Extreme price volatility in the Bulgarian Energy Exchange provides excellent conditions for demand side management

By Mari Kristine Buckholm, Smart Innovation Norway 19. March 2019

The Bulgarian INVADE pilot is now making its final preparation steps to go live. So far, the testing and results have been sensational.

“All necessary infrastructure has been successfully installed and has passed the initial security and exploitation tests,“ says Dimitar Stanev, Deputy Director Business Development at Albena and INVADE pilot leader.

He explains that the Albena pilot has a 201-kWh battery that will help shape their load profile. They have also installed a small PV system that will bring generation volatility into the local energy system. With the help of the battery, Albena will balance the renewable energy generation, prevent feeding excess energy into the middle voltage grid and in that way contribute to the overall system stability.

“In order to strengthen the effect of demand side management, we have also achieved an efficient way to shift the demand of certain loads – in our case the generation of domestic hot water. The boiler installations, that care for hot water preparation represent huge potential for energy storage. With the help of programmable logic controllers, we have managed to shift the electrical consumption to off-peak times and store the thermal energy for later use,” notes Stanev.

Power flow optimization

The INVADE Integrated Platform (IIP) is a powerful tool for power flow optimization. Enhanced optimization algorithms are implemented in it, and it can provide control signals for power flow adjustments. The optimizations are done in various ways depending on the contracts that are initially configured.

“It is great that each pilot can configure their own contracts which reflect the situation in their country. In our pilot we supply the IIP with metering data of various devices – controllable and non-controllable loads, battery, PV system, EV chargers, etc.,” remarks Stanev.

The INVADE Integrated Platform already has updated information about prices of the energy products on the Independent Bulgarian Energy Exchange (IBEX) and considers local weather information.

“This is important because the IIP has the possibility to consider all energy sources, including predictions of local RES-generation that depends on the local weather conditions. The results of the performed calculations are then sent back to Albena and implemented by the controlling devices,” explains Stanev.

The control signals are time series in which we “tell” the devices when to use electrical energy and how much of it. In example if the battery State of Charge (SOC) is 90% and the current hourly prices on the day ahead market are low, the battery is told to wait some time. When the prices go high again, a control signal “discharge” is sent to the battery, so it lowers the overall local energy consumption.

New billing method = High volatility

Since the beginning of the INVADE project, Albena has been billed on a flat tariff that does not consider the prices on the IBEX.

“This way we had an important advantage because we could predict precisely our energy costs for the summer season and include them into our prices for the touristic product,” Stanev points out.

Figure 1 shows the structure of the costs Albena has for electrical energy. The most significant cost is energy, which represents 58% of the whole.

Figure 1: Structure of the average electrical energy costs of Albena.

“Since the beginning of December 2018, the Bulgarian energy legislation made it obligatory for the industry to trade all necessary energy on the IBEX, so our energy supplier began to bill us based on the IBEX day-ahead market prices. Suddenly, the traded volumes increased which has caused high volatility of the prices – in some hours the prices have reached 150€/MWh,” notes Stanev.

Figure 2 (below) shows quite clearly how the average price increased in December and January, and it does not include the additional net costs and various taxes. The average price increased by more than 22€/MWh compared to November.

Figure 2: Effective energy prices for Albena per MWh.


“Even more important, is the daily price development. On Figure 2, one can see the minimum and maximum daily price on the IBEX. The spread is suitable for demand side management – use energy in low-priced-hours and generate energy in high-priced-hours,” emphasizes Stanev.

Figure 3: IBEX Min and Max day ahead market prices January 2019.


Flexibility benefits

INVADE creates and utilizes flexibility that was created by various devices. This brings financial benefits due to adjusted power flows according to the energy prices.

“Albena is able to shape its load profile to prevent imbalance penalties due to unpredicted circumstances. The flexibility that is utilized by INVADE can also be used to prevent physical power flow congestions and this way minimize necessary infrastructure investments,” explains Stanev. He adds:

“A good example is hotel boiler rooms that use diesel as input energy. When we try to shut down such installations, we face the problem that the electrical cables are not capable of transmitting the necessary peak power for domestic hot water preparation. Smart consumption in this case is inevitable and INVADE provides the intelligence for it.”

