Issue link: https://fhpublishing.uberflip.com/i/819678
NETWORK / 29 / may 2017 neutral operation is clean air. as the name suggests, it's a compo- sition of 80 per cent nitrogen and 20 per cent oxygen. This offers several benefits for the customer: l it has no global warming or ozone depletion potential; l it is a highly stable, non-toxic and non-flammable gas; l it has a low boiling point, and therefore works even in very cold conditions; l its compatibility with various materials is well-established; l it is carbon dioxide-free with no risk that carbon decompo- sition will affect its perfor- mance characteristics; l it is free of fluorinated gases (F-Gas) and therefore is very safe and has very low require- ments with regard to train- ing, transport, installation, operation, maintenance and recycling; l unlike F-gases, there are no strict regulations, documenta- tion and reporting require- ments for clean air; and l there are no carbon-compen- sation costs or risk of future taxes or compensation be- cause of stricter legislations. Therefore, vacuum switching with clean air technology offers an environmentally sustainable technology while delivering maxi- mum value for the customer. What is the current portfolio of Siemens Blue products? We are saying that green is not enough. as market leaders, we are going beyond the exist- ing green standards. The new Siemens Blue portfolio is created for the future of energy – our products have to meet a series of strict criteria to be labelled Blue: l No fluorinated gases. l No greenhouse gas emissions during operation. l Using environmentally safe materials. l Lowest operation, mainte- nance and recycling costs. With Siemens Blue, we aim to give our customers the ability to modernise and extend their networks but at the same time re- duce their ecological footprint to a vast extent, and without having to compromise on performance or economy. What was the thought behind pursuing clean air technology for the Siemens Blue portfolio? Vacuum interruption with clean air technology is, in our opinion, the most suitable product for the sustainability requirements of network operators. We analysed several alterna- tives, but they all had drawbacks. For example, other gas mixtures generally suffer from decompo- sition issues during switching and have specific gas storage, handling and maintenance requirements to ensure integrity and performance. The long-term behaviour of these gas mixtures is still to be proven. Clean air has none of these drawbacks – it's very easy to store and handle, it's suitable for temperatures as low as minus 50 degrees and there is no carbon dioxide, so no risk of carbon decomposition. How will Siemens develop and extend the portfolio in future? For Siemens, vacuum technology and clean-air insulation is the ba- sis for further developments. The next steps are to look at extending the Blue range of current and voltage transformers up to 245kV by 2018 and to 420kV by 2020. For GIS, we are now developing a 170kV Blue product. In summary, if you look at the history of the switchgear industry, the introduction of SF 6 gas brought about a revolution in substation design. We are now looking at the next big technical revolution with the use of vacuum and clean air products. Over the next ten years we will ramp up our development activities to serve markets across the voltage range all the way up to 420kV. Lead-acid/ flywheel The first question people ask is how can two such different technologies work together – one is electromechanical, the other is the decades old electrochemical work-horse used to keep anything from forklis to data- centres operating. The key is how the technologies work. Flywheels offer extremely fast cycling capabilities, but only for short periods of time with small quantities of energy. Lead- acid batteries can meet supply demands for much longer, albeit with limitations on their depth of discharge and cyclability. This system makes the most of both tech- nologies, using energy from the flywheel until demand overtakes its available capac- ity, at about 50%, then the lead-acid battery takes over. A demonstration project in Rhode, County Offaly in Ireland – led by Schwungrad Energie – used two 160kW flywheels and up to 240kW of batteries. It demonstrated the rapid frequency response and voltage control capabilities of the system, and its flexibility to be 'tuned' to different event needs. The project was the first field test of a hybrid-flywheel energy storage system in Europe and was funded by a £2.55 million grant from the European Commission. Irish transmission system operator (TSO) EirGrid and Schwundgrad developed control algorithms for the plant, which were tested in response to real-time frequency events. However, because the project was at demonstration-scale (300kW), the potential for balancing (energy) services was not tested, and voltage support services were not tested because the plant was embedded in the distribution system. eNeRGY STORAGe