The role of coal-fired power in the national energy system

Coal-fired thermal power in Vietnam dates back to 1925 (the anti-French period), was the Yen Phu power plant, then developed more factories: Cam Street, Hai Phong, Hon Gai, Lao Cai, Ham Rong, Vinh. , Viet Tri, Uong Bi ... total electricity capacity of about 100 MW (largest in Southeast Asia at that time).

Then, in the early 1970s, Vietnam developed more coal-fired power projects (NDT): Ninh Binh (100 MW); in 1975 and 1976, Uong Bi investor was expanded (153 MW); Early 1980s: Pha Lai 1 investor (440 MW), etc ...

Coal-fired thermal power during the anti-French and anti-American period was the power source with the Vietnamese people, defeated the French enemy, overcame the American enemy, and served as a solid back-end for the resistance in the South. From 1971 to 1994, in the North built hydroelectric power plants: Thac Ba (1971), Hoa Binh (1986); In the South there is Tri An hydropower (1991), supplementing the national electricity system.

Over 30 years of renovation, coal-fired thermal power has contributed hundreds of billions of kWh every year to the country's socio-economic development with today's results.

Up to now, in 2019, the total electricity capacity of the whole country reached 54,880 MW, of which 20,200 MW coal-fired power accounted for 36.1%, but it has a very high value in generating electricity. The output generated by coal-fired thermal power accounts for 150 billion kWh out of the total of 231 billion kWh of electricity in Vietnam for the whole year. Because coal-fired thermal power is a stable source of electricity all year round, the number of hours is up to 7,000 hours / year, due to lack of electricity, so often operating up to 8,000 hours / year, currently no power source has achieved a record. so.

With countries around the world, the number of 20,200 MW of coal-fired power in Vietnam is still small.

Currently, coal-fired thermal power is present in 77 countries (in 2000 this figure was 65), 13 other countries are planning to develop coal-fired power. The world coal-fired power capacity nearly doubled in the period 2000 ÷ 2017, from 1,063GW to 1,995GW. The three countries with the largest total coal-fired power capacity in the world are China: 935GW, the United States: 279GW and India: 215GW; followed by: Germany: 50GW, Japan: 44.5GW, South Africa: 41.3GW, Korea: 38GW, Poland: 29GW and Indonesia: 28.6GW. Thus, Vietnam's total coal-fired power capacity is currently only 1.02% of the world's total coal power capacity in 2017.

Countries around the world, as well as Vietnam, in the early period of development of coal-fired power plants were all using old technology, low generating capacity, only using boilers with subcritical and subcritical steam parameters. Therefore, indicators of environmental pollution such as ash, slag, CO2, NO2, SOx are still high. Gradually, the technology developed, the installation of electrostatic dust filters to overcome the dust (preventing up to 99.8% of dust discharged) and introduced the supercritical boiler technology, along with the installation of the equipment. being reduced from SO2, NOx has been able to limit a lot of dust, ash, slag and other toxic substances.

Up to now, during the Fourth Industrial Revolution, some advanced countries such as Japan, Germany, France ... have switched to building "super supercritical" and "super supercritical" and "super super-super" coal-fired thermal power plants. Advanced term ”(Ultra-Supercritical and Advanced Ultra-Supercritical). Many coal-fired power plants have limited emissions of harmful gases, due to high boiler efficiency, high calorific value of coal, so the amount of ash and slag is much reduced and CO2, SO2, NOx emissions. also get a 20% discount.

In order to overcome and maximize the reduction of environmental pollution of coal-fired power, in addition to the solution of using supercritical and "super supercritical" boilers, external equipment can be installed to reduce CO2 substances. , SO2, NOx. This is nearly 20 years ago, Vietnam has applied for Pha Lai 2 Thermal Power Plant (600 MW) using technology from UK, Japan and America, since then, it has been operating well.

