May 2016 marked a milestone for Energias de Portugal (EDP) as the entire country kept its lights on for four consecutive days using only electricity generated by wind, hydraulic, biomass and solar power. This was apparently a first in Europe, if not the world, in terms of number of consecutive days of production and distribution of ‘clean’ energy alone.
Yet relying more on renewables has been only one of EDP’s major goals in recent years. Another has been responding as quickly as possible to power interruptions from events such as recurring winter storms, frequent fog and interaction with lines by trees and large populations of protected birds – all of which adversely impact reliability. For example, one particularly heavy storm in January 2013 caused outages that affected over a million customers, some for several days.
INMR Contributor and T&D Insulation Coordination Specialist, Raouf Znaidi, met management and engineering staff at EDP Distribuição (EDPD) in 2016 to report on how the Portuguese DSO has been dealing with these and other challenges.
EDP is the largest electricity producer and distributor in Portugal, with a generating capacity of more than 24,000 MW and serving more than 6 million customers. EDPD Executive Board Member, Ângelo Manuel Sarmento, says that Portugal has considerable renewable energy resources of which wind and hydropower are the most cost-effective. Priority has therefore been placed on exploiting the two. Indeed, these sources now account for 33% and 24% respectively of total power generated, ranking EDP among the top ‘clean energy’ suppliers not only in Europe but also in the world
Moreover, when it comes to new investment in green energy, EDP has been closely involved in R&D that relies on floating offshore platform technology, which is claimed to offer significant advantages over wind power solutions based on the seabed. This has positioned the country and its supply partners at the forefront of ‘renewables’ technology. Given these types of initiatives, in 2015 EDP committed to increased green energy generation such that it will exceed 75% of total installed capacity by 2020. This is expected to reduce CO2 emissions from their 2005 baseline level by this same proportion before 2030.
EDPD operates and maintains 81,694 km of lines and cable from 6 kV to 60 kV, with about 80% of the network being overhead. There are 416 substations, 120 switching substations and over 66,000 secondary substations.
Typical Portuguese weather is characterized by an oceanic climate in the north and a Mediterranean climate in the south. For example, average annual rainfall varies from less than 600 mm in southern areas to over 3,200 mm in the northern mountains. In addition, there is high risk of heavy winds, sometimes exceeding 130 km/h. Moreover, western and southern coastlines total nearly 1,000 km and the country the highest proportion of forested area in Europe – some 38% – mostly maritime pine, eucalyptus and protected cork oak.
EDPD’s Maintenance Director reports that one of the greatest operating challenges is ensuring reliability in wooded areas during periods of heavy rain combined with strong wind. The forest soil becomes highly wetted and bogged down, which increases risk of trees being uprooted – especially species with superficial roots such as pine and eucalyptus that are abundant along 15 kV, 30 kV and 60 kV line corridors.
In addition to dealing with reliability challenges from this difficult service environment, EDPD has also begun developing an Asset Management System based on risk, supported by a corporate project called JUMP, and as described in ISO 55000. These efforts are similar to what was done when being certified for Management of R&D and Innovation in accordance with NP4457 and also for the Environmental Management System as per ISO 14001.