Climate change is one of the world’s leading existential threats, and governments and business leaders globally are working hard towards reducing and eventually eliminating carbon emissions. 

To achieve this, the energy sector is looking to adopt more and more innovative low-carbon energy technologies. Over the course of two articles, we will explore six game-changing technologies that are likely to shape our future:

1. Offshore renewable energy

2. Energy storage

3. High voltage direct current

4. Green hydrogen

5. Carbon capture, utilisation and storage

6. Nuclear fusion

In the near-term, floating wind and solar, energy storage and high voltage direct current (HVDC) are all technologies that exist, but have yet to be fully commercialised. It is predicted that we will begin to see the impact of these technologies by 2030. 

One example of innovation in energy storage is liquid air energy storage, or LAES, which uses excess energy to clean, compress, and cool air (about 78% of air is nitrogen) to -196°C. The liquified air is stored in insulated tanks at low pressure. When energy is needed, the liquid air is drawn from the tanks and pumped to high pressure, reheated, and expanded, resulting in a high-pressure gas which is used to drive turbines to generate energy. LAES is a unique solution to provide low-cost, large-scale, long-duration energy storage with no geographical constraints. It can also harness waste heat or waste cold in the system to further increase the overall efficiency.

This system is currently in operation at the Highview Power Storage in Vermont in the US. This facility provides at least 50MW and eight hours of energy storage (i.e., 400MWh). It is the first long-duration LAES system in the US and is the first of a batch of planned utility-scale LAES projects being developed across the country to help scale up renewable energy deployment.

3. High voltage direct current 

Power transmission is a key element to harness bulk wind and solar energy which are only available in remote locations. High Voltage Direct Current (HVDC) technology is not new, but advancements in power electronics and rapid deployments of HVDC transmission systems around the world since 2000 have enabled countries to tap into their sustainable resources such as solar and wind power using HVDC transmission lines. 

Compared to Alternating Current (AC) system, the High Voltage Direct Current (HVDC) system is more economical to build and maintain for bulk power transmission given a long distance. HVDC cables can be more economical for underground and underwater applications, and can also be used to interconnect asynchronous grids. With growing demand for massive renewable energy integration, reinforcing the stability and reliability of the grid, and global energy interconnection, the potential of utilising more HVDC power transmission systems is immense.

Ultra-high voltage direct current (UHVDC) is one of the most rapid developments in HVDC transmission systems. A UHVDC network is capable of supporting DC voltage transmission of above 800 kV, whereas a HVDC network generally operates at a voltage of between 100 to 800 kV. The higher the voltage, the more electricity the line can carry and the lesser transmission losses. 

For instance, China has built a number of UHVDC lines integrated with their UHV AC systems to enable the transmission of massive solar and wind power generated in north western China to the load centres in eastern China, spanning a distance of over 1,000 kilometres across several provinces. Estimates suggest these projects will reduce carbon emissions by approximately 30 million tonnes a year, equivalent to taking more than six million cars off the road.