
The Semakau Island Landfill, located about 8km south of Singapore’s main island, takes in about 200,000 tonnes of solid waste a year, earning it the unceremonious title of “the rubbish dump of Singapore”. But the island is much more than a resting place for refuse. Today, it is also home to fish hatcheries and nurseries. It is known for its rich marine biodiversity and picturesque views. In addition, it may hold the key to energy security for remote villages and tiny islands.
On a recent Monday afternoon, Hans Bjorn Puttgen leads a group of reporters to a near-empty plot of land on the island. The 64,000 sq m space, roughly the size of eight soccer fields, currently boasts just a row of photovoltaic panels. But it will soon be the site of four hybrid microgrids that will tap solar, tidal, diesel and power-to-gas technologies, Puttgen says. The first phase of the project has been completed, with more than 3,000 sq m of photovoltaic panels installed on the rooftop of the transfer building, where barges berth.
Puttgen is a professor at the Nanyang Technological University and senior director of its Energy Research Institute. He heads a team of NTU scientists who are working to put together a largescale integrated offshore renewable energy system on Semakau. Dubbed the Renewable Energy Integration Demonstrator- Singapore (REIDS) initiative, it will be the first such project in Southeast Asia.
Other members of the REIDS consortium include ENGIE Lab Singapore, a unit of French energy utility ENGIE; energy management and automation solutions provider Schneider Electric; energy solutions provider General Electric Grid Solutions, a unit of GE; and utility operator Sembcorp Industries.
When completed in the third quarter of next year, the four microgrids will be capable of managing multiple renewable energy sources. They can be operated independently or collectively. Once fully operational, the microgrids are expected to power fish hatcheries and nurseries at Semakau Landfill. In the medium term, the goal is to produce enough stable and consistent energy to power 250 four-room high-rise apartments for a year.
The project will serve as a test-bed to demonstrate how renewable energy- powered microgrids can operate reliably and inexpensively in a fully isolated environment. The island was chosen because it is isolated from an energy point of view, thus simulating the kind of environment typically found in remote villages and islands, says Puttgen.
Etienne Drouet, director of ENGIE Lab Singapore, says the ultimate goal is to commercialise the integrated product in Asia-Pacific, particularly in the Philippines and Indonesia. These are markets in which ENGIE is already supplying off-grid solutions. “But, in two years, we want to supply the next generation of energy management systems to them,” he says.
Off-grid requirements
Globally, as many as 1.2 billion people do not have access to electricity. More than 95% of this underserved population live in sub-Saharan Africa, Latin America and Southeast Asia. Typically, they live in remote areas that are not connected to national power grids. Remote communities lucky enough to have access to electricity rely on diesel generators, which are expensive and harmful to the environment.
For companies in the energy business, this off-grid market represents tremendous opportunity. In Asia-Pacific alone, it is expected to grow at a compound annual rate of 31.3% from 2013 to 2023. By then, it will be valued at $5.6 billion.
The solution, it would seem, is renewable energy, but off-grid renewable energy systems pose several challenges. One is stability. Winds and waves do not generate the same amount of power at all times, and even the sun is sometimes clouded over. Grid technologies today work best on stable and continuous power generation, which renewable energy systems throw off. Adding variable load factors further complicates matters. If demand surges just as energy production plunges, stored power can be depleted quickly, leading to a power outage.
At Semakau, ENGIE and Schneider have co-developed a common energy management solution to integrate the various renewable energy sources with a portfolio of storage systems. They will also use hydrogen as an energy source, to smooth out lumpy output or fulfil any temporary increase in the load profile. The hydrogen chain will include a low-temperature hydrogen generator, storage for the hydrogen generated and a fuel cell for converting the stored hydrogen into electrical energy. A hydrogen refuelling station will be constructed and interfaced with the hydrogen cycle to fuel electric vehicles such as forklifts, light vans or scooters.
The project relies on predictive algorithm to forecast load demands and the available supply of renewable energy sources. It uses data from weather forecasts as well as consumption and production profiles to ensure a more accurate forecast. The system will monitor real-time fluctuations in output and demand, so that timely adjustments can be made.
Another useful addition is a Demand Response feature, which controls when energy is dispatched for a specific use. Drouet cites the example of an ice factory that typically has to run eight hours a day. With the Demand Response feature, those eight hours of power can be dispatched at a point that works best for the microgrid. In other words, the microgrid will be able to determine where the needs for power are the highest and channel electricity there. Conversely, should the microgrid determine that a specific load is not of a high priority, it can delay dispatching electricity till the overall load demand on the grid is lower.
Of course, that means not every customer will have power when he needs it. “There will be occasions when optimisation of an individual sub-system must be sacrificed to optimise the whole system,” says Drouet.
Commercial deployment
Drouet acknowledges that, even if the REIDS initiative proves successful, deploying it in other markets will be difficult. The solution requires not only acceptance by the local community, but also what he calls “a first level of independence” by the local community. This involves equipping them with the relevant skills and knowledge to operate the system.
Inevitably, there will be questions about reliability too. He cites a recent sociological study done in the Philippines. “The first question the locals asked us was whether our system was typhoon-proof. Given that the Philippines is prone to typhoons and has suffered severe damage in recent years, it is important that we build a system that the local communities have confidence in,” says Drouet.
Nevertheless, the project has had a promising start. And the Semakau Island Landfill, previously little more than a wasteland and a nature reserve, has Photovoltaic panels installed at Semakau Island Landfill an interesting future.
This article appeared in the Enterprise of Issue 757 (Dec 5) of The Edge Singapore.