unless TSOs rapidly advance storage, interconnection and cross-border coordination.

Comparing renewable penetration and grid impact

The report examines installed renewable capacity, electricity demand patterns, residual load behaviour, minimum load reduction driven by variable renewable energy resources (vRES) and extreme renewable penetration levels. Minimum load levels help identify the risk of overgeneration and the need for system flexibility during high renewable output and low demand, while extreme renewable penetration indicates high-stress periods. From Libya’s near-zero renewable penetration to Jordan’s solar saturation, the 2025 baseline indicates that the region is in transition, but at an uneven speed. Mid-term projections show that Egypt’s wind will more than quadruple by 2030 while Morocco will approach 90 per cent extreme penetration and Tunisia will generate more power than it can consume at certain hours.

Egypt

Egypt, which has the largest electricity system among the countries examined in the report, is projected to witness an increase in annual demand from 255.95 TWh in 2025 to 292.66 TWh by 2030. Over the same period, renewable energy capacity will expand, with wind capacity quadrupling from 3.04 GW in 2025 to 13.24 GW in 2030, while solar PV capacity will more than double from 3.13 GW to 8.04 GW. In 2025, renewables reduced demand by only about 8 per cent during low-load periods, while peak vRES penetration reached only 17 per cent, indicating that conventional generation continued to supply most of the electricity and the impact of wind and solar on Egypt’s power system remained limited due to its large electricity demand base. That said, by 2030, the minimum load reduction induced by renewables will rise to 38 per cent while extreme vRES penetration is expected to reach 54 per cent.

Jordan

Jordan has among the region’s most renewable-intensive power systems, despite having an electricity demand only one-tenth that of Egypt. In 2025, solar PV reduced the minimum load by 64 per cent and increased extreme vRES penetration to 79 per cent. This trend is expected to continue, with solar PV capacity increasing from 2.2 GW in 2025 to 3.62 GW in 2030. Meanwhile, minimum load reduction will reach 75 per cent and extreme vRES penetration 88 per cent by 2030.

Lebanon

Lebanon’s renewable energy mix is dominated by solar PV, with capacity projected to increase from 1.3 GW in 2025 to 2.13 GW by 2030, alongside the addition of 0.23 GW of wind capacity. Annual electricity demand will rise from 23.73 TWh in 2025 to 27.3 TWh in 2030. While extreme vRES penetration will increase from 33 per cent to 50 per cent during the same period, its impact on minimum load reduction will remain relatively modest, rising from 3 per cent to 20 per cent.

Libya

Libya remained heavily dependent on fossil-fuel-based generation in 2025, with only 0.05 GW of solar PV capacity. With annual demand at 43.8 TWh, renewable generation had no impact on system operations, showing no minimum load reduction and only 0.9 per cent extreme vRES penetration. Libya was excluded from mid-term data collection under the study due to limited engagement.

Morocco

Morocco demonstrated one of the region’s most diversified and renewable-integrated systems, with renewable capacity expected to increase from 2.41 GW of wind, 0.62 GW of solar PV and 0.54 GW of concentrated solar power in 2025 to 5.87 GW, 5.07 GW and 0.54 GW respectively by 2030. Annual electricity demand will increase from 47.66 TWh to 70.43 TWh. Minimum load reduction will increase from 35 per cent to 69 per cent and extreme vRES penetration from 47 per cent to 89 per cent, reinforcing Morocco’s position as a leading renewable power in the Mediterranean.

Tunisia

Tunisia will experience one of the most rapid renewable transitions among the assessed countries. Wind and solar PV capacity will rise from 0.23 GW and 0.44 GW in 2025 to 1.64 GW and 3.29 GW by 2030, respectively, while demand will increase from 22.41 TWh to 27.3 TWh. Renewable integration will strengthen considerably, with minimum load reduction increasing from 8 per cent in 2025 to 51 per cent in 2027 to 120 per cent by 2030, indicating periods of negative residual load where generation exceeds demand. Extreme vRES penetration will rise to 127 per cent, highlighting that surplus generation will need to be exported (through cross-border interconnections), stored or curtailed.

