How Thunor and Qilowatt IT Help Optimize Energy Costs

In today’s rapidly changing world, managing energy consumption is becoming increasingly important, both for financial savings and for adopting an environmentally friendly lifestyle. In this post, we will discuss how the Estonian companies Thunor Solutions and Qilowatt IT help make your home’s energy consumption not only more efficient but also more sustainable and eco-friendly.

An energy storage system allows you to store both self-produced energy and energy taken from the power grid, thereby shifting the consumption curve away from peak hours. The inverter control unit adds "intelligence" for monitoring electricity market prices and managing major consumers, and it provides the opportunity to participate in the flexible electricity market.

Energy Storage Systems

When setting up a solar park, it is sensible to also acquire a battery bank, which maximizes the use of renewable energy in the household. We have written in more detail about the benefits of battery banks in our previous blog post.

In short, the battery allows you to store self-produced solar energy or charge the battery from the grid, thus shifting the household consumption curve. An important added value of the battery bank is that it can keep critical consumers operational during power outages.

The risk of power outages is high during the autumn-winter period, especially in sparsely populated areas where thousands of households in Estonia may be without electricity for shorter or longer periods. Storing energy reserves for outages allows the battery to keep critical consumers running. For one household, this might be a freezer and lighting, while for another, it could be a water pump or other essential equipment that ensures daily life continues.

Savings on Energy Costs Based on Market Prices

To utilize the energy produced by the solar park and manage the battery bank, an inverter is necessary. We have previously written about inverters, and you can read more about them here if you wish.

Thunor's clients often choose the Deye multifunctional hybrid inverter, which serves as an inverter, solar charger, and battery charger. Most inverters do not track market prices, but they can be manually configured to perform certain operations at specific times (e.g., storing energy from the grid, selling energy back to the grid, and determining when to use only stored energy in the household). Since market prices fluctuate daily, adjusting the inverter settings according to the market price can be quite cumbersome.

Qilowatt IT has developed an inverter and battery management solution called Modbus R2, which allows the inverter’s operation to be controlled based on electricity market prices. This small, smart device, which operates over a Wi-Fi network, obtains the most important information from the inverter regarding the produced energy and its storage in batteries. Modbus R2 instructs the inverter to stop selling electricity back to the grid when the price is not beneficial for the customer, to charge the batteries from the grid during the cheapest hours, and to sell electricity from the batteries to the grid during more expensive hours.

Managing Major Consumers

Modbus R2 includes two relays that can control household consumers. The most common application is to limit the operation of a heat pump (e.g., air-water or ground-source heat pump) during expensive price periods with one relay. This allows critical consumers that we cannot control—such as lighting, refrigerators, televisions, computers, etc.—to continue operating using stored energy.

If your heat pump supports the SG Ready function, the second relay can also be used to "use" hot water and heating as "battery power" and to store excess cheap electricity as heat. Such interfaces are available on heat pumps from various manufacturers, including Nime, Thermia, Daikin, Fujitsu, and others. When the batteries are full and electricity is sufficiently cheap, heat pumps with the SG Ready interface can raise the hot water temperature by 5℃. By raising the temperature of a 200-liter boiler by 5℃, 1.1 kWh of energy is stored in the water.

In addition to heat pumps, various electrical devices can be controlled, such as air conditioners, electric boilers, electric heating systems, swimming pools, etc. Below are some examples of typical settings, with all parameters adjustable by the user:

• If electricity is cheaper than €0.007/kWh (energy sales margin, limit electricity sales). For batteries, set them to charge from the grid until they reach 95% capacity.

• Sell from the battery during the most expensive hour of the day with a capacity of 5000W, leaving 50% of the battery capacity for your own use.

• Charge the batteries during one cheaper hour with a capacity of 5000W until the battery reaches 95% charge or until that hour is over.

• If electricity is more expensive than €0.50/kWh, empty the battery, leaving 10% in it.

• Allow the heat pump to operate during 18 cheaper hours.

• If electricity is cheaper than €0.03/kWh and the battery is charged to 95%, and the sun is producing more than 1000W, set the hot water setpoint in the heat pump 15% higher and the heating setpoint 15% higher (for heat pumps with SG Ready functionality).

Flexibility Market – Let Your Batteries Earn Money!

Significant changes are underway in the European electricity system. The continuous growth of renewable energy sources, the increasing share of decentralized generation connected to distribution networks, changing energy consumption habits, and rising demands for energy supply have created a need for new smart solutions.

Modbus R2 allows energy storage systems to connect to the Elering flexibility market via Fusebox, enabling them to earn revenue from the grid by storing excess energy in batteries and selling energy back to the grid during shortages. Connecting battery banks to the flexibility market helps reduce grid overload and the need for fossil fuel-based power plants. Fusebox compensates consumers for their contribution to balancing the grid.

In addition to direct financial savings, we should not forget the environmental aspect, as green electricity is not just what is consumed at home; it also prevents the production of an equivalent amount of electricity that does not need to be transmitted through the grid.

If you have any questions, feel free to reach out to our specialists via the Thunor website or by emailing info@thunor.eu. We also recommend checking out the Qilowatt IT website, and for clarifying questions, you can contact them at info@qilowatt.it.