Renewables have become a serious part of the energy mix. According to the International Energy Agency power generation from renewable energies – including hydro power – will treble worldwide by 2040. We want to play a major role in the energy transition.
One of our aims is to manage the volatility of renewables, which produce varying amounts of electricity depending on the weather, by means of innovative storage technologies. Other focus areas are our Carbon2Chem project and load management, i.e. matching energy use to energy supply.
We have set ourselves ambitious energy efficiency targets for our own processes. By 2020 we want to improve our efficiency by 3.5 terawatts. That translates roughly into 1.43 million tons of CO2.
|Photovoltaics||33 GW||~58 GW|
|Wind energy||31 GW||~80 GW|
|Share of renewables in the energy mix||23.5%||~59%*|
CO2 as raw material
We have launched the first cross-industry initiative to utilize emissions from steel production. Carbon2Chem is the name of the project in which steel mill waste gases are to be used as raw materials for the production of chemicals. Carbon2Chem contributes not just to the transition to renewables but also to climate protection.
Waste gases are generated at various points in a steel mill. Among other things they contain nitrogen, hydrogen, methane, carbon monoxide, and carbon dioxide (CO2.). Today we use these gases as a source of energy. They are burned in power stations and supply electricity for our steel production.
The aim of the long-term Carbon2Chem project is to use steel mill waste gas as a raw material. The idea is for a nearby chemical plant to use the gas as a starting material for the production of fuels and fertilizers. The CO2. contained in the waste gas would also be converted.
The concept is expected to be ready for industrial-scale use by around 2030. Of course, our steel mill will then still need electricity. This is where renewable energies come in: When wind and solar deliver excess electricity, we will use it in our steelmaking processes. The waste gases would then be split, so part is available for the production of chemicals.
We also want to use the “green electricity” to produce more hydrogen than is already contained in the waste gas. We need the additional hydrogen to convert the CO2.. Carbon dioxide is a very stable chemical compound, and it takes a lot of energy – such as that contained in the hydrogen – to break it down.
The market for energy storage systems is “about to explode,” say analysts at IHS Technology in a recent study. Navigant Research forecasts 21.8 gigawatts of new storage capacity from 2013 to 2023. Boston Consulting reckons that 330 gigawatts of new capacity will be created by 2030. Whichever way you look at it, the demand for storage systems is huge, and companies which can offer high-performance, low-cost solutions should be able to do good business in the future.
Demand for storage is so high because renewable energies are becoming increasingly established on the market. According to the International Energy Agency IEA, electricity generation from renewable sources will roughly treble by 2040. The problem is that wind and solar are volatile, i.e. the amount of energy they deliver fluctuates sharply. Energy consumers, however, need a constant power supply. Storage systems are therefore needed to compensate for periods of low supply. thyssenkrupp is entering the race with two storage technologies: redox flow batteries and water electrolysis. The aim behind both approaches is to increase capacity and power output while reducing costs.
Redox flow batteries store electricity as chemical energy in two tanks filled with salts dissolved in inorganic acids. The tanks are connected to one or more electrochemical cells that charge or discharge the batteries. Redox flow batteries operate at efficiency levels of up to 80 percent. The surface area of the cells determines the power output of the batteries.
Our aim is to significantly increase the cell area and thus the battery output. Capacity can already be changed easily by increasing the size of the tanks. To date, the cell area for practical use has been around 40 square centimeters. We want to achieve a cell size of over 2.50 square meters. That would make it possible to build industrial storage systems with an initial output of 20 megawatts and a capacity of 200 megawatt hours.
Our experts have already succeeded in increasing output by a factor of ten. A further ten-fold increase will be achieved shortly. The final cell size should be reached before the end of 2016.
thyssenkrupp’s contribution to water electrolysis is expected to be market-ready from early 2017. In this technology water is separated into hydrogen and oxygen with the help of electricity. The hydrogen can be stored as an energy source, converted back into electricity when required, or used for fuel cells or for the production of chemicals such as methane, methanol, and ammonia.
Our development efforts are helped by our long-standing experience in chlor-alkali electrolysis. Water electrolysis uses very similar components. Chlor-alkali electrolysis already produces hydrogen as a byproduct. Only recently we sold our 100,000th chlor-alkali electrolysis unit.
An initial lab-scale plant has already been built. The next planned step in the development process is a pilot plant.
The sun doesn’t always shine, and the wind doesn’t always blow. Renewable energies are volatile, so the question is whether energy consumption can be organized so that it matches supply.
Industrial consumers offer the greatest potential. They are the biggest users of energy in Germany by some distance. Our steel mill in Duisburg alone uses as much energy as the city of Berlin. The difference is that Berlin has three million individual consumers, the steel mill just one.
This is where load management comes in: The idea is for large industrial electricity consumers to match their electricity demand and thus their production workflows to the supply of renewable energies. For this they need to make their processes and organization smarter and more flexible. In this way industry can make an important contribution to grid stability and the success of the transition to renewables.
The cement industry is another major electricity consumer in Germany. There are several processes in cement production which can easily be interrupted – for example the preparation of raw materials could be staggered. Energy-intensive processes could be scheduled to start when the supply of renewables is plentiful. The latest electricity price could be used as a signal. When energy is freely available, the price drops – and production can start.
One helpful factor in cross-energy management is that the supply of renewable energies can be forecast – like the weather – with a sufficient degree of accuracy, providing a good basis for flexible production planning.