CSEM has developed a lean control architecture for microgrids, with an implementation in direct current (DC) microgrids. The novelty of this architecture support both local and system-level objectives with a unique storage system. The benefit of this patented solution can now be freely evaluated online.

Simulation tool

With our online simulation tool, you can evaluate the benefit of DCSMART over a system without batteries and basic energy buffer batteries. This tool allows you to freely set your system specifications (i.e. PV production and load consumption profiles, batteries, and electricity tariffs) and compare the economic benefits of each solution over a yearly simulation.

Democratization of prosumers and challenges

With the cost of photovoltaic power generation getting more and more attractive, private houses and industrial buildings have a clear financial interest in producing and consuming their own energy i.e., to become “prosumers”. By increasing their self-consumption, prosumers can reduce the amount of energy purchased from the distribution grid and thus save on their energy bill.

On the other hand, the fact that the grid infrastructure costs are mainly driven by peak power, rather than energy, is leading to an increasing fraction of retail electricity prices being based on peak power consumption. This evolution presents a challenge for prosumers with highly variable power profiles.

Microgrids as promising solution

To tackle these challenges, microgrids with storage systems on the prosumer side are a promising way to manage the complexity of power networks with an increasing number of distributed, variable renewable energy sources.

Through the DCSMART project, CSEM has developed a control architecture for microgrids to benefit both prosumers and distribution system operators (DSOs). The design has been experimentally validated in an industrial environment.

DC architecture for improved efficiency

A high share of components in prosumer systems natively operate in direct current (DC) (e.g., photovoltaic (PV) fields, batteries, and an increasing number of loads) so using a DC power distribution system provides substantial benefits over alternating current (AC). Indeed, it allows the use of fewer and more efficient conversion stages, thus increasing the overall efficiency of the system.

In the proposed system architecture, a DC bus is interconnecting an AC distribution grid, batteries, PV fields and loads with the use of suitable AC/DC and DC/DC converters.

Multi-service control strategy

The control strategy is the real added value of the developed solution. Its purpose is to control the charging/discharging of the batteries to provide both local and system-level services. More precisely, it allows to provide the following services:

  • Increase of self-consumption — local consumption of locally produced energy — to reduce energy charges for prosumers.
  • Perform peak-shaving on the distribution grid — limiting the peak power exchanged with the grid — to reduce capacity charges for the prosumers and peak load for DSOs.
  • Perform ramp-rate control of the grid power — limiting the rate of variation of power exchanged with the grid — to ease the grid stability management for DSOs.

To provide these services, the storage capacity of the battery is virtually split in sub-capacities which are allocated to each service. This approach allows to easily adapt the capacity distribution among the services and thus adapt optimally to any load profiles or electricity tariffs. This patented strategy is flexible and easily scalable to any application. It can also operate in more conventional AC environments.

Economic benefits

Thanks to its ability to perform multiple services, the economic benefits of this solution are significantly higher than with a basic energy buffer strategy (where excess production is stored in the battery until it is full, and a lack of production is compensated by extracting from the battery until it is empty).

In a domestic application, the developed strategy reduces operating costs by 6% to 48% (depending on electricity rates) compared to a standard strategy with an equivalent storage capacity. For an industrial application, this reduction varies from 1.5% to 13%. This allows a return on investment for batteries up to 4x faster.

Key points

  • Multiple services: Self-consumption, peak shaving, ramp-rate control
  • Proven economic benefits: up to 4x faster return on investment for batteries
  • Scalable & adaptable: For residential, commercial & industrial buildings
  • Patented: Innovative control architecture

The DCSMART project has received funding in the framework of the joint programming initiative ERA-Net Smart Grids Plus, with support from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 646039.

CSEM received funding for this project from the Swiss federal office of energy and from Viteos, Neuchâtel’s multi-energy utility, under contract SI/501375-01.