Scientific carbon reduction should achieve the lowest total cost for the whole society, the smallest economic cost, and the best process. For the sake of carbon neutrality, we should not focus our firepower on all high-carbon industries to fight a war of annihilation or mobile warfare. In the current process of carbon neutrality, the relationship between new energy and coal-fired thermal power units should be complementary, interdependent, symbiotic and co-prosperous, rather than a zero-sum game where mutual growth and restraint exist.
Viewpoint: New energy and coal-fired thermal power should complement each other and co-exist and co-prosper
Domestic professionals engaged in thermal power technology and economic evaluation generally like to use the cost of electricity to evaluate the economics of a project. The basic concept of cost of electricity is the unit cost of electricity generation, that is, the total cost divided by the total power generation during the operation period. The cost per unit of electricity can be roughly divided into fixed costs and variable costs. Fixed costs include depreciation of fixed capital, amortization of intangible assets, repair costs and financial expenses, etc.; variable costs include fuel costs, water costs, material costs, desulfurizers, denitrification agents, etc.
International energy organizations such as the International Energy Agency (IEA) prefer to use LCOE to evaluate the complete power generation cost of investment projects. LCOE is the levelized cost of electricity, that is, the cost per degree of electricity from the whole life cycle (including the construction period and operation period). The total cost in the whole life cycle (the sum of the present value of all costs, mainly including the original investment cost, operating cost and residual value) is divided by the total power generation (the sum of the present value).
After new energy parity, the importance of coal power remains
LCOE is often used for cost benchmarking of thermal power and new energy. According to relevant data from the International Renewable Energy Agency, the global average photovoltaic levelized cost of electricity has dropped by 82% in ten years, from 37.8 cents/kWh in 2010 to 6.8 cents/kWh in 2019. At present, China's photovoltaic LCOE is close to or even lower than the coal-fired grid electricity benchmark price, and it will be a high probability event that the photovoltaic wind power LCOE will be lower than the coal power LCOE. In addition, according to the International Energy Agency, the LCOE of wind power fell by 83% from 1983 to 2019. Based on the above experience and judgment, some energy researchers believe that new energy sources such as scenery can replace traditional energy sources, especially coal-fired thermal power is just around the corner.
After years of government subsidies and strong support, wind power and photovoltaic power generation can finally be connected to the grid at a par. Preferential policies such as full purchase of power grids and priority access to the Internet have given new energy solid confidence. The double-high (high pollution, high emission) project coal power units that are born with original sins seem to have completely lost their competitiveness.
However, judging from the current energy technology and market reality, new energy + energy storage cannot become a substitute for fossil energy or coal power. Back then, because of the randomness, intermittency, and volatility of new energy sources such as wind power and photovoltaics, there was no time when it was not needed, and there was no time when it was not needed. . To date, this problem has not been fundamentally resolved.
The cold wave power outage in Texas in February 2021, the orderly power consumption in some provinces in China from the end of 2020 to the beginning of 2021, and the power cuts in many places in China starting in the third quarter of 2021 are all behind the insufficient effective installed capacity. question.
As we all know, although the installed capacity of new energy is huge, the equivalent effective capacity is too low. The resistance coefficient of wind power is close to 95%, and the resistance coefficient of photovoltaic is 100% (daytime, night). When calculating power balance, people in the industry know that the effective coefficient of wind (light) and other new energy sources is only considered at 5% (0%), especially during the peak hours of winter and summer, when there is almost no wind.
In contrast, the average resistance coefficient of conventional coal-fired thermal power is about 8% (15% for heating units), and 40% for hydropower. To further explain in plain language, because of the low effective capacity of new energy sources such as wind and solar, before large-scale, long-term energy storage technology maturity, safety, and economics have not achieved substantial breakthroughs, it will be used in the whole society. Under the premise of maintaining a certain growth rate of electricity, the more renewable energy such as wind and solar energy is installed, if the traditional power supply cannot be built synchronously and maintain a corresponding increase, the entire power system will be in short supply in winter and summer peaks and extreme climates. electricity. This is the root cause of frequent electricity shortages.
It can be seen that it is not an exaggeration to compare coal-fired thermal power units to the ballast stone and stabilizer of the power system at this stage.
At critical moments and in times of crisis, only the disliked coal-fired power units can stand up and carry them, and become the mainstay of energy supply. Some people may think that this is only a small probability event, how can it happen every day? However, in the south where the extreme cold and no light, the extreme heat and no wind, and a high proportion of hydropower, the dry season in winter and the extremely cold weather lack both wind and light. Water will become a frequent high probability event. In 2008, 2020, and 2021, extremely cold and low temperature weather occurred frequently. In addition, the current limited UHV channels are still difficult to realize the interconnection of electricity between provinces across the country, mutual adjustment, and complementarity.
