The pressure on the Dutch electricity grid will increase in the coming years. Because our sustainability ambitions mean that we will increasingly use electricity for our transport and for heating our homes, factories and offices. But also because the generation of energy is shifting from a central source to numerous local sources spread throughout the Netherlands. Sources whose output also fluctuates much more than that of traditional power plants. To accommodate this with the current energy grid, there are roughly two options. A costly grid reinforcement or looking for alternatives to reduce consumption and supply peaks. Interflex is an EU innovation project in which grid operator Enexis and project partners TNO and ElaadNL participate. In this project, we test alternatives in practice in order to arrive at sustainable solutions for keeping energy available and affordable. Everywhere and always.

Consumption control through local marketplace

To reduce the daily peaks in energy demand, Interflex is currently testing a concept for a local marketplace where grid operator Enexis can negotiate with providers of services that can control the consumption of energy (such as the provider of an app for low-cost charging of electric cars). Enexis will subsidize them through the marketplace for shifting their customers' energy consumption. For example, if these companies ensure that their customers charge the car at night instead of during the day. In this way, Enexis can substantially reduce the load on the electricity grid at peak times in one fell swoop and the grid does not have to be made heavier.

Test variable capacity for central battery

Interflex is also currently experimenting with a new type of variable capacity connection. We are going to use this connection within Interflex to connect the central battery to the electricity grid. At times when the electricity grid is heavily loaded, the capacity of the central battery is momentarily lower, making the charging and tapping of energy slower. But outside the peak moments, the capacity is actually extra high. So then the battery actually works faster.

USE CASE 1 - SMART ENERGY STORAGE VIA A BATTERY
The purpose of this demonstration is to test technically, economically and contractually whether smart storage is usable in the form of commercial storage. Centralized storage should be valued with the help of all parties involved: the national grid operator, local grid operator, storage operator, prosumers. It demonstrates the applicability of having storage units on a large scale at substations or at street level, to control energy demand in this way. The possible capacity of the central storage unit is between 250 and 500 kWh.

To enable interaction between actors, markets and local resources, the "Local Infrastructure Management System" LIMS was devised. The goal is to enable a local interface to and from potential flexibility sources of energy.

USE CASE 2 -FLEXIBILITY THROUGH ELECTRIC TRANSPORTATION
Enabling optimal activation of all available local flexibility offered by the locally available charging stations for the purpose of congestion management on the energy network. The charge point operator (CPO) manages electric transport charging by applying different mechanical to release the potential of flexibility in electric transport. It can aggregate the flexibility and offer it to e.g. the national or local grid operator through the "flexibility aggregator platform" (FAP). This use case conceptualizes, implements and validates the technical aspects of "long-term flex procurement contracts" to facilitate the flexibility needs of the local grid operator. The rest of the flexibility/capacity can be purchased by program operators (BRP) and the national grid operator. This increased local flexibility allows a large group of consumers to actively offer their flexibility to the energy markets. The local grid operator becomes the market manager by coordinating with "flexibility aggregator platforms" (FAPs), by requesting flexibility offers to various commercial parties, for the next day. This is most likely to be the situation when congestion is involved, but it is also possible that the Program Responsible Parties (BRPs) and/or the national grid operator perform this role.

USE CASE 3 - MARKET MODEL FOR ENERGY DEMAND FLEXIBILITY
This demonstration technically, economically and contractually validates the usability of an integrated flexible energy market based on a combination of static battery storage (Smart Storage unit) and electric transport. One aggregator manages storage and another manages electric charging stations. The two aggregators compete through the flex market, both providing flexiblity to the different stakeholders (such as grid operators). The two types of flexibility (storage and electric) have different characteristics and most likely different user constraints (e.g., drivers of electric cars want their car charged within a certain time). This results in different marginal costs of flexibility and therefore more dynamic earnings and more competition are possible. In this use case, a market mechanism is used to trade flexibility between the two aggregators and the grid operator. Based on financial fees for flexibility. To avoid predicted congestion on the grid, the grid operator purchases the required flexiblity from one of the aggregators based on the cost of the flexibility. This results in the most cost efficient solution for the grid operator.