The bar is high: by 2050, renewable resources are predicted to cover almost the entire energy supply worldwide. Not an unrealistic goal, because low prices mean they are now competitive with fossil fuels. Nevertheless, the energy transition remains a complex task.
is when solar energy is expected to cover about one fifth of Egypt's electricity needs.
Renewables are the key technologies for climate protection and sustainability. More and more countries around the world are relying on natural resources such as sun and wind. These include emerging economies such as India and China, in response to their own rapidly growing energy needs. China in particular is moving up a gear. Although the world's second-largest economy still burns almost half of the world's coal, at the same time Chinese energy companies are preparing to conquer international markets in the green electricity sector. According to the McKinsey Global Institute, the densely populated country in East Asia invests over 100 billion annually in the development of green technologies, more than the US and Europe combined. China is already the world's largest manufacturer, installer and exporter of solar modules, wind turbines and electric vehicles.
A few thousand kilometres away there is a lot going on. In southern Spain, BayWa AG has built the "Don Rodrigo" solar power station via its subsidiary BayWa r.e. renewable energy GmbH. The farm has a total output of 175 megawatts. This makes it on a par with a conventional peak-load power station: the 300 gigawatt hours it generates can supply power to around 93,000 Spanish households each year. This is the first time in Europe that green electricity has been generated at market prices without any subsidies.
When we talk about renewable forms of energy, we usually mean wind and solar energy. In principle, these two technologies complement each other well, as often it is windy when the sun is not shining and vice versa. Due to these natural conditions, however, both only provide a fluctuating feed-in to the grid, according to whether the sun is shining or the wind is blowing. The entire power grid must adapt to this and become more flexible. In addition to optimum load management, innovative storage technologies play an important role in ensuring continued supply and system security. They serve to balance production and consumption and to decouple them over time. As such, they make a decisive contribution to grid stability. This is increasingly coming to the fore. After all, fleets of cars and lorries will one day be fully electrically powered.
In addition to batteries and rechargeable batteries, there are other ways of storing electrical energy, for example in the form of water in pumped storage facilities. Or renewable electricity is used to split water into hydrogen and oxygen by electrolysis in power-to-gas plants. The resulting hydrogen can be stored in the gas infrastructure and, if necessary, also re-introduced into electricity, because up to a certain percentage pure hydrogen can also be transported and stored in the existing gas network as a mixture with natural gas. Adding carbon dioxide turns hydrogen into synthetic methane. It is chemically identical to fossil and biogenic natural gas and can be used in the same way. These processes allow hydrogen to be used for heat supply and industrial processes, or be liquefied as a fuel.
Batteries are also used as electrochemical storage devices. The majority are lithium-ion batteries, whose production costs have fallen by up to 80 percent in recent years. The world's largest lithium-ion battery is in Australia, has an output of 100 megawatts and was developed by the American electric car manufacturer Tesla. It can be used to supply 30,000 households with energy for up to one hour in the event of a power failure. And the next generation of rechargeable power sources is already in the starting blocks: magnesium batteries are set to provide even higher outputs. They are considered safe, cheaper and do not require valuable raw materials.
The energy transition is inextricably linked with digitalisation. It is the basis for linking all existing solutions efficiently and intelligently. Only digitally networked storage, renewable energy facilities and flexible consumers form a smart network, the Smart Grid (see column to the side). Virtual power stations(see column to the side),such as those operated by BayWa r.e., are an important component of this networking. Virtual power stations can network any number of wind farms, photovoltaic and biogas plants or block heating and hydroelectric power stations as well as power storage facilities and consumers, via one central communication platform. For example, when the wind is calm or the sun is not shining, biogas plants can be automatically ramped up or consumers throttled. By connecting to a virtual power station, flexible producers, consumers and storage facilities can always provide or obtain electricity exactly when it is most beneficial to the overall system and, at the same time, most lucrative from an economical perspective.
A large number of companies have established themselves in the field of new strategies based on renewable energies. Every day, the business areas grow and innovations spring onto the market. Just recently, for example, a start-up company based in Australia patented an acoustic monitoring system for rotor blades: it is designed to reduce the service and maintenance costs of wind turbines by using software to estimate the "health status" of the turbine.
Overall, it can be said that renewables have become the driving force behind a completely new energy infrastructure. Increasing energy efficiency is another key to success. Experts, politicians and scientists agree that the complex processes take time to implement. But there is one thing to remember: the energy transition is not just a state of mind, but has to be actively implemented. And we can all contribute to this. Lower energy consumption in favour of clean air, better quality of life and prosperity is therefore still a social challenge – around the globe.
