Concerns of power grid disintegration and large-scale power outages if wind power and solar power increase strongly

According to the development orientation of power sources in 2031-2045, wind and solar power sources will be strongly promoted. Photo: Nguyen Thanh

Reduce coal power, increase renewable power

Compared with the revised power development planning VII (PDP7), in the period up to 2030, the draft national electricity development planning for 2021 - 2030, with a vision to 2045 (PDP8), which is being consulted by the MoIT, has made major changes in the power source development program.

Specifically, to develop wind and solar power sources on a large scale (wind power capacity will be three times higher and solar power will be nearly two times higher compared to the revised PDP7); and only build coal thermal power projects that are under construction and are promoting investment to start operation in 2021-2025.

The MoIT asked to strengthen wind power from a capacity of more than 600 MW in 2020 to 11,000-12,000 MW in 2025 and 18,000-19,000 MW in 2030. Also, its proportion will account for 11% and 13% of the total installed capacity in 2025 and in 2030, respectively.

The solar power will be strengthened from a capacity of about 17,000 MW in 2020-2025 to nearly 19,000-20,000 MW in 2030. Its proportion will account for 17% and 14% of the total installed capacity in 2025 and in 2030, respectively.

The structure of power capacity has a change in the direction of gradually reducing the proportion of coal thermal power from 34% in 2020 to 27% by 2030. In particular, in this period, no new coal thermal power plants will be developed except for plants that are under construction and are promoting investment to be able to operate in 2021-2025.

Instead, the MoIT wants to boost gas-using electricity from 7GW in 2020 to 13.5GW in 2025 and 28-33GW in 2030. Its proportion will increase from 15% in 2020 to 21-23% in 2030.

Based on the development orientation of power sources in 2031-2045, wind and solar power sources will also be enhanced, with the proportion of capacity reaching more than 42% by 2045.

Solve challenges

Although the orientation of promoting renewable energies such as wind and solar power has been clearly defined, the MoIT also stated this was an unstable energy source with strong impacts on the electricity system. With the characteristics of changing power generation capacity quickly and uncontrollably, wind power causes significant fluctuations to the electrical system every time it changes direction or stops blowing.

If other power sources are not invested for replacement at that time, or capacity of the existing power sources are not adjusted properly in time to compensate for wind and solar power, there will be an imbalance between power supply and load consumption.

“At that time, the voltage and frequency of the power system will slide out of the permissible norm and the technical protection systems will be impacted. As a result, the grid can be disconnected, and large-scale power outage will occur,” warned the MoIT.

Facing uncertainties of solar and wind power sources, the draft PDP8 stated other backup power sources were needed in case the wind and solar power sources change rapidly or suddenly stop.

To ensure safe operation of the electrical system without voltage and frequency drops, on the one hand, it is necessary to have an amount of available power equivalent to the total capacity of participating solar and wind power sources. Gas power will be promoted, ready to supply when solar and wind power suddenly decline.

On the other hand, to actively control alternative power sources, or solar and wind power when there is an abnormality, the electricity system operator should have measures, tools, and capacity to accurately predict changes of wind speed, changes in solar radiation within a day or week even when the backup power is sufficient.

The MoIT also proposed other measures to avoid negative and harmful impacts on the power system and promote the development of solar and wind power sources. Specifically, it is necessary to study how to install spare batteries and recharge in case solar and wind power sources exceed the load demand and generate electricity when these sources stop operating.