Solar energy + thermal system uses sunlight and heat to generate electricity.
Through a large-scale array of flat reflectors and parabolic reflectors, solar heat energy is reflected in a given small area, collecting solar heat energy.
The heat exchange device is then used to provide steam, which is combined with the traditional steam turbine generator process to generate electricity.
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Solar thermal power generation stores energy and molten salt heat storage is usually used.
During the day, solar heat is collected and stored, and at night, the remaining heat is used to generate electricity.
Therefore, photothermal power generation is the integration of power generation and energy storage, which is much more stable than photovoltaic panel power generation.
It can achieve thermal power output quality (coal power) and has great development prospects.
Solar energy storage technology uses PV panels to generate electrical energy. It is clean, renewable, noiseless, and pollution-free.
Photovoltaic energy storage systems can be used in distributed energy systems, microgrids, household electricity, and other fields.
They are one of the key directions for renewable energy development in the future.
Application scenarios:
Solar thermal storage or solar energy storage systems are widely used worldwide.
Here are some typical examples.
United States: California, in the United States, has built the world’s largest photothermal energy storage power generation project – Solar Park. This project uses trough collectors to convert solar energy into thermal energy. It stores heat through molten salt and releases it to generate electricity when needed.
United Arab Emirates: The 700-MW CSP project in the Dubai Maktoum Solar Park in the United Arab Emirates is currently the solar thermal storage project with the largest installed capacity, highest investment scale, and largest molten salt tank heat storage in the world.
It uses the world’s leading “tower + trough” concentrated solar thermal power generation technology, using molten salt to store a large amount of heat energy generated when the sun is abundant during the day and provide power at night or on cloudy days.
It can continuously and stably convert solar energy into electrical energy for 24 hours.
In addition, countries such as Australia, Chile, Morocco, and South Africa are also actively developing solar thermal systems. This is to cope with power demand and energy structure transformation.
In the future, with technological advancement and cost reduction, the global application prospects of photothermal energy storage power generation technology will be broader.
What does a solar thermal system include?
Concentrator: Concentrates sunlight on the collector to increase sunlight energy density.
Heat collector: absorbs sunlight and converts it into heat energy, heating the internal heat transfer medium (such as thermal oil or molten salt).
Heat absorber: further heats the heated heat transfer medium in the collector to a higher temperature for subsequent thermal energy storage and power generation.
Molten salt tank: stores molten salt as a heat transfer medium and thermal energy storage medium.
Heliostat: Reflects sunlight onto a concentrator to increase sunlight energy density.
These devices play different roles in the pv thermal energy storage system and jointly complete the process of photothermal energy storage.
It should be noted that different types of solar thermal energy storage projects may require unique equipment.
The specific configuration and specifications need to be selected based on the actual project situation.
By what technology do solar thermal systems generate electricity?
Trough thermal oil heat transfer to molten salt heat storage: This technology uses parabolic trough concentrators and collector tubes, and adopts dual-loop system technology of synthetic thermal oil, molten salt, etc as the working medium.
It is currently considered one of the most mature photothermal power generation technology routes, with a high degree of commercial verification.
Linear Fresnel: This technology uses linear Fresnel reflectors to focus sunlight on a heat transfer medium (such as water, thermal oil, or molten salt). The heating medium generates steam to drive a steam turbine to generate electricity.
Tower-type molten salt heat transfer: This technology is centered on a high tower, with heliostats arranged in a circle around the tower, emitting sunlight to the heat absorber of the high tower to heat the molten salt medium at the top of the tower, through the high-temperature molten salt. By circulating heated water, steam is generated to drive the turbine.
Dish type: This technology uses parabolic reflectors to focus sunlight onto a central heat absorber. The heating medium generates steam to drive a generator to generate electricity.
These technologies and processes have their characteristics and advantages in photothermal power generation. A specific technology and process must be selected based on the actual situation.
How do solar thermal systems work?
Solar energy collection: sunlight is focused through a solar collector (such as a parabolic reflector). This point is usually placed in the center of the collector, called the “focus”. Collectors convert sunlight into heat energy.
Thermal energy storage: Thermal energy is stored in a thermal storage system, usually using materials such as molten salt or concrete as the thermal storage medium. These media store thermal energy for long periods and release it when needed.
