ALWAYS POWERED UP

Cooking food or keeping it cool, switching on lights, doing the laundry, watching the TV, using the telephone, sending e-mails and surfing the Internet – no electricity at home is unimaginable. Likewise, in economic sectors such as industry and commerce, in services and transport, agriculture and public institutions, practically nothing happens without electrical energy.

In light of the ever increasing demand for energy, politics and the economy are now facing some big challenges. The “Energy Outlook” of British Petroleum (BP) expects the global energy demand to increase by 37 percent by 2035. At the same time, climate-damaging CO2 emissions will increase by 25 percent. The balancing act is to meet the huge energy demand economically while conserving the environment at the same time. There is a long way to go before the electricity coming from the socket is environmentally friendly.

Plastic as an Insulation Material
The Röchling Group supports its customers in the energy sector in achieving this in various ways. From energy production to energy distribution. For more than 60 years Röchling as a plastics specialist has produced innovative materials for use with electrical equipment. These products are used worldwide, especially as insulation and construction materials. Manufacturers use the materials, for example, in the development of high-voltage transformers and generators, in converter stations and switchgears as well as for the production of durable and reliable rotor blades for wind turbines. “The materials used must be as individual as the applications are varied,” says Rainer Sanders, General Manager Sales Composites. “Our portfolio contains the right material for every application and we advise our customers accordingly.”

Use in Wind Turbines
Wind energy plays a key role in the development of renewable energies. Today in Germany there are more than 27,000 wind turbines, which are intended to help reduce harmful CO2 emissions resulting from the production of electricity. The rotor blades of the turbines are subjected to very harsh stresses including high winds, top speeds of up to 300 km/h, intense UV radiation and weather conditions. At the same time, there is a constant demand for them to be more efficient, bigger and quieter. Here, Röchling offers a compelling solution with pultruded profiles for spar caps. The profiles are made of glass fiber reinforced or carbon fiber reinforced Durostone® – a high-performance plastic, which combines excellent mechanical, electrical, thermal and chemical properties and offers many advantages compared with traditional materials. In particular, it exhibits a high degree of strength at a low weight.

THE LONG ROAD TO THE POWER SOCKET

Only a few hundred years ago, electrical phenomena such as thunder and lightning were still seen as forces of nature, attributed to gods and sorcerers. In the 17th century, the German engineer Otto von Guericke was among the first to discover that electricity can be generated by friction. In 1752, American politician and scientist Benjamin Franklin flew a kite during a thunderstorm. Hanging from the kite string – in which was braided a metallic thread – was a key. This allowed Franklin to pick up the ambient electrical charge and bring it down from the sky using his metallic conductor.

The widespread use of electricity began in the middle of the 19th century – from the telegraph line in the USA to the lighting of public spaces in Paris and the electric generator. 1882 saw the long-distance transmission of direct current. Four years later, alternating current was being transmitted. In 1891, the first long-distance transmission of three-phase alternating current – as is standard today in energy technology – was successful.

In the 19th century, scientists such as Michael Faraday and Thomas A. Edison discovered that electricity flows through a wire when it is moved by a magnetic field. The idea to create electricity using movement soon led to the invention of dynamos and electrical generators, which convert movement – of a steam engine for example – into electricity. Conversely, electricity can also be converted back into movement, which led to the birth of the electric motor. Electrodynamic processes, which work with the help of magnetic power, are the basis for the modern production and use of electrical energy.

Together with one or two ribs in the rotor blade shell, the spar caps form the skeleton of every rotor blade. To make optimal use of the properties of the glass fibers or carbon fibers, Röchling uses a pultrusion process to process them into profiles that are several hundred meters long and a maximum of 20 centimeters wide. The profiles are rolled up for transport and later cut to the appropriate length for the respective rotor blade. “The profiles are laid next to and above each other on the spar cap and attached to the rotor blade as one unit. The spar caps ensure that the rotor blades do not deflect too much, even in the event of high wind loads,” explains Melanie Book, Application Engineer at Röchling. The profiles are not the only wind turbine components produced by Röchling using high-performance plastics. From molded parts, for example for attaching sensor fibers to electrical insulation components and cable holders, to sliding sheets, on which the wind turbine nacelles turn in the wind, plastics perform outstandingly well.

High Temperatures, High Stress
Whether for renewable energies or conventional energy sources – transformers are always needed in energy technology to interconnect the different voltage levels on a power grid. The task of manufacturers of oil-filled, high-performance transformers is therefore to ensure that their products work safely and reliably even at high operating temperatures and under a high electrical load – and with a service life of more than 30 years. “We developed our insulation materials specially for these requirements,” reports Hans-Jürgen Geers, who is responsible for development as General Manager of Marketing & Technology. This includes Lignostone® Transformerwood®, a material that combines excellent electrical and thermal insulation properties with very good oil absorption, low weight, and a high mechanical and electrical loading capacity. Typical components include thrust rings, platforms, pressure beams, shield rings, pressure segments and fasteners.