The frequent occurrence of extreme weather has warned people again and again to put all their energy security on the intermittence and volatility of scenery, etc., and have distinct seasonal characteristics (the rainy season in the middle and lower reaches of the Yangtze River has a long dark period, summer Long-term windless and less windy periods) on new energy sources may lead to large-scale power outages. This feature of new energy requires a large number of adjustable power sources to maintain stability and rebalance for the characteristics of intermittent, fluctuating and power shortage. As a manager of the energy sector, he should have a deep understanding of this and make emergency plans for power security and supply.
With the frequent occurrence of such extreme weather conditions, ensuring energy security is the top priority of domestic people's livelihood (especially in the "Three North" region, winter heating is the top priority of people's livelihood, no less than food security). At that time, neither old renewable energy sources such as hydropower nor new renewable energy sources such as wind and solar power could be mentioned. Only traditional fossil power sources (thermal power, gas power) and nuclear power could guarantee energy security.
Limitations of LCOEs
The replacement of fossil energy by new energy should not only consider the stability of the power grid, but also many economic and social issues. After the "Three North" region enters the severe winter season, heating and power supply has become the first priority of people's livelihood, and the energy utilization efficiency of combined heat and power is the highest. New energy can only generate electricity without heating. If the heating has to be converted from electricity to heat, the efficiency of energy utilization will be significantly reduced. If you don't consider it from the perspective of carbon reduction and carbon reduction, the thermal efficiency of cogeneration is the highest. In contrast, hydrogen production after new energy power generation reduces the energy efficiency by half, and then transports, stores hydrogen, and then generates heat for heating, and the efficiency is reduced by half again. The energy conversion efficiency is too low and the energy loss is serious. If it is considered that new energy is equipped with long-term energy storage (weekly and seasonal energy storage that exceeds daytime energy storage), the LCOE of new energy will rise sharply, and its economic advantages will disappear.
At present, all provinces (regions) across the country have issued policies one after another, requiring new energy projects to be equipped with 10% to 15% energy storage as standard, and the duration is about 1 to 2 hours. Renewable energy investment projects with good project benefits, plus this 10%~ 15%, 1 to 2 hours of energy storage configuration, the investment benefit has already begun to deteriorate, and it is close to the break-even point. If it is equipped with long-term energy storage for more than one day, under the current technical, economic and market conditions, it is difficult to imagine that a wind and new energy investment project can be profitable.
In the past year, the topic of hydrogen energy has been hot, and it has even been called the ultimate energy source in the 21st century. So will hydrogen energy be the key factor to solve the short board of new energy? This is probably not optimistic. Due to problems such as low energy conversion efficiency, high cost, infrastructure investment and safety, there is no hope for large-scale development of hydrogen energy within ten years. Even in 2050, experts are still not completely sure that hydrogen energy will replace traditional fossil energy in the field of transportation, let alone other industries?
In addition, there are still many technical difficulties in hydrogen energy, and the key core components have not yet been localized... These bottleneck problems need to be resolved urgently. Although countries around the world vigorously advocate and actively promote it, the development of hydrogen energy is still in the market introduction period, and the entire industrial chain does not have a cost advantage. Its large-scale development is on the way, and all problems are solved during development. This period is at least ten years or longer. After the technology and market are both mature, hydrogen energy will be promoted and applied on a large scale.
From this point of view, evaluating the cost of various power generation sources only from LOCE is obviously a generalization and a glimpse of the leopard. New energy enjoys various preferential policies and measures of the power grid (such as priority access to the Internet and full purchase, etc.), but has not undertaken the corresponding basic obligations such as peak regulation and frequency regulation and provision of effective capacity. Just like in a society ruled by law, every citizen should assume their own obligations while enjoying their rights. This should also be the case in the market-oriented power industry. Before the complete marketization of the power industry, the type of new energy power generation has not achieved the unity of responsibility, power and benefit. A senior professional in the power circle vividly compared, whoever hires a full-time nanny will hire a willful and coquettish little girl, who can do what she wants, and don’t do what she doesn’t want?
