Climate

To ensure Stockholm Royal Seaport achieves its goal of becoming a fossil-free and climate-positive district by 2030, energy usage and climate impact need to be minimised. According to a 2023 residents’ survey, the most important issue for the residents of Stockholm Royal Seaport is reducing climate impact and using energy efficiently.

2023 Highlights:

Fossil-free energy system

By setting technology-neutral requirements, developers are free to choose energy supply. Four out of five developers prefer to connect to the existing district heating system, while others have chosen heat pumps powered by environmentally labelled electricity. Stockholm’s district heating system is well-developed, with half being renewable energy. District heating is produced from renewable or recycled energy sources. Waste used for energy production contains fossil material, which will be offset by the negative emissions from the bio-CCS facility Stockholm Exergi plans to build in Energihamnen.

To promote local production of renewable energy, buildings in the area are required to generate at least 2 kWh/m² A_temp of solar energy. Monitoring shows that residential buildings generate an average of 3.2 kWh/m² and commercial premises 3.3 kWh/m². To date, 644 MWh of solar energy has been produced in the completed phases. 235 MWh and 37 MWh of solar energy have been produced at the the and centres, respectively.

According to the 2023 residents’ survey, 30 per cent of households have contracts for environmentally certified electricity.

An investigation is underway to determine whether a fossil-free energy system can be achieved by optimising energy production and usage at the district level, for example, by harnessing residual heat from the wastewater system and increasing the proportion of locally produced solar energy.

Fossil-free transports and construction machinery

To achieve fossil-free passenger and freight transport, vehicles need to be powered by electricity or renewable fuels. Regional and national policy instruments are required to achieve this goal. Developers are required to build charging infrastructure in garages to encourage residents to use electric cars. Currently, 16 per cent of car parking spaces in garages are equipped with charging stations, and all carpool parking spaces on street level have charging facilities. As electric car ownership has increased from 17 per cent in 2019 to 32 per cent in 2023, the requirement for the proportion of charging stations has been adjusted from 20 per cent to 50 per cent for upcoming land allocations. In an external and shared parking garage, Hjorthagsgaraget, all parking spaces will have charging facilities. Additionally, a pilot project to introduce Environmental Zone 3 in Stockholm is underway. The feasibility of implementing this in Stockholm Royal Seaport will be evaluated.

The development of Stockholm Royal Seaport generates a large number of heavy transports and the use of heavy machinery. Since a significant portion of traditional fuel is fossil-based, requirements are set for the use of renewable fuels. To support contractors in the transition to fossil-free fuels, two fuelling stations providing renewable diesel, HVO100, have been opened in the area. The stations are also open to the public. In 2023, 68 per cent of all fuel used in the City’s construction of public space was renewable, mainly HVO100. Furthermore, 100 per cent of electricity used at construction sites is renewable.

As part of efforts to achieve the transition to zero-emission transport, (which does not emit carbon dioxide during operation), two electric trucks have been procured. Electric construction machinery is not yet widely available on the market. The City of Stockholm is developing a strategy for how incentives can be created to encourage the use of electric vehicles and construction machinery. The strategy will also include mapping future power needs and charging infrastructure. Projects are currently underway to identify and examine user patterns and factors relating to electric trucks, energy storage systems, and solar panels.

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Low climate impact from embedded materials

The construction of new buildings and facilities involves significant climate impact due to the production of materials and from the construction process as a whole. To minimise climate impact, measures must be taken in the design and construction phases.

The construction of a building contributes to more climate impact than the energy use in that building over a 50-year period. With Stockholm Royal Seaport’s energy requirements and Stockholm’s district heating mix, the construction phase accounts for about 70 per cent of buildings’ total climate impact. Since 2016, developers have been required to conduct climate calculations in design and construction phases. Climate calculations must be supplemented with analyses and action plans that includes measures to reduce climate impact. Three developers have reported their first climate calculations for design phases; these average around 240 kg CO2 per m².

In upcoming land allocations there will be requirements with threshold values that will gradually be reduced to 180 kg CO2e per m² by the year 2030.

To better understand the climate impact from different parts of a detailed development plan, comprehensive climate analyses have been conducted for the Kolkajen and Valparaiso phases. The analyses form the basis for identifying which parts of the infrastructure contribute to significant climate impact and subsequently identify solutions to address these impacts.

The planned Kolkajen development will partly be on an extension into the water, with the quay line being extended to create new land, thereby creating the most significant climate impact of the project. The remediation and stabilisation of the existing quay will also result in significant impacts. Changes to how these foundations are laid and the method of land reclamation has been reduced climate impact by 60 per cent.

Streets in the Valparaiso area need to be built on bridges to connect to existing buildings. Preliminary climate analysis of the detailed development plan shows that planned bridge construction considers climate impacts. Efforts to minimise the climate impact of infrastructure in the area will continue.

Climate calculations from four completed detailed development plans have been conducted to gain further knowledge regarding the climate impact from the construction of public spaces. These are based on data on soil remediation, foundations, construction roads, parks and other public spaces as well as measured amounts of energy for construction machinery and transport in Stockholm Royal Seaport. Results vary from just over 50 kg CO₂/m² of public space in Brofästet to more than 580 kg CO₂/m² in Västra. The difference between the two numbers is due to the need for soil reinforcement measures in Västra, which is built on former seabed. Calculations also show that in all four cases, the amount of cement-based and steel products has a significant climate impact and that construction sites’ energy use and transport of masses and building materials account for a smaller proportion of climate impact.

In addition to measures being taken in design phases to reduce climate impact with optimised construction and solutions, requirements are set in terms of reinforcing steel, asphalt, and concrete in all contracts. Moreover, development work is ongoing in which slag is being tested in concrete. So far, three full-scale tests have been conducted, including in underwater concrete.

Biochar is used to improve soil quality in most of the street plantings in the area. Planting substrates, the material in which plants grow, contain a mix of biochar and gravel. To date, the use of biochar in Stockholm Royal Seaport has contributed to a temporary carbon sink effect of 5,400 tonnes of CO₂.

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