All kinds of non-fossil power generation are pollution-free, but they are all greatly affected by natural phenomena, such as Day and night, wind, dry season, etc.
Photoelectricity has day and night problems, wind power has weather problems, hydropower has dry season problems, and waves are affected. The impact of sea conditions is great, the tidal gap is too small, and the development of new energy is in full swing, but the problem is still not small. The biggest problem is intermittent. The national interconnected high-power smart grid can solve some of the problems, but it can’t solve it essentially, and the problem of peak power consumption in China is increasing.
It is said that the electricity consumption in the United States is 30%industrial and 70%civil (residential and commercial), while China is just the other way round, 30%civil , 70%industry. This of course reflects the reality that China is the absolute largest manufacturing country in the world, but this ratio will gradually be Americanized, if it does not reach the point where it is just reversed. Southern heating and northern air-conditioning are problems that can only be solved by electricity, and other solutions have various efficiency problems. The overnight commercial use of electricity, including lighting and air conditioning, will also increase. Another potential big consumer of electricity is urban agriculture.
Urban vegetable gardens can solve the problem of arable land and fresh fruits and vegetables, but they needElectricity
RoofVegetable gardens, underground vegetable gardens, indoor vertical vegetable gardens and other new vegetable gardens may become important sources of urban food in the future. Rooftop vegetable gardens are okay. Electricity is mainly used for irrigation. Artificial lighting is required for underground vegetable gardens. Indoor vertical vegetable gardens also need to add temperature control and regular rotation and replacement of cultivation racks. These all need electricity, and there can be no intermittent or counter-cyclical.
Using fossil fuels as a source of peak power is the easiest solution, but carbon emissions are an unavoidable problem. Nuclear power not only has the problem of disposing of spent fuel, it is also not suitable for rapid load increase and decrease, and it is not suitable for peak shaving power. Pumping energy storage needs to be in Building a reservoir on the top of the mountain makes it difficult to avoid potential safety hazards, especially when peak shaving is most needed.Power stations densely populated areas. Lead-acid batteries have low efficiency and high solid pollution, making them unfeasible as a large-scale peak-shaving power station. The safety of the concentrated use of high-power lithium batteries is a big problem, and there is also a problem of solid pollution treatment. It still needs professional, efficient, safe, and easy-to-spread new technology peak shaving power technology.
Use excess electricity to produce hydrogen, store hydrogen (gas or liquid) as energy storage, and use hydrogen fuel cells when needed Or directly burn to generate electricity, which is another way of thinking. However, the cost of hydrogen production by electricity is still very high and the efficiency is low. Hydrogen storage is a difficult problem to solve. It is better to say that the safety of long-distance transportation is a big problem. Hydrogen production also requires a water source, which is another restriction. Using seawater to produce hydrogen is not afraid of lack of water, but the hydrochloric acid and caustic soda produced after electrolysis are not easy to handle. The industrial consumption is not that large, and direct discharge is absolutely impossible. The accumulation of time is even more harmful.
Large-scale mines are like artificial lakes dug deep underground, and the lower storage pool used for pumping water and energy storage is just right
After the abandoned underground tunnel is properly reinforced and leak-proof, it can also be used as an underground storage pool
Pumped water storage The technology is simple and mature, but geography and security are a problem. However, if conditions permit and geographical conditions permit, underground tunnels, quarry pits, open-pit coal mines, etc. can be used. Natural Rock caves, karst caves can also be considered. Meticulous geological surveys may be required, as well as proper reinforcement and sealing of the hole ratio. However, once completed, such underground pumped water energy storage can use readily available and reliable technology to pump water up at the peak of new energy power generation and fill it into an upper storage tank on the ground. When peak shaving or trough is needed to supplement electricity, put the water back underground and generate electricity in the process .
Pumped water energy storage is the use of upper and lower pools to pump water back and forth to store energy and discharge water to generate electricity
The CSP station can remove excess high temperature Molten salt is stored underground and pumped up at night for power generation
Molten salt can be used for solar thermal power generation. This can also be used to pour high-temperature molten salt into underground caverns for heat preservation during the peak of power generation, and pump it to generate electricity when peak shaving and trough supplementation are required. This not only requires a suitable underground rock cave, but also requires insulation and leakage prevention on the wall of the cave. The requirement is higher than that of underground pumped water storage, but it is directly integrated with the CSP station to generate electricity day and night.
In addition, you need a little bit of crookedness.
borrowing cable carclass="candidate-entity-word" data-gid="2011328" qid="6595514017253463300"> The idea of span> is to use a cable car to load heavy objects, move it to the mountain when storing energy, and load it into the cable car when generating electricity and use gravity to pull power. But as energy storage and power generation, it may be steeper and more efficient
Pulling and releasing heavy vehicles back and forth on the sloped track is Another way
The mountain top cable car is an idea, but the other way around. When storing energy, the heavy objects are pulled through the cable car to the stacking yard on the top of the mountain; when generating electricity, the heavy objects are put into the cable car one by one and pulled down by gravity to drive the generator to generate electricity. This can be achieved only in general mountainous areas. Of course, this is different from the manned cable car. There are no comfort and sightseeing issues. The steeper the mountain, the higher the efficiency of energy storage and power generation. In the west, where photovoltaics are developed, there are also many mountains. Building such a cable car power station on a desolate mountain has little impact on the ecology and landscape, but it can solve the problem of energy storage on the spot.
Even on the relatively flat southeast coast, there is enough The hills can build such a cable car power station. It is much easier to solve the safety problem with the barrier ditch, the barrier dam, etc. than the high mountain reservoir.
