Challenge
This challenge addresses the needs described below:
- How can we make predictions that plan for and quantify climate-related risks?
- How can we reduce to a minimum the damage caused to grid assets due to falling trees or branches near electrical distribution lines?
- How could IBERDROLA optimise decision-making when making investments in the distribution grid, be it through considerations related to the easement strip or other alternatives?
Background
The electrical system is the backbone of modern society. Basically, it is the sector on which almost all other sectors depend for their routine operation. This is especially true for Europe, which possibly has the world's most complex electrical grid, comprised of thousands of generating stations, hundreds of thousands of substations and more than 5 million kilometres of lines, operating across the continent. In addition, the electrical grid is tasked with maintaining its operations almost 100% of the time, even in conditions of extreme weather, fuel shortages, direct attacks and human errors.
Likewise, the necessary decarbonisation of our society involves, on the one hand, the “electrification” of many energy-consuming sectors, and on the other the integration of renewable distributed generation technologies that increasingly require a stable, robust and at the same time, flexible, operation of the electrical grid.
In order for the electrical system to operate efficiently and reliably, it must maintain the continuous operation of its four key elements: generation; transmission; distribution and demand. However, the distribution grid, due to its size and new environmental threats due to climate change, requires increasingly higher investments that improve its resilience in preparation for these challenges.
The historical data show that some of the distribution grid outages in forest environments are due to falling trees and branches on the power lines, both inside and outside the easement area of the lines.
These falls do not have a single cause, but rather in general they are due to an accumulation of them (wind, snow, pests, ground erosion, etc.); however, they all seem to become more frequent with the increase in extraordinary weather phenomena associated with climate change (strong storms, extreme heat waves, etc.).
As for the vegetation in the easement area of the electrical power lines, the current felling and pruning process is highly digitalised and industrialised. During the management of the vegetation prior visits are carried out to the work areas travelling along the electrical power lines (even carrying out flights with helicopters). On these visits, diseased trees or those which due to their inclination present a risk of falling on the power lines are identified within the easement area, and are cut down to eliminate the risk. However, electrical distribution companies cannot act outside these areas and this management does not take into account the above-mentioned extreme weather conditions associated with climate change, which are increasingly frequent and of higher intensity, making it more difficult to identify the trees at risk of falling.
Therefore, in order to determine the risks and threats of interruptions in the distribution grid caused by events associated with extreme climate phenomena or environmental conditions, and to evaluate investments that could reduce these risks, we must take into account the following primary environmental factors: wind, density of vegetation, structure of the ground (for example, plasticity as a result of humidity, slope, composition of the ground/horizons, roots and deep waterlogging of the ground), load on the trees (due to ice/snow, etc.) and their long-term evolution due to climate change.