Growing the share of renewables on the grid is an essential step in the path towards a carbon-free energy system. But as the share of renewables grows, so do issues with grid integration. Intermittent renewables not only pose challenges in matching supply to demand, but also replace spinning reserves that provide valuable ancillary services, such as frequency and voltage control, for the hybrid grid.
These challenges can be overcome, but they require the use of smart control systems that are able to integrate, track and manage the output from diverse electricity generation assets, including not only wind and solar plants but also energy storage and legacy thermal generators. To maintain a stable, reliable service, these control systems need to be able to operate on a second-by-second basis—and also scale to the cover the entire grid throughout the day. The Wärtsilä Renewables+ GEMS solution is one of the few in the world that can control and optimise renewables based portfolios like this.
Hybrid Performance
With the Wärtsilä Renewables+ GEMS solution, grid operators can:
- Minimise the levelised cost of energy by reducing fossil fuel consumption and maximising renewable generation.
- Improve grid quality by adding fast-responding battery assets to the electricity network.
- Predict energy generation using load and renewable energy generation forecasting.
- Enhance grid safety by optimising asset dispatch and maintaining reserve levels.
- Manage and optimise various assets under a single portfolio.
Zero Emissions
Wärtsilä’s Renewables+ GEMS solution is already helping the holiday destination of Bonaire became one of the first islands in the Caribbean to set a course for 100% renewable energy after a fire destroyed its diesel generation plant in 2004. As part of that goal, utility provider ContourGlobal Bonaire, in cooperation with the Caribbean island of Bonaire’s power company, Water en Energiebedrijf Bonaire NV, sought out an advanced energy storage system with Wärtsilä Energy.
The system uses Wärtsilä’s GEMS energy management platform to allow customers to tap into the full potential of renewable energy resources. It enables intelligent energy applications that increase resilience and efficiency and can be supported by the power producer’s existing grid infrastructure. The energy management platform is a linchpin for renewable commitments like Bonaire’s because it is able to synchronise all power assets within a hybrid system, while allowing new resources to be integrated easily.
Optimising Operations
GEMS controls most of the island’s power and eliminates renewable intermittency issues using artificial intelligence and historic and real-time data analytics to calibrate what type of generation is needed at a specific time. The first phase of the project involved GEMS managing and optimising the dispatch and operation of existing generation assets. It also provided spinning reserve requirement with energy storage to reduce fuel consumption and emissions.
The project helped unlock curtailed wind energy and improve system reliability by providing frequency and voltage control. To optimise the system, GEMS factors in real-time asset performance as well as load and renewable energy forecasts. After the first phase of the project with Wärtsilä, the island stopped curtailing excess wind energy, increasing annual output by up to 8% and preparing the system for additional capacity to accommodate peak demand during the tourist season.
CASE STUDY: FEKOLA MINE, MALI
Photo: Fekola Mine, Mali
Source: Wärtsilä & B2Gold
If renewables integration is already problematic for national grids, in microgrid or off-grid situations the situation is even more challenging. This is typically the case with remote mines, which require reliable electricity supplies for round-the-clock operations and frequently have to pay a lot for a grid connection or on-site fossil fuel.
Embracing renewables
Many mining companies are keen to embrace renewables—but in a way that does not compromise the security and quality of their electricity supply. In Mali, for example, Wärtsilä was contracted to deliver a hybrid solution at B2Gold’s off-grid Fekola Mine. Wärtsilä’s GEMS advanced energy management system is being used to integrate, control and optimise a 17.3 MW/15.4 MWh energy storage system alongside a 30 MW solar PV plant and the mine’s existing 64 MW power generator.
Hybrid project
The main application of the Fekola hybrid project is to provide and maintain microgrid stability. This means dispatching energy storage and renewable energy generation assets with the right reserve level to maintain high grid reliability for a mine in a remote area with no connection to any larger grid.
Control and optimisation
The control and optimisation capabilities provided by GEMS are key to handling large load step changes and the volatility of renewable power. Wärtsilä’s GEMS software uses artificial intelligence as well as automated and forecasted data to maximise efficiency and operate the system’s assets optimally.
Lowest cost
GEMS can dispatch or draw energy according to changing conditions and forecasts: for example, gensets are switched off as solar output increases, and later they can be restarted based on the forecast conditions. The result is a stable grid in the context of solar power fluctuations. Furthermore, the way GEMS optimises energy production optimisation ensures that the Fekola mine achieves the lowest possible levelised cost of electricity.
