Rajendra Iyer is the head of grid integration solutions within the Grid Solutions business unit at GE Renewable Energy. The Grid Integration Solutions division, comprised of high-voltage, direct current (HVDC) and flexible alternating current (AC) transmission systems technologies, designs and integrates transmission solutions. Iyer has a decade of HVDC and EPC project engineering knowledge and a decade of international management experience.
Julian Turner (JT): What exactly are super grids?
Rajendra Iyer (RI): A super grid, in my view, is a network of transmission systems successfully incorporating multiple high-voltage, direct current (HVDC) electric power transmission overlays. This allows us to utilise the existing electricity networks in a more efficient way, while enabling multidirectional energy flows and the participation of multiple energy sources.
A super grid is superimposed on the existing power network and supports it with reactive power, making it more efficient. One of the hallmarks of an HVDC system is that it actually pumps juice into the existing AC lines, creating the possibility for more power flow. Super grids don’t just happen overnight, however – they are constantly evolving.
JT: What are the key advantages of super grids compared with traditional electricity networks?
RI: A super grid must be robust, have elements of self-healing to a large extent, and, again, it has to be very efficient, driving market economics in a way that will bring prices down for all consumers.
In Europe, for example, there are already signs that a super grid is evolving. By utilising the various different generation sources – an excess of wind power in one location, an excess of hydro in another, plus retiring nuclear and coal plants – Europe is able to efficiently connect markets and levelise electricity prices.
The latest direct current (DC) technology allows utility companies to carry out detailed grid planning and formulate virtual contingency plans, reducing the need for costly and redundant power lines and infrastructure that are detrimental to the environment.
JT: What is unique about the concept of an Asian super grid and what are the hurdles to success?
RI: The Asian project is a different way of looking at super grids. It was developed in response to the retiring nuclear generation in the region, to develop an alternative source of base power using LNG, and to bring a large amount of renewable energy into the game.
I describe the super grid as a highway for levelising or making available renewable energy as part of the value chain in the multiple locations. It will make use of excess solar and wind in Mongolia, bring it all the way down to Japan through Russia, make it available throughout Japan using the existing networks there, then connect it to Korea and use Korea as an intermediate stop, before connecting to China and back to Mongolia again as part of one ring.
Electricity prices across these geographies range from very cheap to very expensive in Japan; the super grid will ensure there is a buffer in place to levelise shortfalls. The technology is what will enable this to happen, so that is not the potential hurdle here; rather it is the need for all the necessary regulatory framework to be in place and for the political climate to be conducive.
JT: How does DC technology work in the context of electricity super grids?
RI: HVDC technology is mature and one of its strengths is that it makes it possible to connect into regions that are not synchronised. In addition, the regions involved in the Asian super grid are divided by water, so you need to use cables, and that is also solved by today’s technology.
The other factor is that DC hybrids can work together with existing AC networks, which have fixed loads. Imagine a scenario when there is a sudden loss of an AC line due to a line fault, the rest of the grid becomes loaded, there is not enough supply capacity, and the frequency can drop. If the frequency drops below a certain point, the relays will simply start tripping other lines in a domino effect that can bring the entire grid down, resulting in blackouts.
However, if this is coordinated through a HVDC system in parallel or as part of the network, the control and protection system in the DC system automatically senses the problem and feeds extra power through the DC to maintain overall grid frequency. This is what I mean when say the self-healing aspect of super grids – one kick of life can save the whole network.
JT: How can super grids help to reduce CO2 emissions that harm the environment?
RI: Reducing emissions means retiring old fossil-based power generation and that can only be done with alternative sources of energy. The only option is to bring cheap and efficient renewable power from far away, and today you have DC technology that allows you to economically bring renewable power in over a distance of 3,000km.
Unlike AC, DC solutions can also be hidden underground with a cable, so you don’t have to cut down forests to build power infrastructure, so this is being embraced as the technology of the future.
JT: What are the main challenges facing the Asian super grid project and what will the electricity super grids of the future look like?
RI: In Europe, the transmission operators have come together to share their network data; it will be interesting to see if something similar can happen in Asia. There is a certain hesitation among the various players for national security reasons.
Another challenge, in some cases, is the reluctance of the grid operators. This is a mindset issue, a fear of change, but his can be overcome by discussion and collaboration, which is already happening.
GE is successfully deploying energy management systems into the grids that help operators to look at the grid behaviours, not only from a historical point of view, but also using the available data points to extrapolate how their grids will behave in the future, so relevant action can be taken in advance. All of this makes operators more open to bringing in the available DC technology.
Future energy management and storage systems will be intelligent and able to interact with the grid, and that includes consumers. Once smartphone energy management systems become a reality, we should, as a community, take the careful steps to design them and integrate them with the network.
As for the Asian super grid, it is doable, the technical groundwork has been done, and I believe the time has come for countries like Korea, Japan and China to take the necessary steps to deploy it.