Off the coast of Singapore, an island is becoming a full-scale laboratory for the deployment of an autonomous energy network, a multi-energy microgrid – and hydrogen is a key element.
When it comes to electricity we are not all in the same boat. According to the International Energy Agency, 1.2 billion human beings, in other words 17 % of the world’s population, mainly in Asia and sub-Saharan Africa, do not have access to electricity! Of course we must remedy this situation, but without neglecting the climatic and environmental issues that impose, at an international level, the transition towards the massive use of renewable energies. This new vision of the energy mix, which by nature often integrates intermittent sources, invites us to reconsider our plans and to shift towards an increasingly decentralized distribution system. In this respect, drawing on local resources to limit the transport of fossil fuels is a key aspect for remote sites.
1 : The linchpin of the SPORE microgrid is Semakau Island’s wind turbine. © ENGIE
Within this framework microgrids provide the best solution. These small, independent networks collect and distribute decentralized, locally produced energy. They are particularly well suited to meeting electrification needs in South-East Asia, where there is a high degree of insularity and an infrastructure that is sometimes limited. Indeed it is often impossible to connect islands to the national grid. WELCOME TO SEMAKAU In these so-called off-grid regions, i.e. not connected to the national grid, microgrids provide a reliable and sustainable solution. What is at stake is managing energy supply (electricity, wind and solar power and biogas etc), connectivity and grid stability, whilst taking into account the characteristics of the various constituent parts of the microgrid, e.g. storage and production units, user demand and questions of mobility. A solution of this type is being installed on Semakau Island, which lies eight kilometers off the coast of Singapore. Covering a land area of two square kilometers (21.53 million square feet), Semakau is currently used as a landfill site for ashes from Singapore’s waste incineration plant. Part of the area has been allocated to Nanyang Technological University’s Energy Research Institute (ERIAN) so that it can pilot the REIDS initiative (Renewable Energy Integration Demonstrator - Singapore), a major project dedicated to the development of the world’s largest microgrid demonstrator in the tropics. REIDS is backed by Singapore EDB (Economic Development Board) and the NEA (National Environment Agency), two of the country’s most influential governmental entities. ENGIE Lab Singapore, ENGIE’s local expertise center, is developing an innovative microgrid - SPORE (Sustainable Powering of Off-Grid Regions) - on the island in partnership with Schneider Electric. So what is the current state of play in terms of the installation? In addition to solar panels and an Ineo battery, a crucial milestone was reached with the erection of the Xant wind turbine in October 2017, the highest in Singapore, which was especially designed for an off-grid configuration. Another major event was the delivery of a McPhy hydrogen refueling station and a Symbio FCell hydrogen car. The latter is part of a complete, so-called power-to-power hydrogen chain, which will be implemented on the island in the future and entirely connected to the microgrid
2 : If Semakau Island is energy self-sufficient, it is thanks to a complete hydrogen chain (connected to the microgrid) that goes from production and storage to its use as either electricity or fuel.
SPORE’s key element is a ‘hydrogen brick’ designed to store surplus energy in gaseous form and match energy generation to demand, thereby increasing the grid’s flexibility
Here hydrogen is used as a complement to batteries, which are the ‘conventional’ solution for storing electricity. The microgrid’s Ineo battery is a 200 kW / 200 kWh energy storage system. Whereas batteries are more suitable for short-term storage (in our case the average daily electrical consumption of 5 to 10 households), hydrogen is more advantageous in the long term, particularly to mitigate the impact of seasonal changes. Moreover with hydrogen, and depending on its use, storage capacity is easier to modulate because it is only limited by the size of the tanks. SPORE has a storage capacity of 2 megawatt-hours for 80 kilograms of hydrogen.
The microgrid also integrates the hydrogen production required by a vehicle Hydrogen Refueling Station (HRS). Hydrogen provides a green fuel that is directly produced and consumed on site and is, as such, a major asset in allowing remote regions to be energy selfsufficient. On Semakau, the station can refill up to 20 vehicles per day in just 5 minutes per vehicle and for a range of 200 kilometers, in addition to their existing autonomy.
3 : Semakau Island’s first hydrogenpowered car and the green hydrogen refueling station.
As illustrated by SPORE, hydrogen is very versatile. It can be used to store electricity in combination with batteries and is particularly well suited to renewable sources that are characterized by frequent surpluses of production and an inherent intermittence. It can also be use as a ‘green’ fuel for mobility solutions.
The complete power-to-power chain contributes to ensuring grid stability, while integrating the classical microgrid pattern. Its association with the other parts of the microgrid is optimized by management tools such as the Power Management System (PMS) designed by Schneider Electric and ENGIE’s multi-fluid and multi-energy Energy Management System (EMS).
The PMS ensures the stability of the grid in a real-time basis by balancing production, storage and consumption and takes up the challenge of maximizing renewable penetration in line with short-term demand. The EMS is dedicated to optimizing the microgrid in the medium term and its algorithm integrates weather forecasts in order to model intermittent renewable energy production with regard to changing weather conditions. Its software also models consumer demand using historical data. It also manages the grid’s fluids, such as biogas and hydrogen, which play a key role both for the microgrid itself and mobility applications.
This is a totally innovative approach. The technologies used to optimize a small-scale grid take up the challenges faced in developing microgrids, particularly in remote areas. Our desire to incorporate the highest proportion possible of renewable energies significantly affects grid stability and the SPORE demonstrator is an essential tool for validating the integration and optimization of different technologies, from their installation to their operation. As soon as it is commissioned, the microgrid will become a full-scale laboratory for testing and setting up new, innovative, smart grid solutions. SPORE will then be a replicable technological model for ENGIE with a view to the deployment of further microgrids, something that will change for the better the future of many territories and not just islands.