In the Automotive division, the topic of electricity has become a persistent issue over the past few years. Electric and hybrid vehicles are seen as “climate savers” because they are intended to make a significant contribution to reducing greenhouse gas emissions. If electric vehicles are charged with electricity from renewable energy sources, they are practically CO2 neutral. Meanwhile, new battery technologies are making possible a range of more than 400 kilometers.

Electric Cars Are Not a New Discovery
However, electric cars are by no means a new discovery. Electromobility has been in competition with vehicles with internal combustion engines since the end of the 19th century. Electric cars were smoother, easier to maintain and – unlike vehicles with combustion engines – did not have to be laboriously started using a starting handle. However, when the electronic starter was invented, vehicles with combustion engines prevailed due to their longer range and the cheaper fuel. From then on, “electrics” became a niche product even though there were briefly some very promising concepts on the market, such as the Saturn EV1 from General Motors. Then, in 2008, Tesla released its Roadster, proving that electric cars can be fun. Meanwhile, all the well-known international car manufacturers are working on improving the everyday usability of their vehicles.

This also requires ideas and developments from suppliers, especially related to batteries. It is not only the performance, size and weight of the batteries that need to be optimized – how they are housed in the vehicle is also a key issue. The keywords here are crash safety, impermeability and cooling. Röchling Automotive has already released several innovations on the market in this area and is continuing to research innovative solutions.

WHAT IS ELECTRICAL ENERGY?

It starts with the atom. The shell of the atom consists of negatively charged particles, electrons, which revolve around the nucleus and always strive for a neutral state. The atoms of substances that can conduct electricity release their electrons easily. In non-conductive substances, the electrons are always tightly bound to an atom.

An electrical current occurs when electrons move along a copper wire, for example. The term “ampere” indicates the amount of electrical current. A force must be generated to ensure that the free electrons move along a conductor in one direction. This force is created when there is an excess of electrons on one side of the conductor and a shortage of electrons on the other. The size of this difference is called the voltage.

A distinction is also made between direct current and alternating current. Direct current is used in battery-operated devices, such as flashlights. The particles always move in the same direction, from one pole to the other. The electric current that comes out of power sockets is alternating current, where the electrons move in one direction and then immediately move in the other direction. The positive and negative terminals swap functions in a fraction of a second – 50 times per second in the power grid in Germany. More energy is lost when transmitting alternating current compared with direct current. This means that it is easier to convert voltages using alternating current – from a high voltage to a low voltage, for example.

For traction batteries, i.e. energy storage systems, used to power electric vehicles, Röchling has developed a range of plastic components, such as battery housing uppers, covers, cell frames and insulation plates, which are already in production. The lightweight, customizable and multifunctional battery housing uppers are manufactured from the material SMC (sheet molding compound). The next generation of housing covers will be produced using the new material Stratura® Hybrid. The hybrid material combines lightweight, acoustically effective and thermally insulating glass fiber lightweight reinforced thermoplastics (LWRT) created using pressing technology and microperforated aluminum layers. This has several advantages. In the event of a collision, the material evenly absorbs the energy released. The aluminum layers work together to ensure enhanced mechanical properties and optimal electromagnetic shielding – potentially damaging magnetic fields cannot harm the sensitive battery cells thanks to Stratura® Hybrid. Stratura® Hybrid also has good acoustic properties. Fastening elements for the battery cells or structural reinforcements can be integrated directly into the plastic housing using sophisticated manufacturing techniques. “We already produce in series battery housing uppers for the BMW 2 Series Active Tourer Hybrid, using various manufacturing technologies in the process,” says Johannes Biermann, Head of Product Line New Business Green Car.

Research into Inductive Charging Systems
The New Business Green Car product line is using internal studies to concentrate on the various possibilities for efficiently regulating the temperature of electric vehicles and, thereby, maintaining the “comfortable temperature” of the lithium-ion batteries. “We are also intensively researching inductive charging systems for electric vehicles, which make it possible to position a vehicle on a charging surface and charge it wirelessly,” reports Biermann. Here, specialists from Röchling’s Automotive division are working together with their colleagues from the Industrial division. A primary charging coil needs to be embedded in the floor and a secondary charging coil integrated in the vehicle underbody. When both are perfectly aligned, the induction charging process begins, using electromagnetic fields. It is as user friendly as it gets.

 
 

Christiane Müller
Freelance Journalist
Phone: +49 40 32039535
chm.texte@me.com

Photos © epitavi, orion_eff, Jemastock – fotolia.com, JamesAchard, GiorgioMagini, wastesoul – iStock.com