White electric car in Stockholm at charging station with blue plug

Grid Capacity Challenges in Sweden

Against a backdrop growing concern over climate change, COP25 is taking place in Madrid in early December 2019. Decarbonisation of the whole economy is rising higher up the political agenda. Net zero targets are being set by more and more countries and are discussed now at a European level. The 1.5C ambition already targeted in the Paris Agreement translates for Europe to a 95% economy-wide decarbonisation target. Whether 95% reduction or net zero by 2050 (or earlier) what is clear is that the building renewables in electricity sector will not solve the challenge alone. Decarbonising the whole economy means more than just building wind farms. But even if we can build low cost wind farms – we still need to transport the electricity they produce to the end consumers.

In this article we focus in on one area that creates a barrier to economy-wide decarbonisation – that of grid constraints – and we focus in on the situation in Sweden which faces a particular set of challenges.

Sweden is growing and things are moving fast. Traditional industry is being renewed, and growth in robots, cloud services, artificial intelligence (AI) and other digitalization phenomena are leading to a strong increase in the demand for power. At the same time, utilisation of the once well-dimensioned electricity grids is reaching unprecedented levels. As a result, providing grid access for new users and connections is no longer straightforward. Adding to the challenges, several large grid development projects have lingered for years in complex concession processes, for as long as 15 years.

AFRY在2018年进行的一项研究显示了戏剧性的我mplications of grid capacity restraints; if the situation is not improved, as much as 16 GW of new connection,s representing an annual socio-economic value 150 billion SEK, may be lost by 2030. Already today, the estimated socio-economic cost of insufficient grid capacity is as high as 80 billion SEK per year, not counting indirect effects. By comparison, the value of the full, Swedish electricity network is 170 billion SEK.

The lack of capacity hurts economic development, especially in southern and mid Sweden, by limiting electrification of transport, establishment of new companies, development of new urban areas, business and residential buildings. In particular, lack of grid capacity limits regional development in the larger urban areas like Stockholm, Gothenburg and Malmö.

不缺发电,问题是输电和电网容量。不断增长的需求被增加的发电量所平衡,尤其是风力发电厂的发电量。然而,大部分新增风电容量在北部,而南部老化的核电站将从今年和明年开始逐步淘汰一个区块,用于Ringhals 2和Ringhals 1。从北到南的大型电力线不能完全吸收这一变化,瑞典南北之间的输电能力(NTC)将在更大程度上成为一个瓶颈。目前最大功率为7000兆瓦NTC。南方的风力发电量相对较少,不足以弥补可预见的强劲需求增长。在低风运行时间,瑞典南部依赖邻国的净进口能源。这一赤字将进一步加剧,需要更多的交换容量、更多的发电机容量或两者兼而有之。400千伏电网主干网压力的增加意味着未来几年的运营利润将减少。在高传输时间,系统将更容易出现故障。这些时间内的故障更难缓解。总之,现有电网的过度利用将对系统的可靠性产生影响,但很难用多大程度来量化。

为了解决能力不足的问题,需要采取多种措施和行动。虽然建设更多的电网容量是一项高度优先的行动,也是最终的解决方案,但更好地利用现有的通行权,结合需求方的灵活性,提供了一套不同的工具来管理危机:对于后者,关键问题是如何以最小的社会经济成本调整需求,以及如何创造有效的市场来确保这一点的实现。就前者而言,现行的路权和现有电网使用规则可能会改变,以提高利用率。随着对灵活性的更好的市场设计和对电网替代品(如电网规模的电池存储)的更简单、有针对性的投资,这两个系列措施至少可以缓解部分容量限制。显然需要权衡选定可靠性水平的社会经济成本与严重电网容量限制的社会经济成本。

加快电网让步和建筑业

Democratic processes take time. While a fundamental and highly-valued part of our democracy, streamlining concession and investment processes will be necessary in order to catch up with the current backlog in grid capacity. This is especially true for transmission grids, where lead times for construction regularly exceed ten years. At the same time, insufficient communication and coordination between stakeholders aggravate the challenges and the time spent on decision processes. Enhanced planning and coordination processes should be introduced as to ensure that all important elements in understanding the future need for capacity are properly dealt with. Better coordination not only contributes to better investment decisions, it also clarifies “the good story” to the wider public and strengthens public acceptance of new capacity projects.

