HVDC: A Solution to Integrate Renewable Energy into the Power Grid at Scale

The transmission power grid is a critical component of modern society, as it is responsible for distributing electricity from power plants to homes, businesses, and other customers. A well-functioning power grid is crucial for maintaining economic and social stability, as well as enabling access to essential services in our day-to-day life such as lighting, heating, and communication.

Okay, but the transmission power grid dates back to the late 19th century, Why should we care more about it now?

The answer is fairly simple, the way we used to generate the electricity has changed. Meaning that the infrastructure that a couple of centuries ago was built to transport the electricity from a few of big power plants to all types of electricity consumers, which could also adapt their electricity production based on the demand, is now becoming obsolete. The integration of renewable energy sources into the power grid changed completely the way we used to produce electricity. Renewable energy sources, such as wind and solar power, are often located far from population centers, making it more challenging to transmit the power they generate to customers.

As they are often located far from population centers, meaning that large amounts of power must be transmitted over long distances to reach consumers. This usually results in significant power losses due to transmission and distribution inefficiencies, which can offset some of the environmental benefits of using renewable energy sources.

The traditional transmission power grid uses Alternating Current (AC) technology, which requires power transformers to convert the voltage levels to match the needs of different customers. However, this system has limitations, such as energy losses during long-distance transmission and a lower maximum voltage capacity compared to Direct Current (DC) technology.

High-Voltage Direct Current (HVDC) has the potential to transform the current transmission power grid because of its superior performance compared to Alternating Current (AC) technology in several key areas. Here are some of the key benefits of HVDC technology:

1. Reduced Energy Losses: HVDC transmission is more efficient than AC transmission because it eliminates energy losses due to the conversion of voltage levels. With HVDC, electricity can be transmitted at higher voltages, reducing energy losses during transmission over long distances.
2. Integration of Renewable Energy Sources: HVDC is ideal for integrating renewable energy sources into the power grid. Renewable energy sources, such as wind and solar power, are typically located far from population centers, making it challenging to transmit the power they generate to customers. HVDC technology can overcome these transmission challenges, enabling the integration of renewable energy into the power grid.
3. Connectivity: HVDC technology allows for the connection of different power grids, enabling the exchange of electricity between countries or regions as it?allows the transfer of power between grid systems running at different frequencies, such as 50 Hz and 60 Hz. This can lead to a more robust and interconnected power grid, reducing the risk of widespread blackouts and improving energy security.
4. Enhanced Power Quality: HVDC transmission is less susceptible to power quality issues, such as voltage fluctuations and harmonic distortions, compared to AC transmission. This results in a more stable and reliable power supply for customers.
5. Improved Voltage Stability: HVDC transmission is less affected by changes in load conditions compared to AC transmission, leading to improved voltage stability. This results in a more reliable power supply for customers, reducing the risk of blackouts and power outages.
6. Lower Capital Costs: HVDC technology can be more cost-effective in some situations compared to AC transmission, as it can reduce the number of power transformers required and allows for the use of smaller, more cost-effective transmission lines.

The distance at which investing in HVDC is cheaper than AC technology can vary depending on several factors, including the cost of transmission lines, the efficiency of the transmission system, and the demand for electricity. But in general terms, for overhead lines, the break-even distance between DC lines and AC lines is around 600 km, while in underground lines, it is around 50 km. After these distances, it becomes cheaper to use DC transmission lines.

Recent market research , estimates the global HVDC Transmission System market size is to be worth USD 8921 million in 2021. And it is forecasted to reach a size of USD 14220 million by 2028 with a CAGR of 6.8% during the forecast period 2022-2028. Key market players include companies like ABB, Siemens, XD Group, NR Electric, GE Grid Solution, etc. In terms of global markets, China is the largest one, with a share about 46% followed by Europe, with a share about 17%.

It is clear that if we aim to transition to a society that will be strongly power with electricity, and this electricity will largely come from renewable sources, the power grid needs to evolve and innovative technologies such as HVDC have the potential to facilitate this upgrade. HVDC technology offers many benefits, including the integration of renewable energy, the ability to connect different power grids, and more efficient and cost-effective power transmission.

If you are interested in knowing more about this, I leave you here the link to a really interesting article I recently read.

• The Vital Link: How HVDC Is Modernizing the Grid (powermag.com)