To overcome the global imbalance of renewable energy resources and the limitations of conventional fossil fuels, supergrids – continent-scale power grids – have been proposed as a key to the transition to a new energy regime, especially in resource-poor countries such as South Korea.
Petroleum reserves are finite and becoming increasingly unprofitable over time. Nuclear power, which has been touted as the next generation of energy, is losing credibility due to a series of nuclear accidents and waste disposal issues. Under these circumstances, it is increasingly necessary to transition from the current energy system based on fossil fuels and nuclear power to one based on renewable and clean energy. However, the transition to an energy system based on renewable energy is very challenging. For one thing, renewable energy sources themselves lag behind fossil fuels, our primary energy source, in many ways. Their supply is less reliable, they are not easily stored, and they pose challenges in many ways. Countries with large land masses and abundant clean energy resources, such as China, Mongolia, and Russia, are somewhat better off, but countries with small land masses and scarce clean energy resources, such as South Korea, have a more unfavorable outlook. In this situation, a “super grid,” a continental-scale interconnected power grid, is being recognized as a key to transforming the energy system. But what exactly is a super grid, and what role can we expect it to play in the transition to a new energy system?
A super grid is a continental-scale power grid created by connecting smart grids between countries. In this context, a smart grid is a next-generation power grid designed to complement the efficiency of the existing power grid, incorporating information and communications technology to allow power suppliers and consumers to exchange information in real time, enabling more resilient power supply and consumption. Electricity is one of the most difficult energy resources to store, and the economics of storing it drops dramatically. Therefore, production and consumption must always be simultaneous. Currently, the grid produces more than 10% of the expected consumption as a reserve for unexpected events, and most of this power is wasted. This is a significant waste of energy, and with a smart grid, the grid can communicate with both the consumer and the producer in real time to determine the demand for electricity and generate only as much electricity as needed, saving energy. Examples of super grids include the Nordic-EU SuperGrid, the Southern Europe and North Africa-Middle East SuperGrid (Sud EU-Magherb SuperGrid), and the Southern Africa Grid (Grand Inga Project).
High-voltage direct current (HVDC) technology has made it possible to build power grids between countries separated by thousands of kilometers. In fact, since the commercialization of electrical energy, alternating current power has been preferred over direct current power to transmit electricity. In the case of alternating current power, reactive power is generated due to the phase difference between the current and voltage, resulting in power loss, and the transmission efficiency is reduced due to the increased reactance caused by electromagnetic induction and the surface effect due to the nature of alternating current. On the other hand, direct current power is free from reactive power, electromagnetic induction, and skin effect because the direction of the current does not change, and the number of wires required for transmission is small, resulting in high transmission efficiency. However, direct current’s fatal flaw is that it is difficult to transform. While alternating current can be easily regulated with a simple transformer, direct current requires complex technology and devices to transform. Alternating current has been preferred over direct current because the voltage needs to be raised to minimize losses during transmission. However, alternating current is not very efficient, and its economic efficiency decreases significantly as the transmission distance increases, which hinders the development of super grids based on long-distance transmission. HVDC technology is the solution to this problem. Simply put, HVDC is a technology that converts electric power into alternating current when transforming it and direct current when transmitting it, utilizing the advantages of both alternating current and direct current. This has greatly improved the economics of long-distance power transmission, and as a result, the idea of a supergrid – a continental-scale, cross-border power grid – is no longer a pipe dream, but a viable model.
So, why are these interconnected super grids necessary to transform our energy system? The main reason is that renewable energy can overcome the poor storage capabilities of fossil fuels. Both fossil fuels and renewable energy tend to be concentrated in certain regions. In South Korea, renewable energy resources are not abundant. It lacks large plains suitable for solar power, and while it is windy enough for wind power, the wind direction is inconsistent. Mongolia, on the other hand, boasts 1,110 TWh of wind power and 1,500 TWh of solar power per year. That’s a lot more than South Korea’s total electricity production of 526 TWh in 2016. While fossil fuels can be transported to where they are needed and generated, renewable energy has a major weakness in that electricity must be consumed at the same time it is produced. Energy needs to be delivered as soon as it is demanded, and in a system based on renewable energy, the current grid may not be able to deliver it. This is because the places of production and consumption are far apart. However, a successful super grid could solve this problem. A continental-scale, cross-border power grid can connect energy producers and consumers into a single grid that can seamlessly deliver power to where it is needed.
South Korea is working with Mongolia, Russia, China, and Japan on a project called the Northeast Asia Super Grid. As mentioned earlier, Korea does not have abundant renewable energy resources and its electricity demand is high compared to other countries, making a super grid particularly important for a renewable energy-based system to be successful. However, the current “Northeast Asia Super Grid” faces a number of challenges. The first is that the basic infrastructure to build a super grid is still largely lacking. In Korea alone, even smart grids are considered premature due to the high initial investment costs. For a super grid to be successful, thousands of kilometers of smart grids across five countries would need to be formed. Some of these countries have not been developed at all, such as Mongolia and eastern Russia, making the initial investment even more burdensome. The second problem is that for the Northeast Asian Super Grid to be successful, the interests of the five countries must be well aligned. Northeast Asia is still a region of complex interests, and any tensions between countries during the operation of the super grid could lead to an energy war and disruption of power supply. However, there is also a view that this downside could be mitigated by the super grid. According to the current blueprint, the super grid does not pass through North Korea, but in the future, passing through North Korea could ease tensions on the Korean Peninsula, and there is also the possibility of various economic cooperation through the sharing of energy systems among the five countries.
The Northeast Asia Super Grid still faces many challenges. South Korea is the ninth largest energy consumer in the world. However, it is also an energy-poor country, generating 86.5% of its energy from fossil fuels and nuclear power, and importing 96% of its energy resources from abroad. In this reality, the Northeast Asia Super Grid project is expected to be essential for the successful transition of Korea’s energy system, which lacks abundant clean energy resources, despite the aforementioned problems.
