Mideast Power Grids: How To Integrate Renewables & Maintain Stability – EQ Mag Pro

The energy transition is underway in the Middle East with net-zero targets set and an acceleration of renewable power investment. The shift to renewables brings challenges for grid stability. Siemens Energy’s Elyes San-Haji* lays out how these can be tackled.

The current energy crisis is making one thing clear, we need to transition away from fossil fuels as soon as possible. A shift to renewables can offer a myriad of benefits, not just greener electricity, but more stability in prices, security of supply, and the potential to reduce geopolitical insecurity through a greater distribution of resources.

The good news is that the technology is already available, the political will is there, and the social demand is there. The shift has already started in the Middle East where installed renewable energy capacity rose 4.5% to reach 24,049 MW in 2021 according to international renewables agency Irena the largest current component is from hydropower plants in Iran and the regional total is set to soar in the coming years as major regional investments in solar and wind come online.

In just eight years, from 2008 until 2016, investments in renewables across the region increased nine-fold to $11bn from $1.2bn in 2008. The pace will only accelerate from there. Today, several countries in the region are among global frontrunners in renewable energy development.

THE CHALLENGE OF INTERMITTENT SUPPLY

The challenge going forward will be to manage the strong fluctuations that result from intermittent renewable energies. Power from wind and solar complicates management of the grid because they are variable – they vary with the weather conditions. You can’t ramp them up and down as we do with fossil fuel plants. This vastly increases the complexity of matching supply to demand in real time, and creates an urgent need for flexibility.

The transmission network is the lifeline that connects everything, so addressing this challenge is one of the most important components of a successful energy transition. Today’s grids are not prepared for this challenge which affects network voltage, frequency and load flow. We need grid stabilization and storage in order to prepare our grids for the future and that means more investments in grid infrastructure.

This was a topic of debate at the MEA Energy Week conference in June, and the conclusion was that if we want a successful energy transition and we want to build out renewables, it doesn’t come for free. We need to invest in and build out transmission grids. If we want a net zero future, it will cost us, but it is an investment in the future for the planet and future generations.

In order to do that, utilities must invest in a holistic program. They will need proper storage technology coupled with Grid Control and Grid Stabilizers (SVC).

The solutions needed to make the grid more resilient will help with fast-reacting voltage control under various load conditions, providing inertia and fast frequency response in case of sudden changes in generation or load and enabling dynamic load flow management to make the best use of the existing grids and renewable generation.

TECHNOLOGICAL SOLUTIONS

Besides maintaining grid fundamentals such as stabilized voltage, strong frequency, and balanced power flow, it is also essential to ensure full and quick control under all circumstances. While we are practiced and proficient at exerting control under a steady state, it is challenging to do the same under fast changing conditions, so it was essential to introduce power electronics into high voltage transmission systems.

One of the most important power electronics solutions on the market is the High Voltage Direct Current (HVDC) system. This system can connect renewable energy bulk power sources with load centers as well as establish interconnected grids between countries. This makes them essential for the grids of the future.

One of Europe’s most important energy projects, the 190km Greenlink Interconnector which will link the power grids of Ireland and Great Britain, will rely on the HVDC system. This project will allow both countries to benefit from increased grid stability, security of power supply and cost-effective growth and integration of low carbon renewable energy.

But the challenge we face is not limited to connecting renewable energy to the grid. We must also improve grid transmission quality and efficiency. Due to the intermittency and volatile nature of renewable energies, grid stabilization technologies will play an increasingly important role for a successful energy transition. We must look at supplying reactive power to the grid and ensuring stable grid voltage to avoid dangerous voltage drops.

This will require investments in flexible alternating current transmission systems (FACTS). Such systems increase the power transfer capability of transmission lines and help to make grids more reliable by increasing voltage stability and regulation.

With the removal of rotating equipment – like gas and steam turbines – from the grids of the future, we will also need to address the missing inertia. The energy stored in rotating generators enables them to remain rotating, reducing large voltage fluctuation in grids. Grid inertia is the factor that protects our grids from sudden blackouts so it must be substituted to ensure grid stability.

One solution that could provide a substitute for missing inertia, whilst providing reactive and short-circuit power, is the so-called synchronous condenser which is basically a large rotating generator connected to the high-voltage transmission network via a step-up transformer.

These solutions will need to become more widespread as countries’ energy mixes are increasingly weighted towards renewables. For example, renewable energy made up 53% of total Estonian power output for Q2 2020. We are already providing three 330 kilovolt synchronous condenser plants at Püssi, Viru and Kiisa in the north of Estonia. These will ensure stable operation of the Estonian grid while also providing or absorbing reactive power. Such projects will help with the smooth integration of renewables to our grids.

Digital technologies will also have a big role in the grids of the future. Smart grids will become a key enabler to the new world of renewable systems. It is important to use state-of-the-art digitalization technologies to safely manage the new grid ecosystem and leverage all automation potential. Data analytics and state predictions will boost the utilization of transmission assets tremendously by enabling better transparency, availability and operational efficiency.

To deliver electricity in the required quantity, quality, and reliability, grids must be prepared with the right set of capabilities. Expanding, automating, and upgrading the transmission grids as well as ensuring grid stability are fundamental prerequisites for the success of the energy transition.

Source: mees