In addition, after a large number of random and highly volatile new energy sources are connected to the grid for power generation, they will have a huge impact and impact on the grid. It is difficult to maintain the power balance of the power system, which is a worldwide problem. In addition, the traditional power grid needs to provide a moment of inertia and a strong supporting power supply, otherwise the security of the power grid will not be guaranteed. These cannot be guaranteed by intermittent power sources such as wind power and photovoltaics, and can only be guaranteed by traditional power sources. In addition, due to the high proportion of new energy installed capacity, the problem of frequent subsynchronous oscillations in the Northwest Power Grid has not been effectively and completely resolved so far.
Perfect Cost Calculation
To sum up, it is one-sided to only consider LCOE for the power generation cost of new energy such as wind and solar. The real full cost of new energy power should be added to the power system cost that new energy should bear. The cost of the power system is the cost of energy storage, and ensuring the security of the power grid cannot only be borne by the power grid enterprises and the current main power generation-coal-fired thermal power units. While enjoying the rights, new energy enterprises must undertake the corresponding obligations. This is a scientific, rational and pragmatic attitude.
Similarly, the current LCOE for evaluating thermal power sources is not comprehensive and scientific, especially in the cost of coal-fired thermal power, which does not consider its environmental cost. The LCOE of thermal power plus its environmental cost (that is, carbon price or carbon tax) is the complete cost of thermal power.
At present, China's carbon market has just started, and the overall level of carbon price remains at around 50 yuan/ton. The carbon price does not fully reflect the environmental costs caused by the high pollution and high emission characteristics of coal-fired thermal power units. From the perspective of international trends, the carbon price in Europe is approaching 100 euros/ton and will fluctuate in the range of 60-100 euros/ton. European coal-fired thermal power units must pay high environmental costs if they want to survive. In this way, the market will force coal-fired thermal power units to withdraw from market competition due to high costs, without administrative orders.
While coal-fired thermal power units have not yet fully borne the environmental costs, China's new energy sources such as wind and solar are far from bearing the power system costs they should bear. Only some provinces such as the "Three North" region have established ancillary service markets. The service market is far from being established, and the effective capacity market has not yet started.
Insiders in the power industry have been calling for a two-part electricity price for thermal power units, and the capacity electricity price has not been implemented so far. Southwest hydropower provinces, such as Sichuan and Yunnan, do not have coal-fired thermal power as an important supplement during the winter dry season. It is estimated that people in the province will have difficulty in ensuring electricity consumption. In addition, Sichuan Province has implemented water and fire subsidies for many years, because local governments often default on subsidy funds for thermal power units, resulting in perennial losses for coal-fired thermal power units in the province. Ultimately, the root cause is the lack of system design in the marketization of electricity, that is, the electricity capacity market has not been established in time.
Considering China's coal-based resource endowment characteristics, the carbon price in the carbon market should not be too high before new energy sources become the main power supply. If the carbon price is too high at this stage, it may affect energy security and electricity consumption for people's livelihood. Rome was not built in a day, and the price of carbon in Europe did not soar to 100 euros immediately after the establishment of the carbon market. The European carbon market has also experienced nearly 20 years from its establishment to maturity. Therefore, the establishment and improvement of China's carbon market should most likely be a slow and gradual process from low to high carbon prices, rather than immediately aligning with European carbon prices.
In addition, Europe and the United States have completed industrialization, and their power consumption structure is dominated by the tertiary industry, supplemented by secondary and primary industries. The annual increase in electricity consumption is not large, and the total amount is basically stable. While China is in the process of industrialization, during the period of the 14th Five-Year Plan and the 15th Five-Year Plan, the annual growth rate of electricity consumption will still maintain a medium-to-high growth rate. The current power consumption structure is dominated by the secondary industry, supplemented by the primary and tertiary industries.
In terms of electricity consumption increment and electricity consumption structure of the whole society, there are big differences between Europe and the United States and China, and the experience of carbon neutrality in Europe and the United States cannot be completely copied. Of course, the electricity consumption of China's whole society is relatively high, mainly because China's energy consumption per unit of GDP is too high (higher than the world average level, about twice that of developed countries such as the United Kingdom). The root cause is that the heavy chemical industry has obvious characteristics, some high energy-consuming industries have relatively excess capacity, and technology is relatively backward. As a result, China still has a long way to go on the road of energy conservation and emission reduction.
During this period, coal-fired thermal power and new energy complement each other and are indispensable, rather than life and death. Only by eliminating coal-fired thermal power units, new energy sources such as wind and solar can gain a broader space for survival and development. At present, this kind of thinking is too eager for quick success.
In the current dual-carbon process, the relationship between new energy and coal-fired thermal power units should be complementary, interdependent, symbiotic and co-prosperous, rather than a zero-sum game where mutual generation and restraint exist.
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