A successful energy transition requires a new infrastructure

Even today, when we are still a long way from a 100 percent green energy supply, breakdowns in the grid occur time and again: In January of this year, France faced serious problems with its power supply – yet again, as the combination of aging nuclear reactors and cold temperatures regularly causes electricity supply bottlenecks.

That same month, an incident in southeastern Europe also caused widespread disruptions throughout the European interconnected grid. First, an automatic overcurrent protection system in a Croatian substation failed and disrupted an important connection line. Within only a short time, the alternative transmission lines were also overloaded and caused further disconnections. In fact, this disconnection actually resulted in an oversupply of electricity in the southeast and a simultaneous deficit in the northwest. Correcting the issue required the targeted shutdown of large industrial power consumers in order to avoid further outages. 

Structural problems in the interconnected grid

The first electricity grids were designed to be local and supplied only a single town or factory with power. As early as the 1920s, however, the foundation for larger-scale interconnection was laid with the north-south line in Germany. The idea at the time was to use hydropower resources from the Alps to satisfy the Ruhr region’s insatiable hunger for energy.

This is one of the underlying principles of interconnection: to produce electricity where the resources are located and then redistribute it to consumers. Once large thermal power plants took over the main burden of energy production, however, grid balancing also became an issue. Large nuclear or coal-fired power plants can only be run at a relatively constant output and cannot be ramped up or down spontaneously, even though the demand for electricity fluctuates over the course of the day. This means solutions for how to deal with surplus electricity had to be found. These include pumped storage power plants, load control in energy-intensive industries, as well as dual-tariff meters and night storage heaters in private households. 

The basic design of an interconnected grid is geared towards long-term, plannable and constant generation at a few main power plants, from where energy then needs to be distributed as efficiently as possible while balancing out local differences in supply and demand. Due to climate change, however, energy production has experienced a radical shift in recent years, which in itself is a positive development. 

Despite the fact that wind and solar power are decentralized resources, the power they produce can now be planned relatively well, thanks to improved weather forecasts and the possibilities offered by digitalization. Nevertheless, production is often ramped up and down in quick succession, and the grid, which dates back to the era of nuclear power and coal, is simply not made for this. Given that it is already struggling, the European interconnected grid in its current form will probably not be able to cope with fully renewable power generation. But what is the alternative? 

The grid of the future: flexible and cellular 

Wind and solar power plants are far less dependent on specific local factors than the old large-scale power plants. Nuclear reactors need large bodies of water for cooling, and the same is true of hydroelectric power plants, which is why they are frequently located next to reservoirs in the mountains. Similarly, coal-powered plants were often built directly adjacent to open-pit mines to ensure their supply of lignite.

Photovoltaic systems, on the other hand, can be mounted on any roof, and wind turbines can likewise be erected in a wide variety of locations. At the same time, renewable power is both more unpredictable and much more decentralized than traditional modes of generation, so that some rethinking at the grid level is nevertheless required. Locally generated electricity should also be used and (in the case of surpluses) stored locally. The ultimate goal of reforming the grid should therefore be the creation of a cellular energy system.

Such a holistic approach also takes transportation, heating and industry into consideration. The integration of electromobility is particularly significant in this regard. In a traditional approach, the large-scale spread of electric vehicles is often seen as an additional burden on the grid. This is based on the fear that simultaneous charging of many vehicles could lead to grid overload, an issue that also affects conventional grids. 

In a cellular model, however, electric vehicles are no longer merely seen as consumers but as part of the integrated energy grid. In practice, they can thus contribute to balancing the grid through time-controlled, intelligent charging during generation peaks. The vehicle-to-grid approach even goes one step further: Vehicles that are not being used can feed energy back into the grid and thus support short-term frequency control. 

In addition, stationary storage facilities constitute an essential pillar of the flexible electricity grid of the future. For example, one interesting approach to the long-term storage of green energy is power-to-gas, which refers to the electrolytic production of hydrogen using green electricity. The hydrogen produced this way could then either be converted back into electricity later on or used as clean fuel. While hydrogen production by way of electrolysis has been around for quite some time, it is not yet economically viable.

This will change as prices for renewables fall and green hydrogen becomes more attractive as a business case. The technology is already much further advanced when it comes short-term energy storage by means of batteries – in fact, the necessary solutions are already commercially available. 

Local energy management 

At Eaton, our approach is to view individual buildings as the smallest local energy unit. Such a unit includes the storage, distribution and delivery of energy (also in the form of charging stations), and may optionally also include generation. This Buildings-as-a-Grid approach is aimed at transforming buildings into local energy centers. The Johan Cruijff ArenA is one example of an energy center that has already been realized. A battery storage system with a capacity of 3 megawatts was installed in the stadium’s multi-story car park, which not only ensures power in the event of an emergency but can also perform local grid balancing functions. In addition to bidirectional charging stations, the arena’s energy storage system also incorporates so-called second-life batteries, which are batteries that are no longer powerful enough to be used in cars. 

In new buildings, such holistic energy considerations, including storage systems, should become the rule rather than the exception. This will play an important part in the localization and flexibilization of electricity, which are crucial for the development of a modern grid and the urgently needed energy transition. For building owners, now is definitely the time to act: They can help create solutions for a clean future and save energy costs at the same time. Not sure where to start? We are here to help with advice and support.