ENTSO-E HVDC Utilisation and Unavailability Statistics 2020 Publication Date: 24 June 2021 System Operations Committee European Network of Transmission System Operators for Electricity ENTSO-E HVDC Utilisation and Unavailability Statistics 2020 Copyright © 2021 ENTSO-E AISBL Report rendered 28 June 2021 European Network of Transmission System Operators for Electricity Executive Summary The HVDC links are important components for a stable op- The most utilised electricity market connection was the one eration of the Nordic and Baltic power system while sup- between Finland and Sweden (FI–SE3, HVDC links Fenno- porting the commercial power trade in the European energy Skan 1 and 2), with 85 % of the technical capacity being used markets. Furthermore, the HVDC links can provide other for transmission, as shown in Table ES.1. No other market important functions like voltage and emergency power sup- connection reached such a high utilisation percentage, and port to the HVAC grid. Hence, the advantages of keeping only seven of the thirteen market connections showed a util- the HVDC links in operation as much as possible are indis- isation percentage of more than 60 %. However, the utili- putable. The ENTSO-E HVDC Utilisation and Unavailabil- sation percentage of all HVDC links in 2020 was still at its ity Statistics 2020 report aims to provide an overview of the all-time highest value since 2012. The market connections Nordic and Baltic HVDC links as well as a detailed view of with most unavailability were the ones between Denmark each individual link. The executive summary concludes the and Netherlands (DK1–NL, HVDC link COBRAcable) and most important parts of the report into one chapter. Denmark and Germany (DK2–DE, HVDC link Kontek), with 29 % and 30 % of the total capacity being unavailable due to Overview outages and limitations, respectively. In 2020, 58.8 TWh of electric energy was transmitted through Table ES.1: Annual utilisation rate of HVDC links per bidding zone. the Nordic and Baltic HVDC links, which is approximately 2012 2013 2014 2015 2016 2017 2018 2019 2020 DK1–DK2 45% 54% 58% 70% 78% 64% 63% 58% 71% 62 % of the total technical capacity (Emax) and correlates well 80% 51% with the percentage utilisation from previous years. Never- DK1–NL DK2–DE 70% 70% 73% 75% 67% 66% 53% 69% 47% theless, the transmitted energy and unavailable technical ca- FI–EE 59% 55% 41% 57% 42% 29% 37% 47% 75% pacity is showing a slight increasing trend after a significant FI–SE3 54% 53% 76% 76% 78% 70% 72% 81% 85% drop in 2012 and 2013, as seen in Figure ES.1. LT–PL 34% 47% 54% 61% 58% % Tecnhical capacity not used NO2–DK1 68% 61% 55% 54% 61% 54% 53% 46% 62% Annual utilisation of all HVDC links % Transmission NO2–NL 89% 72% 90% 94% 72% 83% 68% 61% 77% % Unavailable technical capacity 69 TWh 69 TWh 75 TWh 80 TWh 89 TWh 89 TWh 89 TWh 90 TWh 95 TWh RU–FI 34% 36% 25% 29% 46% 50% 67% 61% 23% 100% ) Eₘₐₓ ₓ SE3–DK1 56% 40% 49% 49% 59% 52% 53% 50% 57% ₐ ₘ 24% E ( 31% SE4–DE 60% 32% 47% 31% 43% 46% 33% 36% 55% 33% 37% 35% 35% 35% 33% y 80% 40% t i c SE4–LT 44% 51% 50% 63% 76% a p a c SE4–PL 52% 34% 61% 67% 56% 62% 66% 62% 72% l 60% a c i n Grand Total 57% 50% 56% 58% 57% 56% 57% 58% 62% h 62% c e 58% t 40% 57% 57% l 50% 56% 58% 57% 56% a t o t f The most significant unavailabilities in 2020 occurred for o 20% % Baltic Cable, COBRAcable, Kontek, Konti-Skan 2, NorNed 14% 0% 10% 10% 7% 7% 8% 9% 10% 11% and Skagerrak 1–4. Baltic Cable had 1 more severe distur- 2012 2013 2014 2015 2016 2017 2018 2019 2020 bance outage, which was caused by a fault on the DC sub- Figure ES.1: The annual utilisation of all HVDC links since 2012. marine cable, probably cut by an anchor of a boat, and lasted Technical capacity not used is the amount of energy that has nei- 29 days. The limitations on Baltic Cable were mainly due ther been transmitted nor been unavailable due to limitations or to maintenance in the AC grid. COBRAcable’s unavailabil- outages. ity was mainly due to a disturbance outage caused by a sub- The total number of disturbance outages registered was 51, marine cable fault in September and lasted until 8 January preventing 4.1 TWh of potential energy transmission, or 2021. Kontek had a fault on the land cable on the German 4.3 % of the total technical capacity (Emax). Maintenance out- side, which resulted in 94 days of further unplanned main- ages amounted to 4.8 TWh, or 5.0 % of the total technical ca- tenance shortly after the 18 day long annual maintenance in