Tesla's battery station saved Australia already $ 30 million

The world's largest rechargeable battery installed by Tesla Inc. in South Australia, already plays an important role both in the region’s energy sector and in its economy. According to the administration, Hornsdale Power Reserve (this is the official name of the battery) has reduced the cost of operating the network by about 90%.

The region in which the battery is installed receives energy mainly from alternative sources - these are solar batteries (there are not so many of them) and wind turbines. But there are days when the performance of these sources falls - for example, when there is no wind and overcast. In this case, it is necessary to turn on gas generators connected to steam turbines, and to produce the missing part of the energy.

In such periods, the cost of electricity in South Australia rises to $ 14,000 per megawatt. The Tesla battery, as it should be for the battery, accumulates energy when it is supplied to the network of the region in excess and gives it away in the days of “shortage”. Thus, it is not necessary to use gas generators, and the cost of operating the network, and accordingly the electricity itself falls.
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The battery is so efficient that it helped save about $ 1 million over just a few January days. However, then Tesla Company complained that the calculations with it were carried out incorrectly, because the power system does not take into account the rate of reverse discharge of the battery in the network of South Australia. As far as can be judged, the system has become a victim of its own effectiveness.

The administration of the region and the grid operator have already expressed their admiration for the work of this system. Now the battery took over about 55% of the functions of FCAS (Frequency Control Ancillary Services) and reduced the cost of operating the network by 90%, as mentioned above.

Among its other advantages, the battery responds quickly to abrupt changes in the electrical network: for example, on December 14, 2017 at 01 h 59 min for technical reasons the coal-fired power plant Loy Yang A 3 suddenly disconnected from the common network within milliseconds - 4 seconds faster than the standby frequency control and ancillary services generator (FCAS) in Queensland. At full capacity from 0 to 100 MW, the station goes beyond 140 milliseconds.

The speed of work is also needed in cases where other sources of energy are disconnected from the network due to an accident. This happened, for example, on December 18th. Then the 689 MW coal-fired power plant in New South Wales was cut off, which caused a shortage of power in the network. This shutdown did not entail any very negative consequences, as they covered the shortage with the help of reserve capacities at other enterprises. The frequency of the current was kept at 49.5 Hz. If the situation developed further, then a complete blackout could occur in a large area.

According to the calculations of officials, the battery capacity is about 2% of the conventional capacity of the entire network. At the same time, these 2% give 55% savings in operating costs. For four months, South Australia became the only region in the country where FCAS expenditures decreased for the indicated four months. The battery saved the administration of the region about $ 30 million.

According to Tesla, such significant savings were achieved due to the fact that during periods of "subsidence" in the production of energy gas generators are used much less than before. They run on fuel, the cost of which is very high, but the battery receives energy from wind power plants. The energy they produce is cheaper than “fuel”.

Currently, the system operates in two modes. The first, with a capacity of 30 MW / 90 MW · h, is used by the operator Neoen to sell electricity in the external market. The remaining energy is used by the state grid operator to equalize the voltage in it. The battery almost instantly turns on and off, and it is able to respond to price changes in the spot market. When prices are as high as possible, and the load on the network rises to the maximum rates - the battery turns on, giving away the previously accumulated low-cost electricity.

The company Mask built the battery in just three months. If Tesla would not have managed during this period, Australia would get the battery for free.