Why can't we massively develop self-produced and self-consumed rooftop solar power?

05/13/2024 15:49

Assoc. Prof. Nguyen Viet Dung - Vice Principal of the School of Mechanical Engineering ( Hanoi University of Science and Technology) spoke at the consultation conference on the mechanism for developing self-produced and self-consumed rooftop solar power.

(PLVN) - Electricity sources have not increased much, but electricity demand has increased by about 10% per year. This will cause a shortage of electricity in the next few years. Self-produced and self-consumed rooftop solar power (SPP) is considered an opportunity to compensate for the current source. However, how to develop this source of electricity appropriately is a big problem. Associate Professor Nguyen Viet Dung - Vice Principal of the School of Mechanical Engineering (Hanoi University of Science and Technology) had an interview with the press on this issue.

* Sir, solar power is identified as a clean form of energy, so why can't this source of electricity be strongly developed?

- First of all, it must be made clear that energy is a form of matter that cannot be stored; the more it is produced, the more it must be consumed. In ideal conditions, the electricity output in the system must be balanced with the demand for use (electrical load). In cases where the electricity output is greater than the load, to store electricity, we must store it in artificial fuels such as batteries, accumulators, pumped-storage hydroelectricity, etc.

Solar power in general and rooftop solar power in particular have many advantages such as low installation and electricity production costs, and rooftop solar power has almost no cost in terms of installation area because it takes advantage of rooftops.

However, solar power has some insurmountable disadvantages such as the phase difference between demand and electricity output. Specifically, the time when solar power reaches its maximum output is usually at noon and the first half of the afternoon, but the peak time falls in the late afternoon (5-8 p.m., except Sunday). Not to mention, solar power depends a lot on the weather. For example, the system is generating at peak load of approximately 100% of the set capacity, just a passing cloud or a sudden rain, the output can be close to "0" in just a few dozen minutes.

That is why the development of renewable energy and solar power must always go hand in hand with the restructuring of traditional power sources such as thermal power (coal, gas, oil) and increasing the "smart, flexible" responsiveness of the power system dispatch to ensure the safety of the entire power grid system.

In Vietnam, to prioritize the use of renewable energy sources, thermal power plants are having to operate at low load, but at the same time must be ready to connect to the grid to compensate for the load during peak hours when there is no solar power, leading to low efficiency, high electricity production costs, reduced equipment durability, increased greenhouse gas emissions as well as other emissions into the environment. Therefore, solar power in general must be developed appropriately within the overall national power planning.

In Vietnam, in the period 2018-2022 alone, the ratio of total installed capacity of solar power compared to all other sources in the system increased from less than 1% to 20.5%. This rapid growth has put great pressure on the entire power system to ensure security and stable operation.

On the other hand, it must be said that although solar power is cheap, in general, in the entire power system, it will increase the production and operating costs of the entire system, due to reduced efficiency, increased fuel consumption, operating costs, and increased emissions for thermal power plants that were used to run baseload, but now have to run on renewable electricity. This is similar to buses that only run on routes and can carry a lot of people, but now have to make detours to pick up additional individual passengers, consuming a lot of fuel and increasing the risk of insecurity for the entire traffic network.

* So, in your opinion, at what level should the development of the National Target Program be appropriate?

- Currently, the Ministry of Industry and Trade is seeking opinions on the mechanism for self-produced and self-consumed solar power. The policy is designed to encourage the development of self-produced and self-consumed solar power to reduce the pressure to increase generation sources, thereby ensuring the electricity demand of society, especially during the hot season, as well as mobilizing social resources to participate in the electricity market.

However, connecting solar power to the national power system should only be temporarily limited to supplementing the electricity shortage when solar power does not produce electricity itself, and should not be bought and sold in the immediate period (about 5 years), so that relevant parties can make adjustments.

However, it is highly recommended to encourage the development of self-produced and self-consumed renewable energy in industrial parks. Therefore, in my opinion, it is necessary to add content on the use of non-grid-connected renewable energy in industrial parks and commercial service clusters (electric vehicle charging) in the Decree on developing self-produced and self-consumed renewable energy policies.

In addition, there should be incentives in remote areas and areas that need to develop renewable energy to offset demand when the national grid has not yet arrived or is difficult to meet the load demand; There should be a mechanism to encourage solar power with an energy storage system to minimize dependence on the grid; Unlimited incentives for solar power with storage devices that do not sell excess electricity to the grid...

Source: https://baophapluat.vn/vi-sao-khong-the-o-at-phat-trien-dien-mat-troi-mai-nha-tu-san-tu-tieu-post512312.html