Welcome to the first part of the interview with Boris Turha, Senior Development Engineer in the Technological Development Department at Electro Ljubljana. This is the second interview of the 5th season of Smart Talks with Jovan and this time we are hearing first-hand experiences of Smart Energy Management from DSO, Slovenia.
Find out below how they are trying to reduce energy consumption and bring flexibility to the grid.

What is Smart Energy Management in Households and what are the differences compared to Smart Home from your perspective and your experience?

For some people, a smart house means the possibility of remotely turning on or off appliances using simple wireless plugs or automatic (smart) blind management. For me, smart energy management is a system that automatically manages devices and enables energy savings for heating and cooling a home.

HEMS is still expensive for people, so for now, I see it only partially implemented. One example is smart charging stations, which check the overall household consumption, and when the consumption reaches a defined limit, these stations reduce the charging power. Eventually, all home charging stations are smart nowadays, and the price of them will not be so high compared to non-smart ones. Also, I think it’s important to mention that we don’t explicitly need a smart charging station because electric cars are also smart nowadays. 

Inverters in solar power plants could also be smart if they are integrated with smart meter. Let’s say that in the case that the charger or inverter is smart, the price difference could be approximately around 500 euros because you need to install a separate smart metering device.

As DSO, we don’t allow anyone to connect directly to the main meter for billing. There is a port for consumers on a smart meter like P1, but how many customers have an additional wire from the metering cabinet where the meter is installed and a line from the car charger? The issue that I see is that communication is not wireless, instead a wired solution. But wireless communication can also be problematic since some meters are installed in metal cabinets and wireless communication is not possible.

The natural place for smart energy management devices is near the meter, because the consumption of the house is measured by the meter. The problem is the connectivity of those devices because they will be installed in metal enclosures. The second solution is to send meter data to the cloud using some additional device that connects to the P1 port, in which case the smart energy management device can be installed anywhere in the house and get consumption data from the cloud.  

What are your personal experiences regarding Smart Energy Management at Households so far? You are holding the position of DSO, can you tell us a little bit more about work related to Smart Energy Management at Households in that area/group/organization?

As DSO we don’t have any information if a household has Smart Energy Management or not. Based on electrical energy consumption we can assume that people use electricity for heating or cooling, or if photo voltaic is installed.

The one way to achieve energy management is by price. If the price of energy is high the consumption will reduce. The modern meters have also functionality of limiting power, and this limit is set by DSO. It can be changed by DSO via software in real time in case you have point-to-point communication with the meter. But, if you have a PLC communication and there is a concentrator in the substation, the possibility of real time limit setting is very low. 

In my home, I successfully built an Arduino-based reader that taps into the port of my meter. I connected a four-inch LCD touchscreen to it that displays my power consumption every minute, and I’ve since upgraded it to show monthly and yearly consumption as well. Recently, I’ve started making further upgrades, including a feature that will shut off my heat pump when a certain power threshold is reached. This is particularly relevant because, network charge tariff in Slovenia will change. Currently there are only two tariffs for energy and one price for power, based on main fuses.  From July 2024 there will be three tariffs per day with two seasons for the energy and power will be calculated based on 15-minute power intervals. The bigger part of network charge will be the price for power, since power in the high season and peak tariff will be 4.7 higher than current. But charge for network energy will be 45% lower.

I also have a small solar photovoltaic (PV) system installed on my roof. Since my yearly consumption is between 6 and 7 MWh, and because of net-metering, I installed only a 6.4 kWp solar power plant. In Slovenia, solar power plants on households that receive connection approval until end of 2023 have self-supply with yearly net-metering. At the end of the year, the supplier makes annual accounting, and if the self-supply solar powerplant fully covers the consumption during the whole year, consumption is not charged. Last year, my solar power plant produced about 7000 kWh, but I ended up with 100-150 kWh left. As a result, not only did I avoid any electricity bills, but my energy supplier also paid me that difference of kWh. I have a contract with my supplier that he pays me 1 euro per MWh for my electricity production. Some other suppliers pay much more for excessively energy. If my consumption was bigger than production of PV I pay about 200 euros per MWh.

The idea of limitation can be implemented with point-to-point smart metering systems. But DSO can only set the limit on the main meter and when the limitation is reached, the meter will disconnect the whole consumption. It would be better if there was a smart home energy management device to receive information about the new limit from DSO and handle home energy consumption by managing household devices one by one.

We need direct communication with the customer if we want to be successful in flexibility. My experience is that customers are not so interested in cooperation due to a lack of information, but if we implement flexibility requirements in the services and different prices, maybe we will have active customers in this. The issue is that we as DSO can’t set different tariff prices because the price is now set by the national authority agency, and we can’t do anything about it. Suppliers have their own prices. 

We were not able to achieve much flexibility even by going through aggregators because they didn’t manage to inform the customers what they needed to do and what benefits they would get if they offered their flexibility to an aggregator. It is a lot of work in the field, and I’m not sure if the suppliers are interested in this. The idea was that the supplier becomes an aggregator that uses this flexibility for its own needs, but only theoretically, we don’t have so much practice in Slovenia.

What do you think, what is the main purpose of Smart Energy Management?

The main purpose should be to lower costs for energy by shifting consumption to the time when PV is producing energy. Smart energy management can also manage energy storage and charging stations for electric vehicles if they are installed. 

In Slovenia, some PV vendors offer smart energy management, which includes energy storage and smart charging stations. Since the vendor is associated with the energy supplier, it manages energy storage for balancing as the supplier (reducing deviations of actual consumption versus what the supplier had bought on a forward and day-ahead basis). 

What are the benefits for the key stakeholders (distribution companies, suppliers, homeowners, etc.) when using Smart Energy Management in households?

Smart Energy Management is firstly used by homeowners to lower their energy expenses by shifting consumption to lower tariffs or to lower peak power. As I answered in a previous question, suppliers can also use it for balancing purposes. 

If we go one step further, suppliers could offer that flexibility of electrical power to distribution companies and even to transmission companies. Or the owner of Smart Energy Management could offer its flexibility to local distribution companies. In Elektro Ljubljana, we established a flexibility platform where consumers or aggregators can offer flexibility bids.

Conclusions:

The national regulator will increase the price of electricity during peak hours to manage energy consumption. DSO could set power limitations in the main meter for the whole household’s consumption. It would be better if the smart home energy management device handles the home energy consumption by managing household devices within the limit set by DSO.

Smart Energy Management in Households can help bring flexibility to the network and bring benefits to DSO, but it can also lower energy costs for customers by shifting consumption to the time when photovoltaic is producing energy and by using energy storage and charging stations for electric vehicle management.

Question for the audience

Are the advantages offered by HEMS sufficient to serve as the primary impulse for its greater implementation?