经济激励和融资也是重要因素。在即将到来的监管时期,许多大型电网业主将被要求降低电价,从而降低收入。降低电价有利于保护消费者;然而,降低电价也可能导致电网投资减少。

Finally, both organisation and capacity of public bodies could be strengthened and improved. Instead of sequential proceedings, parallel processes across different public bodies should be developed where possible. Staffing in relevant bodies and offices should also be increased as to avoid unnecessary delays in public proceedings.

Demand side management (DSM)

DSM can be defined as an array of activities to alter utilities’ load shape and/or energy consumption patterns. It can be utilised to shift part of the electricity demand from peak demand hours or unfavourable electricity generation hours, to valley hours or favourable electricity generation hours. The fundamental idea is to guarantee that demand and production are continuously being balanced, whilst reducing the stress on the transmission and distribution lines.

The incorporation of DSM into the electricity market has been made possible through technological advancement in communication and the rollout of smart meters. Its implementation in the electricity market can be facilitated, amongst other strategies, by load-based time varying grid tariffs. These could be employed in order to reflect the necessity of decreasing load by showcasing high prices, or, conversely, to incite power consumption by exhibiting low prices. More advanced, dynamic grid tariff models may be much more targeted at resolving acute congestion and capacity constraints. However, our studies on end user behaviour and preferences clearly show that end users are unlikely to accept and react to complicated, dynamic pricing models unless combined with automated load and energy management systems. In consequence, third party players like energy service companies (ESCOs) are crucial in order to help end users utilise their available flexibility. New business models require a financial basis: This could be realised either directly through the price signal in the grid tariff, while it could also be organised as regional and local flexibility market places, where the grid operators pay aggregators like ESCOs to provide flexibility in specific locations when needed.

The demand side flexibility reserve is already substantial, and with the rise of e-mobility it is growing. In the building sector, electric space- and water heating, ventilation and cooling are all to some extent flexible loads that can be shifted at least between hours. EV charging, especially at home, is highly flexible and can easily be shifted from daytime to night-time.

Introduction of behavioural incentives, like neighbourhood competitions, could be equally important to actually mobilise the flexible demand resources in the system. In this regard, new, customer-focused players like energy service companies will play a central role.

Enhance the use of the existing grid

New technology and digitalisation not only enable end users to play a much more active role and providing flexibility and load control; they also provide grid companies with new knowledge and tools to utilise existing grid capacity better. New sensors, big data collection and analytical tools based on machine learning (ML) and artificial intelligence (AI) provide a range of new opportunities. Better information and control enables system operators to adjust risk assessments and operational rules for maintaining the desired level of safety and security of supply. Predictive analysis and targeted fault prevention will contribute to reduce down-time and revision periods. Real-time ambient- and grid temperature data enables optimal use of the grid through dynamic line rating (DLR) – where the available capacity actually increases during cold periods, at the same time as the typical Nordic demand is peaking due to heating load.

A part of the capacity challenge is related to short-term situations, like unexpected outages and system faults, or demand peaks of short duration. There are alternatives to building grids to handle such situations. Grid-sized batteries can help stabilise the grid, avoid outages and reduce system costs. Under current EU legislation, however, battery ownership and operation is outside of the regulated network business, and new business models and access to markets for relevant flexibility services must therefore first be put in place.

When designing the framework for new and relatively unknown types of major power system assets, an holistic perspective is required for provision of fit-for-purpose framework rules as functionality, value and usage will most likely span the range from grid capacity constraint alleviation to advanced real time power system control. These are very different values brought to the system and the overall investment case will most likely be dependent on several different revenue streams that need be co-optimised in order to prove a viable investment case.

In summary, with some intelligent choices it will possible to optimise the use of the existing and future grid and make sure that electricity consumers get the best value for money possible while also delivering on decarbonisation.

Kjetil Ingeberg