Swissgrid was able to significantly raise the capacity for the import of electricity on the northern border during a test between February and April 2015. This was possible entirely without changes to the existing grid infrastructure thanks to new planning and forecasting systems. This will result in lower prices for cross-border capacities and a greater harmonisation with wholesale electricity prices in neighbouring countries. At the same time, the security of supply in Switzerland will increase. With the «Strategic Grid 2025» initiative, a further expansion of transport capacity between Switzerland and its northern borders is planned.
Switzerland imports electricity from its northern neighbours especially in winter. However, the available net transfer capacity (NTC) is limited. The construction of new lines is expensive and time-consuming, which is why Swissgrid is endeavouring to increase the NTC by operational and organisational means. A corresponding test was carried out successfully between February and April. The necessary new planning and forecasting systems were set up, in order to be technically capable - by the end of 2014 - of participating in the coupled European electricity markets with respect to an electricity agreement with the EU. This will entail electricity and transport capacity always being sold together. However, if used wisely, the systems acquired for the market coupling will also bring about significant efficiency gains for the Swiss economy, even in the existing market model with energy and transport capacity being sold separately. With the new systems, the NTC no longer has to be calculated using static assumptions. Instead, Swissgrid forecasts the expected flow of electricity based on empirical values and current data on temperatures, wind direction, solar radiation and consumption from all over Europe, which allows a much more accurate capacity allocation.
Significant increase in capacity
Overall, during the test phase it was possible to offer around 600 MW or approximately 35% more capacity in the auctions for transfer capacity at the Swiss border with Germany and Austria compared to the previous year. This corresponds to the output of a medium-sized nuclear power plant. This will result in falling prices for cross-border capacities and a trend towards lower wholesale prices in Switzerland thanks to better market access for Swiss retailers and thus more favourable conditions for large users in the winter months. In extreme cases, the auction prices for cross-border capacity could fall by more than 20%. At the same time, the security of supply in Switzerland will increase, because considerably more energy can be imported if required. In a further test phase in winter 2015/2016, Swissgrid will attempt to further optimise the transfer capacity at the border. The «Strategic Grid 2025» report published by Swissgrid in April 2015 also includes four projects that will have a significant impact on the transport capacity between Switzerland and its northern neighbours Germany, Austria and France. This is intended to increase the import capacity by an additional 2,500 MW.
Net transfer capacity (NTC)
The NTC defines the maximum available line capacity between two neighbouring territories. This transport capacity is auctioned off among the Swiss electricity traders. Based on the total transfer capacity (TTR), each grid operator deducts a safety margin, referred to as the transmission reliability margin (TRM). Next the real installed capacities of long-term contracts (LTC) are deducted. The holders of these contracts must in each case declare by the previous day, whether or not and to what extent they intend to use their long-term reserved transfer capacities. The available NTC results from the TTR minus the TRM minus the LTC. Optimisations aside, the primary objective is to ensure, and if possible increase, grid security and security of supply.
Which interconnectors on the northern border are affected?
Capacity has been increased on the borders between Germany and Switzerland as well as between Austria and Switzerland. Consequently, all interconnectors in these areas are affected.
Which trade directions are affected? Import only or export capacity as well?
Capacity has been increased in the import direction (Switzerland imports).
How large will the expected capacity increase be, and which products will it feed in to?
Current growth can be tracked on the platform Transparency, for example. The average increase is 600 MW. However, it is difficult to predict the extent to which this capacity increase can be repeated during the coming winter months. Based on previous years, it should be possible to maintain this baseline. Given that the initial tests were first carried out this winter and that capacities are reassessed each day, any increase has so far only fed in to daily products. We will only be able to start considering other products once the increase proves to be grid-secure in the long term.
Are the tests complete, and if they are:
- When are the next tests scheduled and how long will they take?
The next tests are scheduled for winter 2015/2016 (depending on progress with preparations and above all the weather situation; expected start in November 2015).
- Have current capacities returned to the same level now as before the test?
Current capacities are in the range of the level seen at the end of the first test sequence. However, these are also checked every day for driveability.
What tests are scheduled for winter 2015/2016? What effects will this have on the various borders with Switzerland?
We are essentially planning to continue the previous tests. However, the current systems will be enhanced with new information and we will be seeking more intensive cooperation with neighbouring grid operators.
If the tests complete successfully, from what date can we expect to see a permanent increase in border capacities?
Once the implemented project proves to be successful from both a process security and grid security standpoint, the processes from the test phase will be directly adopted as operational processes. Nevertheless, capacities may fluctuate on a day-to-day basis depending on the grid situation, even following completion of the 2015/2016 tests.
Are similar tests being planned for an NTC increase for other borders?
Not as yet, but the matter will absolutely be considered on successful completion of this project.