Energy storage + port operation! Cost reduction of 30%!

Recently, the first batch of floating photovoltaic modules for the Hollandse Kust Noord offshore wind farm in the Netherlands has arrived at the Port of Amsterdam, and it is planned to be assembled and installed in the wind farm in 2025.

It is understood that the floating solar energy system is the world's first offshore solar photovoltaic power generation system that has been verified in high waves, and can withstand 13-meter-high waves and 110 km/h hurricanes. At the same time, it is understood that the HKN project integrates a variety of low-carbon technologies and plans to combine floating photovoltaic equipment and short-term energy storage batteries.

To put it bluntly, this is a super hybrid of "offshore wind power + offshore photovoltaic + battery energy storage + green hydrogen production".

In fact, this is not the first port to use energy storage.

In April 2021, the first domestic shore power storage integrated system was completed and put into operation in Lianyungang, Jiangsu.

This year, the first low-carbon terminal demonstration project in Zhejiang Province, the State Grid Ningbo Zhoushan Port Meishan wind, light and storage integrated project, was also successfully put into operation.

Cold knowledge: What is shore power?

To understand the energy storage + port model, we must first know the term "port shore power".

You should know that ports are large electricity users. As the scale of ports continues to expand, their consumption of electricity has also received more and more attention. The main power load of ports is concentrated on high-power, long-duration equipment.

Port shore power refers to a green energy consumption model in which port facilities and berthed ships use electricity as the main energy source. It is mainly divided into two forms: port oil-to-electricity and ship shore power. Among them, port oil-to-electricity is to transform the main large-scale loading and unloading mechanical equipment of the port, such as shore cranes and yard gantry cranes, which were originally powered by diesel engines, into electric mechanical equipment powered by electricity. Ship shore power is to stop using the fuel generator on the ship when the ship is docked at the terminal and use the power supply system provided by the terminal to power the ship.

We are mainly talking about ship shore power here.

The ship shore power system is mainly composed of a shore-based power supply system, a ship-to-shore connection system, and a ship-borne power receiving system. In simple terms, the shore power access process is that the high-voltage power supply on the shore is converted into low-voltage power by a transformer, and then connected to the docked ship through a series of equipment for use. With the voltage of 1KV as the dividing line, the shore power system is divided into high-voltage shore power system and low-voltage shore power system, and the voltage levels adopted by different countries and regions are different.

With the proposal of the "dual carbon" goal, the promotion of ship shore power is a major trend. However, with the large-scale application of ship shore power, problems also arise.

The increasing power electronics of port power equipment and the large number of impact loads pose a severe challenge to the voltage quality of the distribution network, resulting in frequent voltage fluctuations and flashes, and the efficiency of the power supply and distribution network is greatly reduced. Especially when fuel prices are low, the economic advantages of shore power are not obvious, and its development is therefore subject to many restrictions.

Energy storage comes in handy at this time.

Simply put, it is like a "giant power bank", which stores electricity in batteries during low electricity price periods and releases it when shore power demand peaks. This technology not only effectively alleviates the peak-valley contradiction of the power grid and realizes the "peak shaving and valley filling" of electricity, but also further reduces the cost of ships using shore power, provides strong support for the widespread application of shore power, and promotes more efficient and environmentally friendly use of energy in ports.

What are the advantages of energy storage + port?

Specifically, the advantages of energy storage + port are still very prominent.

1. Improve power quality and power supply reliability

Smooth load fluctuations: A large number of power-using equipment in ports are electronic, and there are impact loads, which will have a serious impact on the quality of distribution network voltage, resulting in voltage fluctuations and flickering in the power grid. The energy storage system can smooth peak loads such as shore power and voltage fluctuations, directly filter the "noise" of the power grid, and improve the power quality of the port power grid.

Backup power supply: The energy storage system can be used as a backup power supply to provide reliable protection for the port when there is insufficient power supply or power failure in the port power supply network. This avoids the failure of ship-side equipment caused by sudden power failure and improves the power supply reliability of the shore-based power supply system.

2. Promote the construction of green ports

During the operation of ships at the port, the auxiliary generators on the ship need to be started to generate electricity to provide the necessary power, which will generate a large amount of harmful substances.

Someone once calculated that the PM2.5 pollutants emitted by a medium-sized container ship in one day are equivalent to the daily emissions of 500,000 National IV trucks, accounting for 70% of the pollutant emissions during the entire ship operation process, causing port pollution.

Using shore power storage system to provide electricity can replace the ship's own auxiliary generator, thereby reducing carbon emissions during the ship's berth and improving the air quality of the port and the city where it is located.

According to data, my country's port ship auxiliary power generation consumes up to 700,000 tons of fuel oil annually, and auxiliary power generation accounts for 40% to 70% of the total carbon emissions of the port, and the specific proportion varies depending on the type of cargo. Imagine that if all shore power is used to replace auxiliary fuel power generation, the environmental pollution of the port will be significantly improved. It is estimated that in the annual emissions, nitrogen oxides will be reduced by at least 47,665 tons, sulfur dioxide will be reduced by at least 37,800 tons, and inhalable particulate matter PM10 will be reduced by at least 2,214 tons.

More importantly, energy storage + port has promoted the consumption of new energy to a certain extent. As mentioned at the beginning, the "wind + light + energy storage" power generation system of the Hollandse Kust Noord offshore wind farm can make full use of the geographical advantages of the port, use wind and solar energy on the seashore to generate electricity, and supply power to the load in the port area. At the same time, the energy storage system can effectively smooth out power fluctuations of solar power generation and wind power generation, and improve the grid's ability to absorb new energy.

3. Realize economic benefits

The industry has made such a calculation. Taking a standard cargo ship that normally docks at the port as an example, there are generally three 880-kilowatt auxiliary engines on board. After docking at the port, 1 to 2 of them will be activated. The auxiliary engines of cargo ships docked at Lianyungang Port are used for about 2,000 hours throughout the year, consuming about 780 tons of heavy oil, light oil and other fuels, and requiring expenditures of about 3.96 million yuan.

The use of shore power can greatly save energy costs.

According to estimates, the unit price of shore power use at 9 berths in Lianyungang Port is 0.9 yuan/kWh. After the shore power energy storage integrated system is put into operation, the unit price of shore power use will drop to 0.7 yuan/kWh. Compared with the use of fuel oil, the operating cost of ships during the berth can be reduced by about 30%.

Specifically, port electricity is charged by peak-valley price difference. During the day, it is the peak electricity price, and load operations are mostly during this period; at night, it is the valley electricity price, and the load operation time is relatively short. The energy storage system can store electricity when the electricity price is low, and release electricity for port use when the electricity price is high, realizing the transfer of peak and valley electricity, saving a lot of electricity costs for the port.

At the same time, the main power load of the port is concentrated on high-power and long-time working equipment, which will generate a lot of electricity during braking. Energy storage technology can recover this braking energy and store it for reuse, so as to achieve the purpose of energy saving and improving power quality.