VEO’s hybrid system revolutionizes the life expectancy of hydropower plants

A new solution developed for VEO’s hydropower automation portfolio will save turbines from mechanical wear when using frequency regulation. Based on VEO’s own hybrid governor and electricity storage system, the hybrid solution will enable hydropower plants that are already participating in the frequency regulation market to meet the tightening demands placed on frequency regulation, decrease mechanical wear on machinery and open opportunities for plants that are not presently suited for the frequency regulation market. Thanks to VEO’s solution, small-scale hydropower plants can now become valuable assets in situations where the power distribution network is malfunctioning and isolated grids are needed.

The idea to utilize electricity storage in turbine regulation started to take shape in Jukka Kelloniemi’s head in 2018. Kelloniemi, working as Team Leader in VEO’s hydropower automation team, had together with clients discovered that there was a returning worry in the field of hydropower: frequency regulation wears out the turbine and its mechanical regulation devices due to constant mechanical movement.

In Kelloniemi’s opinion, the situation called for an innovative system whereby mechanical regulation would be replaced by a battery of some sort; but the solutions must not be too costly. Hence, in autumn 2022, as a result of almost four years of research and development, VEO is now about to implement its solution, based on the hybrid governor (eHPG), by putting the new technology into practice at two hydropower plants (VEO’s previous press release).

The unique software of VEO’s digital hybrid governor enables turbine regulation either with or without an electricity storage solution. Since the purpose of the electricity storage is to aid the turbine in power generation, the storage does not have to be on the MW-scale. If the need is merely to support the turbine in frequency regulation, acquiring a small-scale electricity storage solution and grid connection technology will not necessarily require a sizeable investment.

“Numerical data and results from the actual execution in real hydropower plants will show us exactly what is the extent of the decrease in mechanical movement and direction turns affecting the regulation devices. According to the simulation model, there will be a significant decline, especially when the new regulations come into force”, Kelloniemi says.

With support from VEO’s hydropower client

The idea that started from Kelloniemi’s client contacts started to evolve as Kelloniemi had discussions with those responsible for frequency regulation matters in Finlands main electricity transmission system (Fingrid). He needed to know exactly what type of power producing processes are permitted.

“VEO saw the value in developing new solutions for future hydropower. After all, we already had a client from the beginning, Hydropower Manager Jari Kottonen from Helen Oy, who was interested in the idea. It takes an open mind and much courage from a client to start testing something that does not have a single reference yet”, says Kelloniemi respectfully when reflecting on the elements that enabled the product development.

Early in the process, Kelloniemi was allowed to test his idea in a client’s object – with two similar turbines. As the turbines were commanded to regulate frequency, one with a normal turbine governor and the other with a governor equipped with an add-on simulating Kelloniemi’s idea, the results measured were promising enough to convince both Kelloniemi and VEO’s client to continue development.

Also future demands from the European Network of Transmission System Operators for Electricity (Entso-E) were tested with the hybrid governor. This was conducted by simulating several variations on successful frequency regulation, which in turn allowed Kelloniemi to optimize the size of the electricity storage. To enable these tests, a simulator was developed to imitate the Kaplan turbine and to study power changes in connection to fast regulation.

“The results from the simulations have also encouraged our other clients to trust this system and its ability to bring significant added value to hydropower plants”, Kelloniemi explains.

VEO has been contracted to deliver VEO’s hybrid governor-solution to Helen Oy’s Mankala hydropower plant in spring 2023. Also Kemijoki Oy is about to take VEO’s hybrid system into use in connection to its on-going refurbishment of its Kurkiaska hydropower plant (Kemijoki Oy’s press release).

Frequency regulation products now and in the future  

With VEO’s hybrid governor, interconnected electricity storage can, besides the Frequency Containment Reserve (FCR) production of the turbine, even produce another reserve, a so-called Fast Frequency Reserve (FFR).

While producing the FCR-reserve, the hybrid governor keeps the charge level of the electricity storage constant so that reloading the storage does not add any stress to the grid. “This will certainly be positive news for the people responsible for the main grid as the solution will not add any stress or power load to the grid while it is recuperating from a frequency change”, Kelloniemi believes.

Containing the charge level of electricity storage is also important when considering the lifecycle management of the battery material.

Supply of local grid in island mode

Kelloniemi envisions that hydropower plants may regain a significant role locally even with a relatively small hybrid solution. In a case where the power grid is malfunctioning, a power plant equipped with VEO’s hybrid solution could restore power in an isolated part of the network with a so-called ‘black start’ process and thus secure power supply, e.g., to a particular socially essential object.

“In Finland, we have a great number of small-scale hydropower plants (capacity under 10 MW), and their significance to the electricity transmission system has been diminished. But with the hybrid system they may turn out to be real life-savers one day”, imagines Kelloniemi.

In Kelloniemi’s opinion, the hybrid system has considerable environmental benefits as it prolongs the lifespan of the turbine and regulation devices. However, he believes that it is important to keep in mind the big picture of green transmission. The increase of weather dependent energy sources such as wind and solar power often causes more frequency deviations, which means that hydropower plants have an increasingly important role in compensating them. VEO’s hybrid solution will allow a larger number of hydropower plants to contribute to this by participating in the frequency regulation market.

“The results from the simulations have also encouraged our other clients to trust this system and its ability to bring significant added value to hydropower plants.”

 

Jukka Kelloniemi, Team Lead,  Hydropower automation, VEO.