Despite its potential, solar energy still remains an intermittent energy source, which fluctuates during heavy cloud cover, rainfall, and disappears at night. Power grids need a stable balance between electricity generation and load demand, an overload or under-supply of energy can threaten grid stability, deteriorate power quality and cause power outages.
Micro-grids can help to bridge this gap in grid stability and resilience. They could be independent island grids that supply power to off-takers from both renewable and conventional (e.g. diesel) energy sources. They can export power to the main grid when there is energy surplus. In times of main grid failure, they can also separate themselves from the main grid to maintain stable power supply.
Micro-grids can also power remote islands that were previously geographically impossible, or too expensive, to link with a main grid. This positions micro-grids as the ideal solution to power up countries that need stable utility-quality electricity to keep up with their fast-paced economic development.
WEnergy Global, a Singapore-based SME in the renewable energy sector, saw the opportunity of developing a micro-grid to power up the Sabang Underground River Area, a prominent tourist destination in the Philippines’ Palawan Island.
The area is isolated from the main grid in Palawan, which is fully powered by heavy-diesel generators. WEnergy Global is about to commence construction of a hybrid micro-grid worth approximately US$9 million . It has a capacity of 1.4 megawatt-peak (MWp) generated from solar PV power, a 1.2 MW diesel generators, as well as a battery storage system of 2.3 MWh .
In 2013, WEnergy Global partnered with ASTAR’s Experimental Power Grid Center (EPGC), which has strong expertise in micro-grid and intelligent power system design and development, to analyze and refine its micro-grid components and system design through simulations.
Unlike smaller lab setups or simulations, the 1-megawatt (MW) experimental grid in EPGC is a fully functional power system, which enables companies to test their solutions and validate their expectations in a real-life environment. The facility also has emulators that can simulate wind or solar conditions in any part of the world, and replicate the behavior and performance of renewable energy sources.
WEnergy Global’s Chief Executive and Founder Mr. Atem R. Ramsundersingh said that EPGC not only had the right expertise in solar power and energy management, but was also willing to negotiate contract and payment terms to suit the company’s budget and vision.
"This project wouldn't have been possible from a price-and-profit perspective if I had bought the parts from big companies, which may not be aware of the off-grid challenges in rural Asia, including the interface between regulatory frameworks and deployment of new technologies. It would have been like buying a Rolls Royce when all I needed was an e-bicycle," he said.
Meanwhile, WEnergy Global secured a second contract for a hybrid power plant on two Palawan islands that are worth USD 15 million. WEnergy Global has also developed a portfolio of such micro-grid and hybrid projects worth USD 250 million which will be executed in the coming years.
Narada Asia Pacific approached ASTAR’s Institute for Infocomm Research (I2R) in 2014, to explore how it could develop an integrated micro-grid system that combines solar photovoltaic energy generation with its REXC lead-carbon batteries. They eventually partnered on a joint-venture project, the Residential Photovoltaic Energy Storage System (PV ESS), together with the Singapore Housing Development Board & (HDB) and Singapore Power.
A complete micro-grid system was set up on the rooftops of selected HDB flats in Ang Mo Kio. Solar PV panels generated electricity for the flats, while Narada’s REXC lead-carbon battery served as a backup power source that supplied power and regulated electricity conversion and flow to the grid.
According to Narada’s director, Mr. Peter Ng, this joint-venture allowed the companyto access I2R’s solutions in advanced energy data analytics, complex system modelling and optimization technologies. I2R also helped to bring in partners like HDB and Singapore Power, providing test-bedding opportunities in actual scenarios.
The project has since sparked business opportunities for Narada locally and regionally, and provided a deployable solution that can be replicated in other Asian countries where stable utility grids are crucial to economic growth.
With increased energy demand across the region and high environmental costs associated with fossil fuel usage, investing in micro-grid innovation is a viable route for companies to tap the vast potential of renewable energy.
Companies looking to harness the potential of micro-grids can approach EPGC or the recently launched ASTAR Industrial Smart Grid Consortium. Under the Consortium, companies can work bilaterally with ASTAR to leverage the technological capabilities of its research institutes to conduct research and development.
For more information on partnering ASTAR on micro-grid solutions, please contact:
Illustration Photo: Two 130W peak PV Panels convert solar energy into electric power which is stored in the battery via a charge controller. An inverter is used to convert the 12V DC supply from battery into 230V AC which is passed through the timer switch. This is a programmable switch which automatically starts and shuts off power supply to customers at pre-set times. The distribution panel helps to split the grid into 4 circuits that cover household clusters located around the powerhouse reducing risk to the system while increasing overall efficiency of the grid. Power limiters are used to regulate the flow of power through each of the distribution circuits, its function is to temporarily cut-off power supply in case of any misuse or over-drawing of energy which could harm the system. (credits: Soneva Foundation / Flickr Creative Attribution-NonCommercial 2.0 Generic (CC BY-NC 2.0))