Over the 23 years of INMR’s existence, there have been several tendencies when it comes to R&D for electrical power systems. A first phase, during the 1990s, focused on product innovation and examples are composite insulators and zinc oxide arresters. A second phase, starting at the turn of the century, was marked by development of UHV transmission. Lately, there is an emerging third phase that devotes growing attention to technical as well as environmental optimization. There are widespread efforts to make systems more ‘intelligent’ and, in the process, also increase reliability through more detailed and accurate information. In particular, data on weather and climate patterns are emerging as critical not only to plan and optimize generation and revenues of conventional and renewable sources but also to assure system reliability as well as safety of personnel. For example, severe weather events are the most common cause of outages and, in cases such as live line maintenance, can also create safety risks. Moreover, line and substation insulators are among the components most affected due to their combined electrical and mechanical functions. Two distinct aspects have to be considered in regard to weather parameters: the impact on day-to-day operations and long-term trends related to the climate change.
Current Weather & Short-Term Forecasting
Historically, whenever an electrical utility wanted to predict events such as lightning, managers kept an eye turned to the sky. Today, with the help of satellite technology and lightning detection systems together with advanced modeling, ‘now-casting’ and even predicting weather for a few days is very accurate. Such improvements in predicting severe weather such as hurricanes, winter storms and major thunderstorms aid utility management to deploy crews and equipment close to areas where damage is likely, thereby helping restore power quickly. Having advance warning of possible lightning activity and other such events also helps utilities protect crews from hazardous working conditions. In addition, accurate location of strokes, together with information on magnitude of related current, helps to better categorize faults due to lightning. Moreover, detailed local information on parameters such as wind, wetting events and temperature can help the causes of faults not related to lightning be better understood. This forms the basis for deciding on suitable countermeasures aimed at improving reliability, e.g. by cleaning or otherwise refurbishing insulators.
Climate Change & Power System Design
Design of electrical systems is typically made looking at historic data in order to generate a prediction of likely service stresses on components such as insulators. However, nowadays such an approach is questionable. The Assessment Report of the International Protocol on Climate Change concluded that considerable climate change is now unavoidable, even if aggressive curbs on greenhouse gas emissions are put in place. There is still a great deal of uncertainly regarding the nature, magnitude and frequency of extreme weather as climate change unfolds. But many studies indicate increasing frequency and intensity of such events in most places, with obvious potential threat to energy infrastructure. For example, models predict substantial warming in temperature extremes by the end of this century, increased frequency of heavy precipitation or proportion of total rainfall from heavy falls, and increased maximum wind speeds from tropical cyclones, although not necessarily in all ocean basins.
The importance and timeliness of these issues is demonstrated by the special IPCC report, Managing the Risks of Extreme Events to Advance Climate Change Adaptation. Globally, tens of trillions of dollars will have to be invested in energy systems over coming decades and many new installations will be exposed to significantly changing weather patterns over their multi-decade lifetimes. Use of present-day and historic weather and seasonal climate data is presently part of everyday risk management by utilities and regulators across the globe. However, in view of the above, integration of forward-looking information on changing climate when making design and operational decisions has become much more important.