Another benefit for Albena, Stanev points out, is the image improvement of the company: Albena is constantly developing new efficient ways for energy utilization that creates added value for their customers.

Applying local optimizations

Albena started in the beginning of December during some very high-priced-hours to manually control the battery according to the prices on IBEX. Thus, the financial benefits are still not significant, because the local efficiencies were performed occasionally.

“We are now preparing for the summer season when we will receive control signals from the IIP and the optimizations will be performed automatically. The financial benefits are highly dependent on the IBEX prices. However, our analysis shows that the battery itself could earn up to 100€/day cost savings,” concludes Stanev.


Social media

INVADE updates

Science blog: INVADE inspired by Amazon and Airbnb

The work package WP9: Business models and market structures, led by INVADE project partner Lyse has put forward a market structure for platform-based business models inspired by disruptive companies like Amazon and Airbnb. (3 weeks ago)

@INVADEH2020 : Work package 9 Business models and market structures, led by project partner Lyse has put forward a market structur… https://t.co/xC50UvJELK ( - 3 weeks ago)

@INVADEH2020 : "The work package WP9: Business models and market structures, led by INVADE project partner Lyse has put forward a market structure for platform-based business models inspired by disruptive companies like Amazon and Airbnb," writes Smart Innovation Norway researcher Bryan Pellerin in this INVADE science blog article. Read more: ( - 3 weeks ago)

@INVADEH2020 : Renewable energies and electric vehicles (EVs) change the way we consume and produce electricity. It also changes the way those who manage and distribute it must think about the electricity system – to always provide the best possible service for the connected costumers. The goal of the EU funded Horizon2020 project INVADE is to greatly speed up this process, by showing that the technologies and solutions we have today, only must be connected in new ways to solve the challenges of tomorrow. Watch the official INVADE film to understand how: ( - 1 month ago)

@INVADEH2020 : As part of the European Sustainable Energy Week (EUSEW), the Sustainable energy days in Albena last week was an informative event/workshop about the innovations and optimizations in the energy field the company is introducing (https://www.eusew.eu/energy-days/eu-sustainable-energy-days-albena-bulgaria). One of the projects presented was the EU Horizon2020 project INVADE (www.h2020invade.eu). Two INVADE partners were represented, Albena Resort, Bulgaria and Smart Innovation Norway. Researcher Bryan Pellerin presented INVADE to the local stakeholders and got to exchange with Albena’s partners (both hotel managers, guests and more technical people) about what the project is addressing. "This is a part of our work package 3 focused on exploitation. We also toured their facilities (farm, wine yards, biogas plant), which was very interactive and puts INVADE in context of their other sustainability activities," explains Pellerin. ( - 1 month ago)

@INVADEH2020 : This week is @euenergyweek, the annual flagship event organised by the @EU_Commission. Achieving #sustainable… https://t.co/wWKrc2VOQp ( - 2 months ago)

@INVADEH2020 : This week is the EU Sustainable Energy Week (EUSEW), the annual flagship event organised by the European Commission. Achieving Sustainable Energy is within the INVADE goals. HOLD THE DATE for "INVADE Barcelona 2019" on the 20th of November, as a side event of Smart City Expo World Congress, to see what we have done in the project. ( - 2 months ago)

@INVADEH2020 : In the INVADE project, a central delivery is the cloud-based Integrated INVADE platform, which will be used by the Flexibility Operator to manage #flexibility from flexibility providers and offer this to flexibility customers. It is crucial to specify how data can be sent to and from the Integrated INVADE platform through its communication platform API pilot by Pilot. You can access Deliverable 7.2 "Specification of the CP-API-functions" at https://h2020invade.eu/deliverables/ ( - 2 months ago)

The pilots have begun testing the INVADE integrated platform: “An excellent example of how we can bring flexibility and storage technology to the end-users”

In the end of May, the INVADE consortium was gathered in the Netherlands. During the two-day meeting, all five pilot owners presented their progress to the project partners. (2 months ago)

@INVADEH2020 : In the end of May, the INVADE consortium was gathered in the Netherlands. During the two-day meeting, all five pilo… https://t.co/H7CYKd3zyO ( - 2 months ago)