After much deliberation, the family decided to install solar panels in our holiday home.

When it came to sizing, we set ourselves the goal of avoiding back-feeding, as the rules for this can change all the time and the calculation of the return on investment is fraught with too much uncertainty.

As the summer house is mostly used in summer and therefore our consumption is higher in summer, this fits well with the annual production cycle of solar PV systems. In summer we regularly charge our hybrid car, which means a consumption of 15-20 kWh per day. Circulating and tempering the small swimming pool requires 5kWh of energy per day, and other household consumers (fridge, hobs, air conditioning, etc.) consume on average another 5 kWh. So it can be seen that we are quite heavy consumers in summer, with an average daily consumption of around 30kWh.

Regarding the timing of the consumption, it is possible to match it to the instantaneous production of the generating unit by switching some of the consumers on and off. The swimming pool, the fridge, but also air conditioners are relatively large heat consumers, and car charging can be slid too.

The first step was to monitor the time distribution of actual consumption over a period of one month (this can now be done very cheaply using smart meters connected to the internal wifi network). The required solar panel capacity and the storage to match it were then sized. The system thus consists of a 10kWh battery and 16 solar modules, as this combination yields the best payback figures, assuming that the option of recharging will not come back to us.

In winter, the cottage is converted to a low-temperature control heating – using the heating mode of the air conditioners. The cost of this is of course highly dependent on the weather, but it is certainly considered to be more economical than the case without the use of renewable energy.

When 14-year-old Peter, who lives in the neighborhood, asked to see our equipment, I was happy to show him all the components. He looked at them with interest and then asked me how they were connected. Then he took out his mobile phone and pressed it thoughtfully. I didn’t pay much attention to what he was doing, as teenagers are always busy with their mobile phones.

Peter thanked me for showing him the system and went home. An hour and a half later he turned up again and said he had something to show me. He came in again and showed me on his mobile phone how he could switch off the soul of the installation, the inverter, in a few seconds. I watched in disbelief, certain that only I would have access to the password-protected device.

I had heard a lot about the attacks and threats to which IT equipment is exposed. But it’s one thing to hear something and another to experience it! After all, my house is not the only one with solar panels, and it’s bad to think that Peter’s game is to turn them all off! On a hot summer day, it would be like Peter turning off a large nuclear power plant!

I started looking for a suitable technical solution for protection. Consulting experts, I was surprised to find out how much it would cost. I was told that solutions are being developed to protect the IoT systems I use, which are cheap but provide high security, because the owners of many small systems cannot be expected to purchase expensive solutions.

But there is a need for such solutions. In our country, for example, a system that is shut down by external intervention can lead to frost damage in winter and disruption of comfort in summer. Strangely, the hybrid inverter at the heart of the system is easily accessible by anyone, no high-level hacking required. We have decided to provide this delicate IoT system with anti-piracy protection.

After much enquiry, we met with the IoTAC project specialists. The modular protection system they are developing will be able to protect our household. We will be installing them soon and I will report on the results in an upcoming blog.

Prosumers are households that are both producers and consumers of electricity. A prosumer has a grid-connected decentralized production unit and makes two types of exchanges with the grid: energy imports when the local production is insufficient to match the local consumption and energy exports when local production exceeds its needs.

Prosumers are growing in the energy space as more people generate their own power from distributed energy resources. This is most often accomplished through rooftop solar panels and electric vehicles. Gone are the days when electricity consumption was a one-way street. Today’s electric grid is blurring the lines between power generation and consumption.

The rise of prosumers highlights one of the most exciting trends in renewable energy. These emerging technologies can help preserve the natural environment, drive economic development, and provide more energy choices – spurring even greater competition and innovation in the energy sector.

There are huge expectations from the smart power grid to provide sustainable energy services using a bi-directional flow of data and power enabled by advanced information, communication and control infrastructure. Prosumers are not only important stakeholders of the future smart grids but also have a vital role in peak demand management. Therefore, it is necessary to investigate and review prosumer-based energy management. The process of energy sharing among prosumers involves two key elements: information and communication technologies as well as optimization techniques. The relevant communications technologies include wired, wireless, short and long-range options.

Prosumer deployments are made up of a physical layer that consists of a small-scale electric power generation system and a cyber layer for the necessary supervisory functions. The cyber layer allows power system operators to remotely monitor and control the physical layer and coordinate the energy interactions with the power distribution system (e.g., remote micro inverter upgrades to enable grid integration.) The interconnection between the physical and cyber layer is performed using cyber-physical system (CPS) gateways. These devices enable the physical layer to be managed by grid operators through remote servers over the internet.

Figure 1: Schematic of the prosumer cell in the Distributed Energy Resources (DER) system

There are a couple of new challenges occurring through the growing number of prosumers on the grid.

The first problem is the stability of the grid’s control, which requires the introduction of completely new control paradigms.

The second problem is the protection of the grid against attacks and failures.

Compared with the traditional electrical energy systems, where centralized plants were responsible for generation and distribution of energy, which were relatively easy to protect by physical tools (i.e. guards, fences, etc.), the new prosumer based grids are distributed, partly virtual units, where physical protection is not only impossible but is not sufficient either. Due to the nature of the so-called virtual power plants, and the aggregators, where connections within and out of the unit are IT-based, attacks may not be physical but much more likely will be IT-based. Cyber security, cyber protection must be the key focus.

The more the production of renewable energy grows so increases the ratio of electrical energy in the overall energy balance of the world.  Simultaneously the role of the electrical distribution network, the grid is growing. The grid is a critical infrastructure, and its stability, safety, and security have growing importance for our society.

At the end of the day, the grid is the key infrastructure in our life. It is hard to imagine a greater disaster than the breakdown of the grid.  Life will be pushed back to the Middle Ages, and society will come to a standstill. No food, no water, no transport – the largest disaster one can imagine. Security and privacy are of extreme importance for the smart grid domain.

Such a horrific scenario can be caused by a single computer connected to the net. Therefore, the guaranteed security of the system has vital importance. It is an interesting contradiction, that it is the internet that makes possible the function of the grid, but at the same time, its use causes the largest vulnerability. More prosumers make the grid more sensitive against threats through internet access. Adequate protection measures are needed to be implemented for the safety of our daily life.

There is also another aspect with security relevance to be considered. Control units of the prosumers are artificial intelligent systems. Prosumers are business partners on the grid. They have controllers for optimal business-oriented use of the bidirectional data flow. They work on the traditional trade principle: buy cheap and sell expensive.  The cooperation of the utility (or the aggregator) and the prosumers are similar to the stock exchange and need to be controlled by new solutions (i.e. game theory approach).

The security challenges of the prosumer system are typical for any IoT system. A large number of active endpoints, low computational power in the endpoints, heterogeneous hardware-software system, no standardized construction, many different suppliers and no detailed documentation are the most important problems.

The main goal of the IOTAC project is to develop a comprehensive, standard-compliant security solution for IoT services. One of the testbeds to validate the result of this huge development work is a prosumer cell.