The same cable car power station can be realized in deep water. It can use heavy objects, but needs to overcome the reduction in efficiency caused by buoyancy; it can also be used Floating body. For example, during the energy storage period, the hollow sphere is filled with light oil and pulled to the bottom with electricity; during the power generation period, it floats to drive power generation. Or it is more efficient. Gravity sinks naturally during the energy storage period, and light oil is filled underwater to save electricity. Floating power generation is the same. This can be used for offshore or deep lakes. The difference in water temperature between deep water and shallow water can also be used to further increase the buoyancy effect.
But it’s more straightforward to use shafts, and the UK has already started to experiment.
The typical configuration is a deep well-weight hammer system. The electric winch at the well head is a reversible motor. Energy (in the form of potential energy); when the heavy hammer is released, the heavy hammer pulls the motor to generate electricity. You can specify several generations and several idlings as needed, change the energy release speed and the amount of power generation, and make up for the instantaneous peak power generation and the durable trough. Adjust between electricity.
according to the simplest calculation, according to Canada typical annual electricity consumption of independent households 8000kw-hour Electricity consumption is used as the upper limit reference, ignoring seasonal differences. The daily 12-hour non-sunlight trough is calculated, of which 4 hours is the peak power consumption, and the power consumption is 3 times the trough, which is converted into peak power consumption of about 2 kilowatts and trough power consumption of about 2 kilowatts. 0.7 kilowatts, and it is assumed that electricity consumption during the day is equivalent to the low valley at night. Assuming that the weight of the heavy hammer is 500 tons, the well is 800 meters deep, the energy storage is released without loss, the peak power generation is 200 kilowatts, which can cover 100 households, and the peak power generation is 5.4 hours. According to the 1:3 segmented power generation, it can be extended to 9.8 hours. It can generally cover the trough period.
But the 800-meter deep well is not everywhere, and the coverage of 100 households is not too large. In fact, if the loss of the system is included, there is a big discount. If the depth of the well can be reduced, such as 150 meters, it will be much easier to achieve. Even without drilling a deep well, the center tube of high-rise can be used to solve energy storage and low-valley recharge on site The problem.
The problem is that the weight of the hammer needs to be greatly increased at the same time. For 100 households, it needs to be increased to 2650 tons to restore the same power generation time, and the 150-meter high-rise building is far more than 100 households. Even if the electricity consumption of the actual households in the high-rise buildings in China is not as good as that of the Canadian independent houses as a reference, the actual The weight of the heavy hammer that needs to be increased is greater. But such a heavy hammer is not easy to handle, and it is even more inappropriate to put it on the top of a tall building.
But the safety problem of underground shafts is easier to solve. To increase the discharge time, it may be necessary for the shaft to be used repeatedly in one discharge cycle. The cable car concept can be used again. For example, every time you land to a low point, push an iron heavy hammer (for example, an iron heavy ball in a gondola), guide it to the parking lot, hoist the empty cable car up, and push the next iron heavy ball It sags again to release the energy storage, so that it goes round and round, which can greatly extend the discharge time. 100 25-ton iron balls are much easier to handle than a 2500-ton heavy hammer.
The intermittent problem of discharge can be solved by the power grid. Many vertical shaft energy storage power stations in the region are like four-cylinder and eight-cylinder engines. Flattening the crests and troughs can also be cut by supercapacitors to fill the troughs. At the head and bottom of the well, the same stacking yard as the bowling lane is needed to push the iron heavy balls out and take them back.
You don’t need iron balls, you can use water. You need a pool at the head and bottom of the well. If the water in the pool at the bottom of the well is pumped The wellhead also reduces the lifting power and wear of the electric winch, although the energy consumption during the energy storage stage is not reduced. The weight of water is 1 and iron is 7.9. The volume of the”water hammer” of the same weight needs to be much larger, but the actual limit cannot be too large. Fortunately, it can be used frequently and repeatedly to make up. The total power generation capacity. On the other hand, the pool does not need to be very large, in fact it weighs quite a bit. For example, a standard swimming pool of 50x21x1.8 meters can hold 1890 tons of water. Appropriate enlargement can greatly increase the water storage capacity, but a pool of this size is not technically difficult. This can also be used to maintain local power consumption with the fluctuating peak power of the external grid during the non-sunlight or windless season. As soon as there is available surplus power, water is pumped from the bottom of the well to the well head to maintain the long-term continuous operation of the shaft power station.
According to British calculations, the electricity cost of such an energy storage power station is half of that of lithium batteries, with a lifespan of up to 50 years, and the equipment is regularly updated There is actually no life limit, even if it is scrapped, the post-processing is much simpler. As long as the geological conditions are right, it is not a big problem for the shaft power station to bloom everywhere, and there is no pollution.
The lifting and lowering of cargo by the crane is not about energy storage, but a good way to save energy
Using low-peak power to make ice and peak melting to release cold is another peak shaving method
but compressed air Energy storage efficiency is too low
There are some non-professional energy storage and energy recovery technologies that are also worth considering. For example, the cranes of wharves and railway freight yards use electricity when they are hoisted, and electricity can be recovered when they are put down. This cannot be used as an energy storage power station, but a way to save energy. Another example is high-rise air conditioners. Ice is made during the day when there is an excess of electricity and stored in the cold storage of high-rise buildings. The circulating air is cooled during the peak cooling peak at dusk. This is also the way to release energy.
Once the energy storage problem is solved, new energy will become even more powerful. With nuclear power, China’s energy bottleneck becomes history.