Excellent network management

Supply reliability of the electricity grid

Our customers were without electricity for an average of 23.2 minutes (2019: 21.9 minutes), which is more than the target of 23 minutes. As in 2019, no major outages occurred. However, there were more medium-voltage outages during the hot summer, leading to an increase in outage duration compared to the previous year. This was caused by weak components in the grid overheating and failing. In 2020, 33% of the annual outage duration was caused by external factors, up from 27% in 2019. Damage caused during excavation work by third parties is another major cause.
We measure the number of repeat outages by analysing which cables are associated with five or more outages. The cables in the power grid are numbered. The number of unique cable numbers in the power grid associated with more than five repeat outages per year was 17 (2019: 17). This was on target.

Power grid outage duration and causes
  • 1 The Dutch average for 2020 is not yet known.
Repeat outages

Supply reliability of the gas grid

Gas outages are relatively uncommon. The main cause of fluctuations in the gas outage duration are random outages caused by a third party and which leave customers without gas for a long time. In 2020, the outage duration on the gas grid was 83 seconds. The outage duration is mainly attributable to a major breakdown in Zaandam on 27 January 2020 (shown in the diagram under ‘other’). If this breakdown had not occurred, the average outage time on the gas grid would have been just 30 seconds. 

Outage duration of gas grid and causes
  • 1 The Dutch average for 2020 is not yet known.

Infrastructure maintenance

In 2020, we spent €1,030 million on the maintenance, replacement and construction of our energy infrastructure (2019: €1,044 million). Infrastructure maintenance takes place at various locations throughout the year. Last year, we found that switching off the power to get the work done caused more problems than normal. More customers are working at home due to the COVID-19 crisis. In some locations, residents even tried to stop our technicians carrying out their work. We at Alliander find this behaviour unacceptable, so we continue to explain why it is important for our people to stay on the job and ask the public to maintain the recommended social distance.

Replacement of grey cast-iron and asbestos cement mains

Since 2009, a large-scale replacement programme for the replacement of grey cast-iron and asbestos cement mains has been under way. Together with municipalities, contractors, suppliers of materials and excavation contractors, we have identified opportunities for accelerating the work, where possible in combination with the heating transition. The new completion date when all the mains in the scope of the remediation plan will have been replaced is now 2032 instead of 2040. 
In addition to accelerating the activity, we have also agreed to intensify the frequency of gas leak detection in the pipelines. Gas leaks can lead to benzene contamination. Studies indicate that contamination incidents do not lead to risks for the employees who repair the gas leaks nor for those in the vicinity of the gas escape. Nevertheless, our aim is to detect gas leaks before they become a problem. We use extremely sensitive equipment for this, which is capable of detecting minimal gas leaks at a very early stage. The search frequency was increased last year to once a year instead of once every five years.

Access to energy

Prepaid energy

For some customers, paying their monthly energy bill is quite a struggle. Liander also has to find solutions each year for customers who do not have an energy contract with an energy supplier. We applaud social initiatives in the area of energy awareness, such as the Energiebank [Energy Bank] and the Prepaid Energy Service pilot project, and participate in these initiatives to help people on a low income stay out of debt and ensure that they can arrange and maintain adequate access to energy. 

Disconnection as a last resort

We prefer not to disconnect customers’ power in the winter. In this context, we go further than the law requires. The law states that we must stop disconnecting customers if it freezes in De Bilt (the site of the Royal Netherlands Meteorological Institute) for 48 hours. Every week, we take a look ahead to determine whether the average temperature will be below zero in any 24-hour period. In cases of doubt, we decide in the customer’s favour.

Performance in the regions

A great deal of work is being done in Liander’s service areas to make the energy network ready for the future. The ambitions and activities differ from area to area. Liander helped prepare the draft Regional Energy Strategies that were submitted in June. We participated in various working groups and forms of administrative consultation. We drew up grid impact reports to quantify the impact of the draft Regional Energy Strategies on the power grid and outlined how to organise local supply in the most system-efficient way. We also supported municipalities in their work to prepare the Transition Vision Statements for Heating.  


In the province of Noord-Holland, the demand for electricity continues to grow, but the capacity of the network is not always sufficient. To help resolve this situation, Liander collaborated with TenneT in various power grid expansion projects in 2020. For example, the substation in Haarlem Schalkwijk was partially renewed. In Haarlemmermeer we expanded the electricity grid to facilitate the connection of data centres. As part of this work, we built the 20kV section at the Vijfhuizen electricity substation. We also started a feasibility study to find the best location for a new substation at the Schiphol Logistics Park in Rozenburg.

Despite all these expansion projects, the growing demand for power is still causing capacity shortages in various places in Noord-Holland. In the northern tip of Noord-Holland, this restricts the amount of energy that can be fed back into the grid. The Wieringermeer wind farm was however successfully put into service. Liander laid 20kV connections between the wind farm and the newly constructed Middenmeer substation in order to connect up the turbines. In the Haarlemmermeer and Zaanstreek areas, grid restrictions stand in the way of new and additional power. Consequently, work will also continue in future years in order to expand the network.