Thermal energy conversion: The thermal energy stored in the thermal storage system can be converted into electrical energy through a heat exchanger. This process is usually accomplished using steam turbines or Stirling engines.
Electrical energy storage and release: The converted electrical energy can be stored in batteries or other storage devices to be released when needed.
Solar thermal storage systems collect, store, and convert solar energy through collectors and thermal storage systems. This is done by converting it into electrical energy that can be stored and released.
Compared with solar energy storage systems, photothermal energy storage system has a higher energy density and a longer storage time. However, solar thermal system also requires a greater initial investment cost.
Algorithm for total power generation of a solar thermal storage system
Calculate the total power generation of 100,000 kilowatts of solar thermal (energy storage) + 900,000 kilowatts of photovoltaics:
First, we need to know what the power generation of solar thermal and photovoltaic is, and then add them together to get the total power generation.
Photothermal power generation (GWh_CSP) and photovoltaic power generation (GWh_PV) can be expressed by the following mathematical formulas:
GWh_CSP = 100,000 × photothermal conversion efficiency
GWh_PV = 900,000 × solar conversion efficiency
Total power generation = GWh_CSP + GWh_PV
Here, we assume that both the photothermal conversion efficiency and the photovoltaic conversion efficiency are 0.3 (this is a commonly assumed value, the actual value may be different).
Substitute the values in the equation to find the answer.
The calculation results are: the annual power generation of 100,000 kilowatts of solar thermal (energy storage) is 3 GWh, and the annual power generation of 900,000 kilowatts of solar is 27 GWh.
Therefore, the total power generation capacity of 100,000 kilowatts of solar thermal (energy storage) + 900,000 kilowatts of photovoltaics is 30 GWh.
Why do solar thermal storage projects require evaporative crystallized materials?
First of all, the evaporation and crystallization system is one of the critical links for thermal energy storage and release in photothermal energy storage projects.
Solar thermal storage systems absorb solar energy and convert it into thermal energy for storage. They then release stored thermal energy to generate electricity when needed.
The evaporative crystallization system can store this stored thermal energy in the form of crystallized salts, etc., and release it through the evaporative crystallization process when needed for power generation.
Secondly, evaporation and crystallization systems can provide reliable energy storage media. The energy storage medium in a photothermal energy storage system needs characteristics such as efficiency, safety, and reliability.
Substances such as crystallized salts in evaporative crystallization systems can serve as reliable energy storage media.
In the process of storing and releasing thermal energy, stable performance, and high energy conversion efficiency can be maintained.
In addition, evaporative crystallization systems can also improve photothermal energy storage efficiency and reliability. During the evaporation and crystallization process, impurities and moisture can be removed through the treatment and separation of crystallized salts.
The purity and quality of the energy storage medium can be enhanced. This improves energy conversion efficiency and reliability of photothermal energy storage systems and reduces operation and maintenance costs.
In a solar thermal system, a solar collector converts sunlight energy into thermal energy and heats the working fluid (such as water, oil, or salt) in the collector.
These working fluids absorb thermal energy are heated to a high temperature, and then transported to a thermal system for storage.
The stored thermal energy can be released when needed through devices such as heat exchangers for applications such as power generation or heating.
In an evaporative crystallization system, stored thermal energy is used to heat and evaporate the crystallization medium (such as salts), so that moisture and impurities are removed, leaving concentrated crystals.
These concentrated crystals can be further processed and separated to obtain high-quality energy storage media.
Therefore, evaporated and crystallized substances come from the working fluid and crystallization medium in solar collectors and heat storage systems.
These substances store and release thermal energy in photothermal energy storage systems.
They obtain high-quality energy storage media through evaporation and crystallization to improve the system’s efficiency and reliability.
What is the value of investing in a solar thermal storage project?
Power peak shaving: Solar thermal energy storage projects can be used as power peak shaving power sources to release stored thermal energy for power generation during peak power demand periods, balance the grid load, and improve the power system stability.
Energy supply: Solar thermal energy storage projects can be used as a supplementary means of energy supply to meet energy needs by releasing stored thermal energy when the power supply is limited or interrupted.
New energy grid connection: Solar thermal energy storage projects can be used as a support method for new energy grid connections.
