Increasing Turkey's power system flexibility for grid integration of 50% renewable energy share

Secure and reliable operation of power systems with high wind and solar shares requires system flexibility. In this paper, an hourly-based market and grid simulation model is developed to assess security and reliability of a power system with high wind and solar energy share. The model is applied to Turkey as an emerging G20 country that aims to supply its rapidly growing electricity demand from local renewables and lignite as well as nuclear energy. The most ambitious scenario that covers the 2016–2026 period assumes half of all electricity demand is supplied from renewables (30% wind and solar and 20% other resources). This is achieved by ensuring system flexibility through system-friendly location of wind and solar capacity, energy storage, flexible thermal generators, and demand response. Without system flexibility, 3% of renewable power is curtailed and redispatch share required for system security and reliability doubles from current levels. Moreover, additional transmission grid investments are needed. Improving system flexibility ensures secure and reliable operation but increases system costs by 1%–5% with each flexibility option providing different scale benefits, indicating the need for system-wide planning. As gas-based generation declines below 10%, accounting for energy security benefits will be important. On the other hand, coal supply remains around 25% depending on nuclear energy development. At this crossroad, Turkey needs to make its choices to transition to a secure, clean and affordable energy system. The study addresses quantitatively how the flexibility options contribute to such a transition, providing learnings for countries with similar conditions. •Market and transmission grid of Turkey is modelled until 2026 on hourly basis.•Wind and solar can supply 21% of all electricity demand without operational issues.•30% share can be reached but redispatch, curtailment and grid investments increase.•Integration requires energy storage, flexible thermal generators and demand response.