To emerge sustainably from the COVID-19 crisis, Amsterdam is investing tens of millions in measures that will help create jobs and make the city more sustainable. This includes making homes natural gas-free and installing solar panels on housing corporation properties. We are investigating the impact of this on our infrastructure and trying to create an optimum overlap between this schedule and the capacity enlargement and replacement plans for our cables and pipes. In addition, we are working with the municipality to retrain people who have lost their jobs due to the COVID-19 crisis in order to fill technical vacancies.

At the same time, growth in the Dutch capital and initiatives to make it more sustainable will lead to a major increase in the capacity needed in the power grid. Liander is working with the municipality and TenneT to create the future power grid for the city: we are upgrading the power grid infrastructure in several places. For example, we are increasing capacity at stations in Nieuwe Meer and Bijlmer-Noord. We are also talking with the municipality about building new stations at various locations in the city, such as IJburg, the Havengebied, Amsterdam Zuid-Oost and Amsterdam Noord. Preparations for tackling the Venserweg substation have started. Liander has also replaced more than 33 kilometres of obsolete gas pipes to prevent leakages. 


The number of solar roofs and solar farms in particular is growing rapidly in Friesland. This development is putting increasing pressure on the power grid. The provincial authority has announced solar energy policies that are designed to limit the emergence of large-scale solar farms. Liander collaborated with TenneT where necessary to resolve bottlenecks. For example, we completed the capacity upgrade at the Dokkum substation. The enlarged Wolvega substation was also completed. We are currently involved in permit procedures for a new electricity cable to Ameland. Preparations for expanding the Oudehaske substation also started in 2020. We have made good progress in expanding the Oosterwolde substation, which will be ready in 2022, and with the preparations for the Bolsward substation. The latter substation will be used for the wind farms near the Afsluitdijk and is expected to be completed in 2023.


The province of Gelderland covers a large and diverse area that is increasingly characterised by initiatives for large-scale generation of wind and solar energy, natural gas-free districts and transport electrification. These trends, together with the development of business parks, logistics centres, the greenhouse horticulture sector and new housing construction, mean that the demand for electricity is growing and sometimes exceeds the capacity of the grid. To help resolve this situation, Liander also worked on expanding the power grid in 2020. In the Rivierenland region, we are expanding existing stations and looking for suitable locations for new stations together with TenneT. In Neerijnen, we were the first regional network operator to start congestion management; a novel approach that shares limited capacity on the power grid. In addition to the expansion projects at the Ulft and Borculo substations, we worked hard on upgrading the local grids in the Achterhoek area. The aim here is to facilitate the large number of applications for solar power generation. We are building a new substation in Oosterhout to meet the rapidly growing demand for power in Nijmegen-Noord. And, in order to supply power to more customers in the meantime, we are laying extra cables from the Park 15 business estate to the Bemmel substation. A large conversion project is also ongoing at the Barneveld substation.
Together with Overijssel, the provincial authority of Gelderland has drawn up a regional strategy for rolling out charging infrastructure for electric vehicles. A total of 246 new electric buses have been taken into use for bus services in the Veluwe and Midden-Overijssel regions. Liander completed the necessary grid expansions and provided the connections required to facilitate the charging infrastructure for these buses.


During the past 18 months, the rapid growth in solar power generation in Flevoland caused bottlenecks in the power grid in many places. The main issue in the Noordoostpolder is a shortage of transmission capacity for all the solar energy that is being fed back into the grid. In order to solve bottlenecks, we are working on various expansion projects and upgrades, including construction of a substation in Dronten. We have started expanding our power grid for the Noordoostpolder and Urk. In addition, two new substations are being built to significantly increase capacity, particularly in Urk. This project is expected to take four to five years to complete. The preparations have now started. In Zeewolde, the first green gas booster has now been installed and connected to the regional gas grid. The booster raises the pressure of the green gas from four bars to the eight bars required in the gas grid. Thanks to the new compressor, producers can feed green gas into the grid throughout the year.


There is an increasing demand for electricity in Zuid-Holland. We are adapting the infrastructure accordingly in consultation with the regional authorities. In 2020, the first steps were taken in preparation for a substantial investment programme designed to upgrade the region’s power grid in line with the high level of demand for electricity. Together with TenneT, the municipalities of Zoeterwoude, Leiden, Voorschoten, Leiderdorp and the provincial authority, we started looking for a location for a 150kV power station in the Leiden area, and a further four 50kV stations. In addition, we are also collaborating with Stedin and TenneT to develop and construct a completely new station in Zuidplaspolder. In Boskoop, work has started on expanding the power grid so that it can keep up with rising demand for energy in the area. 

As part of the local energy transition programmes, we have built new medium-voltage transformer stations and connected charging points. Agreements have been reached with municipalities about upgrading natural gas pipes and the first pipes have been replaced. We are also actively involved in the regional strategy for charging infrastructure: Regionale Aanpak Laadinfrastructuur (RAL).

Investments by region


Investments (in millions of €)













Other (Kenter and Alliander AG in particular)