Ramping and flexibility needs

As solar penetration increases, grid operators must frequently ramp generation up and down by several gigawatts within hours, a challenge that grows with each addition of renewable capacity. The report highlights rising ramping requirements – the rate at which despatchable generation must adjust to accommodate changes in residual load – measured over one-hour, two-hour and four-hour periods. Even in 2025, the system experienced one-hour ramps above 3.1 GW per hour and four-hour ramps above 9.9 GW per hour for 5 per cent of operating hours. By 2030, ramping requirements will increase across all countries.

Egypt’s average four-hour ramp is projected to increase from 2.6 GW to 2.9 GW, with 95th percentile values reaching up to 6.1 GW, while Morocco’s average four-hour ramp will increase from 651 MW per hour to 1,162 MW per hour, with the 95th percentile reaching 2.7 MW per hour, and Tunisia’s average four-hour ramp will rise from 303 MW per hour to 764 MW per hour, with the 95th percentile reaching 2 GW per hour. The steepest ramps occur during winter, when lower demand and reduced solar output create stronger evening peaks and greater variability in residual load.

Further, the data shows a consistent increase in flexibility requirements across Egypt, Jordan, Lebanon, Morocco and Tunisia, reflecting the growing need for system adaptability due to higher renewable energy integration. Egypt records the highest flexibility requirements, with daily averages rising from 9.24 TWh in 2025 to 11.69 TWh in 2030. Other countries show moderate but steady growth. The annual flexibility needs are projected to increase from 23.54 GWh in 2025 to 29.87 GWh in 2030 across all countries.

Role of interconnectors in grid flexibility

A key finding of the study is that a fully integrated Mediterranean power system could significantly reduce flexibility needs compared to isolated national grids. The analysis compares an “isolated” case, where each country balances its own system, with an interconnected “copper plate” scenario where residual loads are pooled across countries. In 2025, the integrated system reduced daily energy flexibility requirements by about 8 per cent. By 2030, these savings are projected to increase to around 16 per cent. The benefits are even greater for peak requirements. By 2030, peak daily flexibility requirements will fall by about 25 per cent, while maximum weekly demand will decline by 32 per cent in the integrated case. Overall, the results show that as renewable penetration increases, cross-border interconnection delivers growing system value by reducing peak and ramping stress across the region. An interconnected power system significantly reduces the overall flexibility requirement compared to isolated national grids. In the “aggregated” scenario (which simulates unrestricted cross-border sharing), system flexibility requirements are consistently lower than the “total” or sum of individual national requirements. This is because interconnections help smooth out variability in wind and solar generation by sharing surplus and deficits across borders.

Interconnection also helps manage overgeneration and negative residual load. For example, Tunisia is projected to reach a negative residual load of 0.41 GW and extreme vRES penetration of 127 per cent by 2030, indicating that renewable generation exceeds domestic demand during certain low-load hours. In such cases, surplus electricity can be exported instead of curtailed. This highlights the significance of stronger cross-border coordination among Med-TSOs to maximise operational efficiency. At the same time, the growing share of renewables increases the need for energy storage, which helps absorb excess generation during low-demand periods and supports grid balancing when solar and wind generation exceeds demand.

Conclusion

The transition towards higher shares of renewable energy across the assessed Mediterranean countries is expected to significantly increase system flexibility requirements between 2025 and 2030. As renewable deployment accelerates, ramping requirements and periods of negative residual load are expected to intensify, with Tunisia facing the most frequent occurrences, particularly in winter when demand is low and renewable output remains high.  While solar and wind follow relatively predictable daily patterns, electricity demand varies seasonally, with summer demand creating mismatches between supply and consumption. This increases the need for flexible resources such as energy storage, thermal and hydropower plants, demand response and cross-border interconnectors to balance the system.