Integration of renewable energy into power systems
Being at the forefront of science and technology is not only exciting, it’s also challenging. Today, we at the Masdar Institute of Science and Technology are researching how to make mankind’s presence on earth more sustainable. And in the arena of sustainability, one of the most significant of issues is how we power our lives through electricity. Of the some 474 exajoules of energy that is estimated to have been consumed globally in 2008, some 14 percent was in the form of electricity, of which it is believed that up to 80-90 percent originated from the combustion of fossil fuels – a method of releasing energy that is blamed today for the global climate change that imperils our planet. Electricity, in short, has a huge role in modern life, and we currently still source most of it from unsustainable fuels.
It should be clear then that the need of the hour is to evolve mankind’s current electricity system, which is wasteful, inefficient and even environmentally damaging, to one that is intelligent, efficient, forward thinking and sustainable. Two parts in the electricity system that have been identified as being critical for this evolutionary process are the source of power, and its method of distribution. And that is why the research of my team and others at Masdar Institute is so crucial – we are investigating new and clean sources of energy, and also the systems needed to distribute their power conveniently, safely and economically.
As most people today know, part of evolving the electricity system to be more sustainable includes tapping into renewable energy sources like solar, wind, geothermal, biofuel and others. Today we have all seen some application of renewable energy – perhaps in the form of a solar powered bus station or from a towering wind turbine. But these renewable energy applications tend to be on a very small scale and currently only contribute to a fraction of the world’s electricity needs.
One of the big challenges to the global push towards sustainability is evolving renewable energy from one-off applications to where it is integrated into the grid systems that power our cities and developments. Masdar City, which is the clean-tech cluster of the Masdar initiative and the home of Masdar Institute, aims to be a pioneer in large-scale integration of distributed generation.
The reason for this current limitation is that traditional power grids were created to follow a basic array system. A utility provider had perhaps one or two remotely located power plants which, through thousands of miles of underground and overhead cabling, provided power to an area. The utility provider was the only source for power on the grid – with power flowing out from its core to various clients on its network through a system that tends to have around 10 percent of line losses.
But nowadays we are looking at microgrids, which are a group of micro-generators connected to the main utility grid. While before there may have been one or two sources of power on a grid, in our sustainable future, power will be generated from a host of sources – solar panels on an individual’s house, a windmill on school grounds, a biofuel cell at a dairy farm, etc. This will not only reduce dependence on conventional fossil fuel-sourced electricity, but also reduce line-losses, as the microgrid system puts the source and the user side-by-side, eliminating the need for the miles of cabling to get energy to a user. And a third potential benefit of the microgrid system – beyond the use of renewable energy and reduced line losses – can be in the form of wealth generation. With a feed-in tariff system, a homeowner whose solar panels collect more energy than he needs can sell it back to the shared network and turn a profit.
In order to make this idea a reality, scientists have to create the technology and systems needed to evolve our electricity system. To accommodate renewable energy technologies, reduce cost and improve efficiency, the existing grid has to undergo some serious changes that bring complications and sophistication to what was a very basic and limited system. Some of these challenges include voltage regulation, harmonics, protection coordination, islanding and etc. Studies related to the core technology of renewable energy micro-grids are required to assure safe, reliable cost-effective and efficient operation of the power system. The new power grid system needs to be evolved to handle the complexities and unique challenges of a future where individual houses and complexes may have their own solar panel on the roof or windmill in their backyard.
Dealing with those complications and adding the necessary sophistication is what Masdar Institute is hoping to address through innovative research. We are looking to provide systems needed to ensure microgrids can safely provide quality and dependable energy. Part of that includes the development of distribution system models that include distribution network models and renewable/distributed energy sources models. We will also be working to develop a control scheme for facilitating micro-grid operation. The study will then assess the impact of the integration of renewable energy sources such as wind, solar, fuel cells, etc in the form of micro-grids on distribution system protection and operation.
My own specialty is in islanding detection of renewable energy sources. I work in algorithms to create the software systems that lend the energy network the intelligence and sensitivity to detect distributed generation islanded operation. Islanding protection is one of our key areas of investigation for distribution system protection issues, as well as loss of coordination, nuisance fuse tripping, and loss of protective device sensitivity. New protection schemes will be proposed to overcome any negative impacts that could be imposed as a result of micro-grid operation.
We at Masdar Institute are doing the groundwork today to create the electricity system of tomorrow. It is our hope that with the support of the Abu Dhabi government and the hard work and brilliance of Masdar Institute’s professors and students, we can help make these dreams a reality.
Dr. Hatem Zeineldin is assistant professor of electrical power engineering at the Masdar Institute of Science and Technology.