pacity (Emax), and limitations reduced the transmission ca- September. Konti-Skan 2 (and 1) limitations where mainly pacity by 4.0 TWh (4.2 % of the total technical HVDC trans- due to maintenances on the AC-grid on both the Danish and mission capacity). The amount of unavailable technical ca- Swedish side. The disturbance outage on Konti-Skan 2 was pacity compared to the total technical capacity (Emax) has due to a fault in the smoothing reactor. increased by approximately 1 % per year since 2015 and was NorNed’s planned maintenance outages and limitations in 2020 at its highest point since 2012, as can be seen from were due to AC filters problems in Holland. The limitations Figure ES.1. The increasing trend is visible in all unavailabil- were also due to the AC filters. Both Skagerrak 1 and 2 had a ity categories except other outages. The unavailable techni- long disturbance outage caused by a cable fault due to (dif- cal capacity includes disturbance outages, limitations, un- ferent) ships. Skagerrak 4 had an additional planned mainte- planned and planned maintenance outages and other out- nance outage from May to July to cut cable samples for tests ages. ENTSO-E HVDC Utilisation and Unavailability Statistics 2020 | i European Network of Transmission System Operators for Electricity and investigations. Skagerrak 1, 2, 3 and 4 have been limited mission as in 2012 when approximately 59 % of the technical due to “careful operation” since the Skagerrak 4 cable faults capacity (Emax) was utilised. The remarkable increase also in December 2019. In 2020, the north direction (DK1→NO2) applies to EstLink 2, where 85 % of the technical capacity was prioritised until March, after which the south direction (Emax) was utilised as transmission. EstLink 2’s utilisation (NO2→DK1) was prioritised. The effect of these incidents can was the second highest of all HVDC links in this report in be seen in Figure ES.2. 2020, while at the same time reaching its all-time high value Unavailability percentage for each HVDC link in 2020 since its commissioning in 2014. The technical capacity not used was 40 % of the technical capacity (Emax) for EstLink 1 Baltic Cable 18.7% and 12 % for EstLink 2. COBRAcable 29.3% 3.0% EstLink 1 Unavailable technical capacity (EU) due to outages and limi- EstLink 2 2.5% tations reached approximately 3 % for both EstLink 1 and 2. Fenno-Skan 1 1.6% Fenno-Skan 2 0.5% Also, approximately 3 % of all operating hours were affected Kontek 30.0% by outages or limitations for both EstLink 1 and EstLink 2, Konti-Skan 1 14.0% which means that nearly all of the outages and limitations Konti-Skan 2 19.2% reduced the transmission capacity by 100 % when they oc- LitPol Link 8.6% curred. NordBalt 5.5% NorNed 16.9% Fenno-Skan 1 and 2 Skagerrak 1 33.9% Skagerrak 2 44.2% The use of Fenno-Skan 1 continued to be very high in 2020, Skagerrak 3 17.1% with 97 % of the technical capacity (Emax) being utilised Skagerrak 4 17.3% for transmission. On the other hand, the utilisation rate of Storebaelt 0.3% Fenno-Skan 2 was 78 % of the maximum technical capacity SwePol 12.8% Vyborg Link 11.5% (Emax) leaving approximately 21 % of the technical capacity Grand Total 13.5% unused (ETCNU). The technical capacity not usedTCNU (E ) of 0% 10% 20% 30% 40% 50% Fenno-Skan 2 increased slightly (by 1 percentage point) com- pared to 2019 (20 %), but was still only approximately half of % of total technical capacity (Eₘₐₓ) the respective values in 2017 (40 %) and 2018 (39 %). Fenno- Figure ES.2: Percentage of unavailable technical capacity due to limitations, disturbance outages, unplanned and planned mainte- Skan 1 was the most utilised HVDC link in 2020 in this report, nance and other outages for each link in 2020. and Fenno-Skan 2 was the third most utilised HVDC link. Almost all of the transmitted energy of Fenno-Skan 1 and Individual HVDC links 2 was transmitted from Sweden to Finland (SE3→FI) via Fenno-Skan 1 and 2. Both links had 4 planned maintenance Baltic Cable outages each, and Fenno-Skan 1 had 3 minor disturbance Baltic Cable had in 2020 its highest utilisation percentage of outages. The average number of outages since 2017 is lower 55 % of the maximum technical capacity (Emax) since 2013. than the corresponding value for 2012–2016. Totally, below However, a fifth of the maximum technical capacity was un- 1 % of the maximum technical capacity was unavailable (EU) available. The unavailability was mainly due to one distur- due to outages and limitations in 2020.