In Power Plan VII (adjusted), from now to 2030, there are about 10 projects with a total capacity of 14,600 MW that may be rejected for many reasons that cannot be implemented, the remaining 18 coal-fired thermal power projects are underway. construction and investment preparation. If those 18 projects are completed, it will increase the capacity of investors by 21,200 MW, along with current investors (20,200 MW), the total coal-fired thermal power will reach 41,400 MW. In the total installed capacity of power sources in 2030 is expected to be 130,000 MW, coal-fired thermal power accounts for 31.8%, which is a modest percentage, down from the present.

Considering the balance of power sources by 2030, traditional power sources will play a key role, coal thermal power is expected to be about 31.8%, gas thermal power (including LNG) is about 29.2%, hydroelectricity 18%, renewable energy nearly 21%. However, by 2030, Vietnam still does not have backup power sources, if the economic development rate of the country with the current growth rate and higher.

Among the above power sources, coal-fired thermal power output in kWh has always accounted for the highest percentage, and nothing can be replaced. In recent years, Vietnam has built a number of coal-fired power plant projects using supercritical technologies such as Vinh Tan 2, Vinh Tan 4, Duyen Hai 3, Duyen Hai 2, Vung Ang. These projects have reduced emissions, toxic gas causing environmental pollution, only ash and slag still exists, because Vietnam imports coal dust 3, bran 4 from abroad to mix with coal dust 6 in In the country to become coal dust 5, used for factories using the supercritical technology mentioned above, but in coal dust 6 mixed with a lot of soil, sand, so the ash and slag still exists as much as: Vinh Tan 2, Vinh Tan 4 (extension) ... this needs to be fixed.

In the future, Vietnam should experimentally build a few coal-fired power plants using "supercritical" technology, possibly using Japanese or American technology, but Japanese technology. lower cost, only about 2,500 USD / kW (more expensive than supercritical technology about 500 USD / kW). When put into operation, it will be assessed practically by measuring the% reduction of CO2, NO2, SOx per 1m3 of exhaust gas. In case the level is not reduced to allow, then install external reducing devices to eliminate. This will ensure a reduction of environmental pollution. As for ash from the supercritical technology boiler, there is no problem of concern. Thus, if this technology is used, it is possible to develop an additional 10,000 MW of coal-fired power for the national power system in the years after 2030, ensuring national energy security.

The electricity price of "supercritical" power plants is similar to that of plants using LNG. Of course, whether coal-fired power or LNG is fueled is a problem that needs to be considered carefully. Because we have used the boiler "super supercritical", we have to use coal with high calorific value such as coal dust 3, bran 4, this type of coal must be imported.

In Power Plan VIII, it is advisable to balance and remove old technology coal-fired power plants that have been operating for more than 60 years, and replace new technology coal-fired power plants as analyzed above to suit the period. Industrial Revolution 4.0.

For renewable energy: Renewable energy sources such as solar power, wind power are power sources with natural potential, need to step by step maximize, this type of energy works to compensate peaks during peak hours. noon point in system operation; It is advisable to encourage the development of rooftop solar power, because this type of electricity is useful for households, and then sold to the electricity industry without causing complications for the national electricity system. As for offshore wind power, Vietnam has a coastline of 3,200 km, with many estuaries and beaches capable of producing offshore wind power, because offshore wind power has high wind speed (over 7m / s) enough to rotating turbines of 9.5 MW or more and the generation time is over 5,000 hours / year and can be generated 24/24 hours, this is an outstanding source of renewable energy, Vietnam should encourage development.

According to the calculations of the ThangLong Wind project (outside of Mui Ke Ga - Binh Thuan), the number of power generation hours of this project is up to 5,500 hours / year, with a capacity of 3,400 MW, a total investment of about 12 billion USD, when completing the generated electricity can reach 20 billion kWh / year.

History has affirmed the significance of coal-fired power and coal-fired power will still exist for a long time, playing an important role in ensuring national energy security for socio-economic development and service. people's life./.

Source: Vietnam Energy