By Bernhard Loher ABB Energy Industries.
How do we find solutions for sustainable, compliant, and agile power generation, where the power demand profile and power supply profile are matched for consistent grid stability and minimal energy wastage? Power grid operators are facing new challenges to meet ever surging demand with consistent and reliable power. Virtualization is set to become a key enabler in efficient supply and demand management and optimization – ensuring grid stability.
The evolving energy landscape
Traditionally, power generation was centralized with conventional large power plants, resulting in a constant and reliable power flow to millions of end-users. The predominately mechanical rotating mass systems created stability in the grid. Changes occurred relatively slowly, and frequency fluctuations and other issues could be easily controlled.
Today the shape of the grid is evolving rapidly. We are moving from a system of large traditional power plants to a decentralized system of smaller renewable energy power providers.
In this system managing demand and supply is much more difficult. Put simply, the sun doesn’t always shine and the wind doesn’t always blow, so you cannot ramp-up solar and wind power at will to meet demand. Renewables also do not provide inertia or mechanical rotating mass to the system.
Additionally, energy supply is facing huge fluctuations in demand as electricity needs evolve, with rapid electrification driven by electric vehicles, heating, cooling, data centres and emerging industries. This changing grid profile increases the likelihood of events such as fast rate of change of frequency (RoCoF), fault-ride through (FRT) and power oscillations. To ensure network stability under these circumstances transmission system operators (TSOs) have established new grid codes, the rules to which all players that connect power-generating assets to the grid must comply to react to such events.
The challenges lie in both how we integrate renewables into the grid but also how we react to unpredictable demand.
Overcoming grid challenges for today and the future
Virtualization helps to ensure grid stability in several ways. Firstly, it is essential to have a model, or digital twin, of the grid assets that reflect the physical reality as closely as possible. On one hand, the grid authorities require this digital model of systems so that they can perform simulations to ensure grid stability and to plan future investments to strengthen the network in its weak points. On the other hand, by simulating the equipment performance, power operators can demonstrate to TSOs that their equipment is compliant with the grid code requirements and that it can effectively counteract events that cause network instability. In countries with strict grid codes, including Germany, Australia, the US, South Africa and Singapore, this is more important than ever.
These simulation models are critical in this rapidly evolving network environment. For example, ABB Excitation systems damp voltage and power oscillations control the grid voltage to ensure that the supply of electricity to consumers remains constant. Performing network simulations with detailed digital twins adds an extra level of security. It enables the evaluation of how well the system damps the network oscillations and how fast it can provide voltage support during network faults, well before its connection to the power grid. With this proactive approach both TSOs and power producers can ensure maximum possible power transfer to consumers, even during network contingencies.
Another concept which relies on virtualization is a Virtual Power Plant (VPP). In essence this is one large virtual power plant created from the hundreds of smaller physical plants; pulling in the optimum load profile of each individual power plant to make sure that you supply to the grid in the most efficient and cost-effective way. This allows for demand profile matching. As grids become more decentralised and power generation and demand fluctuate more wildly, this virtual representation of physical assets becomes invaluable and empowers companies with high quality data and insights so that they can prepare for changes in grid behaviour, optimize processes and streamline operations, providing the dual benefit of creating a stable power supply alongside positively impacting the bottom line.
Case-study: Next Kraftwerke
VPPs from ABB are being used in several locations around the world, including in Next Kraftwerke in Germany, where they have the strictest grid code compliance requirements.
The solution enables Next Kraftwerke to pool the production of hundreds of small- and medium sized renewable energy plants into a VPP that has the scale and flexibility to participate in the country’s lucrative ancillary services market. The VPP collects plant production and grid balancing data, performs real-time optimization calculations, and determines the production schedules for each power plant to ensure that grid stability is maintained. If an imbalance occurs Next Kraftwerke receives a command from the TSO to increase or reduce output either immediately or within minutes of the command being issued. The command is received and acted on in real time by the ABB solution.
ABB based this solution on its ABB Ability OPTIMAX® plant optimization software, which is part of ABB’s Symphony Plus platform of total plant automation systems for the power generation, water and process industries.
Since the installation of OPTIMAX® in 2012, Next Kraftwerke has seen rapid growth and can comfortably meet its own power demand while providing energy services for the wider economy.
In this new energy landscape VPPs provide an invaluable tool in transforming the performance of the grid. They can aggregate production from multiple power generation plants and energy storage to achieve flexibility and scale. By matching the demand profile and reacting by smartly distributing power, a VPP has a powerful ability to create a stable grid today and for the future of energy supply.