New opportunities for biomass energy development in the context of carbon neutrality

The second is that biomass energy has not encountered transformational development opportunities before. The establishment of the goal of carbon neutrality has put forward a huge and urgent demand for systemic change in China's energy development in the future, which provides a rare opportunity for the further development and utilization of biomass energy. According to the energy ladder theory, the biomass energy used in this stage is at the lowest level of the energy ladder, "initial energy", and the ladder above it is "transition energy" (charcoal, coal, kerosene), "quality energy" (electricity, liquefied petroleum gas/natural gas, biogas). However, under the opportunities brought by carbon neutrality, biomass will likely appear in different forms in different application scenarios, and it is likely to achieve a grade leap on the ladder of energy varieties. Especially under the common needs of clean power and cogeneration in the future, biomass energy can not only help clean power generation and clean heating, but also have the opportunity to achieve negative carbon emissions. In the context of carbon neutrality, the stage for biomass to play a role will be wider.

Biomass energy has a unique role in the clean supply of electricity and heat and should not be simply compared with scenery

First, biomass energy is fundamentally different from wind and solar energy in nature, and therefore its role in the power system will be different. In the future, biomass energy is not simply seeking to contribute a high proportion of electricity generation in the entire power system, but to play a unique role in the system.

The intermittent characteristics of renewable energy will bring some challenges to the stability of the new power system based on wind and light. For example, if there is no wind for several days, or if it is persistently cloudy, or if it catches up with the winter dry season, the problem of system stability will be highlighted. The current electrochemical energy storage technology can only cope with hour-level peak cutting and valley filling, and the energy storage problem on a longer time scale has not yet found a zero-carbon solution that is mature in terms of economic and technical feasibility. Therefore, for the stability of the power system, it is necessary to retain a certain proportion of thermal power - in the context of current existing and foreseeable technical conditions, there is basically a consensus in all circles on this point. The further question, then, will be, what is the source of fuel for this part of the thermal power? If the starting point is a zero-carbon future scenario, possible options include coal power plus CCS/CCUS (carbon capture and storage/utilization), or replacing coal with green hydrogen, or replacing coal with biomass.

This is why the economic viability of biomass energy needs to be compared with the economic viability of technologies such as CCUS and the use of hydrogen energy for cross-season energy storage. The task of biomass energy is to solve the instability problem caused by wind and light power generation in the future new power system. At present, this problem is electrochemical energy storage, pumped storage can not be solved temporarily.

In addition to power generation, another unique role for biomass lies in heating. Heating is one of the most difficult problems to solve in the process of achieving carbon neutrality. It is directly related to people's livelihood, the energy demand is huge, must be stable and secure. In the context of carbon neutrality, how to solve the heating problem in the northern region in the future, the current discussion mainly involves two ways: one is to consider centralized heating, using renewable energy generated by heat pump to heat; The other is to preserve the existing heat network, so that a part of the thermal power needs to be retained.

At present, the first way faces several challenges: First, China's urban population density is very high, especially in winter, that is, photovoltaic power generation and hydropower are in the trough period, may need to increase a very large amount of installed capacity to ensure the power supply required for heating, which may make the power grid overwhelmed; Second, under the existing technical conditions, the city does not have enough land space to install centralized heat pump; Third, in this case, there is a risk that infrastructure such as heat grids will become a sunk asset in the future.

While we have high hopes for electrification, we are also supporting efforts in rural areas and small towns in the south and north. However, the author believes that based on China's national conditions, in large and medium-sized cities in the north where the population is concentrated, the second way is more feasible, that is, in the future, a part of the new power system needs thermal power, and this part of thermal power can also play the role of heating. In the process, biomass will have the opportunity to take advantage of its zero-carbon advantages in both electricity and heating.