When power generation from diversified energy sources such as wind energy and solar energy fluctuates greatly, stored thermal energy can be released to balance the grid load.
This will improve the grid connection of upcoming energy sources. Rate and utilization.
Generally speaking, solar thermal energy storage projects have potential commercial value and market prospects.
However, varying investment and returns, as well as market prospects, need to be analyzed and evaluated based on regions and specific projects.
Market prospects vary by region and by specific projects.
Does solar thermal energy storage require manual maintenance?
Solar thermal system projects usually include equipment maintenance and repair, thermal energy storage and release operations, power conversion, transmission and distribution, etc.
These operations require professional technical personnel and managers to ensure the project’s normal operation and safety.
In addition, manual operations also require monitoring and managing the project. This includes handling possible problems and failures promptly and taking corresponding measures to ensure the project’s stability and reliability.
Modern solar thermal energy storage projects usually use automation and intelligent technologies to improve efficiency and reliability. Manual operation is still essential.
Technical personnel and managers need to supervise and manage according to the actual situation of the project to ensure its safety and stability.
At the same time, manual operations can also be flexibly adjusted and optimized according to actual needs to meet the different needs of the project.
To sum up, solar thermal storage projects require manual operation. However, the specific operation content and frequency need to be evaluated and managed based on the actual project situation.
Which factors influence solar thermal system purchases?
Funding issues: CSP energy storage projects require a lot of capital investment, including equipment purchase, construction, commissioning, and trial operation. Some projects may face stagnation or slow progress due to funding issues.
Technical difficulty: Photothermal energy storage technology is relatively complex and requires advanced technology and equipment support.
At present, photothermal energy storage is not mature enough, and some technical bottlenecks and problems require further research and development.
Geographic and climatic conditions: The development and construction of solar thermal energy storage projects are restricted by geographical and climatic conditions.
Some areas have limited lighting resources or harsh climate conditions, which hinder the construction and operation of photothermal energy storage projects.
Policy and market environment: Policy and market environment are also significant factors restricting photothermal energy storage development.
Some countries and regions lack clear policies and plans for solar thermal energy storage. They have low market acceptance, which will also affect solar thermal energy storage development and construction.
Industrial Chain and Supporting Facilities: The development and construction of solar thermal energy storage projects requires a complete industrial chain and supporting facilities, including equipment manufacturing, installation, commissioning, operation, and maintenance.
The photothermal energy storage industry chain in some areas is not complete enough, which restricts project development and construction.
How long does a solar thermal system last?
Generally, the service life of solar thermal system for power generation is about 30 years.
Specifically, the full life cycle (30 years) of a 110MW tower solar thermal power storage station with 17.5 hours of energy storage.
The climate change indicator per kWh of net electricity generation is 9.8 gCO2 equivalent/kWh.
Please note that service life may be affected by a variety of factors, such as equipment quality, operation and maintenance, etc., so the specific service life will vary depending on the actual situation.
What are the solar thermal system companies?
Shouhang High-tech: Mainly engaged in research and development, design, manufacturing, equipment supply, construction, operation, and maintenance in the fields of photothermal power generation.
Photothermal energy storage + multi-energy complementation, hydrogen energy utilization, power station air cooling, waste heat power generation, clean heating, seawater desalination, etc., a high-tech enterprise providing project investment and general contracting services.
It is a comprehensive solution and core equipment supplier for photothermal power plants and energy storage technology. In addition, it is a supplier of core equipment for clean energy and next-generation power systems.
3D Chemistry: It has developed the QDB series of sulfur-tolerant shift catalysts (mainly used in the coal chemical industry) with comprehensive performance at the international leading level, and has the domestic leading “50,000 tons/year rare earth rubber production process and catalyst preparation technology”.
The company can provide users with products with more than 30 specifications, including catalysts, hydrolysis agents, desulfurizers, and detoxification agents.
Shanghai Electric: The leading industry focuses on the three major sectors of energy equipment, industrial equipment, and integrated services.
Forming a relatively complete specialized automation and industrial equipment system, providing full life cycle services for many high-end equipment, and leading the development direction of multi-energy complementation and energy interconnection.
The above information is for reference only. If necessary, you can contact us for a consultation.
