Cleantech company Themo developed a unique smart thermostat technology that allows electrically heated premises to earn money by participating in balancing the grid

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The smart thermostat technology of the Estonian-Finnish cleantech company Themo has passed the requirements for Fingrid's Frequency Containment Reserve in Finland. This means that the frequency of Finland's national electricity grid can in the future be balanced quickly and easily through the heating systems of all Finnish electrically heated households and other residential and accommodation spaces. 

Themo's smart thermostats save money for their users by optimizing electricity consumption while considering the current market price. In addition, the owners will now be compensated for the utilization of thermostats in the reserve market. Themo also secured a growth funding of 1.3 million euros for product development.

Themo's core innovation is an efficient electricity optimization algorithm on which the company's smart thermostats are based. In addition to many other parameters such as time of day and weather forecast, the algorithm considers fluctuations in the price of electricity on the stock exchange when optimizing electric heating. 

Musta Themo Älytermostaatti puisella pöydällä

Themo thermostats can now also be used to balance the frequency of Fingrid's grid. The reserve market operated by Fingrid is used to adjust the grid to balance electricity consumption and production. Themo's technology can control many relatively low-power, standard electric heaters with a fast response time.

"We have successfully verified the operation of 1 MW of power mass under test conditions organized by Fingrid. To pass Fingrid's FCR-D market requirements, the reserve market supplier must be able to detect the frequency deviation and make the necessary adjustment itself within 7.5 seconds. With our sophisticated cloud solution, aggregation and adjustment of devices is possible in seconds."

Madis Uuemaa, CEO and technology developer at Themo


Aggregated power from 20,000 smart thermostats balances the frequency of the grid 

Frequency Containment Reserve for Normal Operation (FCR-N) and Frequency Containment Reserve for Disturbances (FCR-D) are active power reserves that are automatically controlled based on the frequency deviation. The Frequency Containment Reserve for Disturbances (FCR-D), the control test which Themo smart thermostats have now passed, maintains a frequency of at least 49.5 Hz or up to 50.5 Hz when the frequency deviates from the standard range. At equilibrium, the frequency is 50.0 Hz.

“In practice, this means that when a frequency deviation is detected, the algorithm automatically switches on all Themo smart thermostats for a short period of time, for instance, 20 seconds. Switching on does not affect the heating of the home or heating costs, but with 20,000 electric heaters in the Finnish market alone, aggregated power has a significant balancing effect on the frequency. In addition, Fingrid will pay compensation based on marginal pricing," says Uuemaa.


Themo's b2b customers involved in the reserve market

Intelligent and rapidly adjustable electrical innovations like Themo are key to the transition from fossil fuels to more sustainable energy solutions. New energy solutions such as solar and wind are more volatile for the grid. To balance the frequency deviations of the grid, reserves are needed and Fingrid will purchase them from the market it operates. Such reserves are for example power plants, consumption targets, and energy storage facilities that change their output as needed. 

"It is a great achievement and socially important that we can use the large reserves of existing electric heaters to balance the grid. In the past, balancing was done mainly by fossil power plants. The technology developed by Themo is an important part of future smart electricity grids."

Joonas Rantala,  Sales Director at Themo


Themo's b2b customers, such as Sato, Y-Säätiö, Asuntosäätiö, rental housing companies owned by the largest Finnish cities, Holiday Club resorts, and some other companies offering rental housing and other types of accommodation or care services participated in the approved test. In the future, Themo's b2c customers will also be able to participate in the reserve market.

Themo manages around 10 MW under its current customer base. The aim is to manage 60 MW by the end of 2026.


EUR 1.3 million growth funding for product development

In addition to passing Fingrid's reserve market regulation test, Themo also secured EUR 1.3 million in growth funding for product development. This funding will strengthen Themo's position in the market and enable it to invest increasingly in smart energy solutions. The company's long-term goal is to secure emission-free and affordable electricity for everyone. With smart thermostats, customers can save up to 50% of electricity compared to manual thermostats. For large rental property operators or hotels, financial savings can amount to tens of thousands of euros.



Pictured from left: Joonas Rantala, Sales Director of Themo, Madis Uuemaa, CEO and Markus Perkkiö, CFO.

The lead investor in the funding round is Sunly, an Estonian company investing in renewable energy and modern technology. Sunly has already participated in Themo's previous funding rounds. The second largest investor is Finnish Indie Investments, owned by Heikki Nakari. Other Finnish angel investors such as Henry Nilert, Ali Omar and Pekka Ylitalo are also involved.

For more information:

Madis Uuemaa, CEO 
+372 5373 7004

Joonas Rantala, Sales Director 
+358 40 827 1962

Themo is an Estonian-Finnish cleantech company founded in 2014. Themo consists of the parent company Smart Load Solutions OÜ and its wholly owned Finnish subsidiary Themo Nordic Oy. The technology developed by Themo is an important part of the smarter electricity grid of the future. The company's long-term mission is to enable clean and affordable electricity for all.

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