The peak of electricity consumption in summer is coming. These "clever tricks" will protect electricity consumption

Summer is here, and with it comes the peak of electricity consumption. Faced with the once-a-year peak of summer electricity consumption, how do power companies ensure our electricity use?

Electricity consumption for cooling accounts for 30%

According to the "National Electricity Supply and Demand Situation Analysis and Forecast Report for the First Quarter of 2024" released by the China Electricity Council:

In terms of demand, the proportion of electricity load for cooling in China is about 30% in summer, and exceeds 40% in some areas. Summer temperature has become the main factor affecting the growth of electricity consumption.

The reason why electricity consumption peaks in summer is that, in the hot summer, 30% or even 40% of the electricity is used for cooling .

In summer, 30% of electricity is used for cooling, and this is for the whole country. But for an average household, it may be more than 30%. In many areas prone to high temperatures in summer, electricity used for cooling may account for about 50% of the total electricity consumption of households in summer.

Taking my home as an example, the proportion of electricity used for cooling in the total electricity consumption of the household in summer is very high, as shown in the following figure:

The picture shows the author's electricity consumption analysis in one year. June, July and August are the peak months for electricity consumption. The picture is from the author.

How do power companies deal with peak electricity consumption?

In fact, in order to ensure normal electricity use for the people, power-related units are continuously optimizing relevant measures every year to solve the problem of electricity shortage in summer.

There are many solutions, but among these solutions, let's first talk about a few that are easy to think of, such as:

Hydropower stations generate electricity during the day and less or no electricity at night, or even store water for energy.

Countless photovoltaic bases, wind power bases, and nuclear power units have been overhauled and maintained to ensure that they can maximize power generation during the peak electricity consumption period throughout the summer.

The above solutions are simple and easy to implement, but their impact is limited and they are not the core. The core lies in thermal power. Since June 2016, my country has officially launched the "thermal power flexibility transformation" pilot project.

The so-called "flexibility transformation of thermal power" refers to the transformation of thermal power to enable deep peak-shaving capabilities . Before the implementation of flexibility transformation, the minimum technical output of thermal power was generally only 50% to 60% of the rated output, and it could only be as low as 75% to 85% during the winter heating period. After the flexibility transformation, the minimum output of some units can be as low as 20%.

The benefits of this are enormous: when electricity consumption is at a low point and photovoltaic and wind power are generating large amounts of electricity, thermal power can smoothly transition from 100% output to 30% or even 20% output.

Whenever the peak electricity consumption in summer comes and the photovoltaic and wind power generation is greatly reduced due to weather reasons, thermal power can be quickly adjusted from 30% output to 100% output.

Since the flexibility transformation of thermal power plants, a large number of domestic thermal power units have acquired deep peak-shaving capabilities, and the newly built advanced thermal power units have deep peak-shaving capabilities from the moment they are born.

When the peak of electricity demand in summer arrives, a large number of thermal power units gradually transition from minimum output to maximum output. When night falls and electricity demand gradually decreases, many thermal power units slowly transition from maximum output to minimum output.

Cross-regional power allocation

One thing that needs attention is that electricity shortage in summer is sometimes not due to insufficient electricity production nationwide, but rather to local shortages caused by unexpected factors.

That is to say, even during the peak electricity consumption in summer, there are many places in the country with sufficient power generation capacity, while in other places, it is the insufficient power generation that causes the problem.

For example, in the summer of 2022, Sichuan experienced electricity shortage. The core reason was that Sichuan is a major hydropower province. In 2022, due to multiple factors such as continued high temperatures and dry water flows in major rivers, hydropower generation was insufficient.

It is difficult to predict whether the water flow in rivers will be dry in a certain year.

However, continuous improvement and optimization of the country's cross-regional and cross-provincial electricity allocation and the ability to complement and support each other in electricity can be achieved.

This is also what the power-related departments continue to do.

What we can do

In order to solve the peak electricity consumption in summer, the power-related departments are solving the problem in a targeted manner every year.

So, what can we, as ordinary people, do? There are many things we can do, but here we will only talk about the most effective and feasible way.

According to statistics released by the Ministry of Public Security, as of the end of September 2023, the national motor vehicle ownership reached 430 million, including 330 million cars and 18.21 million new energy vehicles.

For a family with a pure electric vehicle, the biggest electricity consumer in the home does not come from traditional appliances such as televisions and refrigerators, but the pure electric vehicle.

The choice of when to charge a pure electric vehicle is something that the owner can plan and choose, so it has good "executability".

Normally, the load on the power grid is lower in the morning and at night, and higher in the afternoon and evening.

If a large number of owners of pure electric vehicles choose to charge at noon or in the evening, then obviously this will aggravate the electricity shortage in summer.

On the contrary, if everyone chooses to charge in the morning or at night, it will be a beneficial behavior to reduce the power shortage in summer.

In addition, charging at night usually costs less. Therefore, when the peak of electricity consumption comes in summer, if a large number of new energy vehicle owners choose to charge at night or in the morning, it is a win-win behavior.

Author: Hanmu Diaomeng, a popular science writer and winner of the "National Excellent Popular Science Work Award" from the Ministry of Science and Technology

Reviewer: Xu Fei, Associate Researcher, Institute of Electrical Engineering, Chinese Academy of Sciences

Produced by: Science Popularization China