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Best practice case study: Shipshape

A floating house being towed into position.

The Schoonschip community being set up – in the virtually self-sufficient neighborhood with floating houses, a new form of energy management is emerging from the water. (Copyright: Fraunhofer ITWM)

Shipshape

Energy management system developed by the Fraunhofer Institute controls floating settlement in the north of Amsterdam

In the Netherlands, a floating neighborhood is being built around a sustainable and virtually self-sufficient living concept powered by PV installations, heat pumps, battery storage systems and a microgrid which connects all 30 houses. An energy management system links up the individual sectors and ensures that power is always flowing.

It may once have been just a developer’s pipe dream, but it has now become reality at a new site in the north of Amsterdam. In May, 15 pre-built houses were docked on a canal branching off of the IJ river, having been towed there by tugboats and anchored to a series of piers. The new neighborhood on the water currently comprises 22 floating houses, with a total of 30 planned, which will offer space for 46 residential units as well as common areas.

Better together – collaborative efforts beyond the grid connection

What really sets the new neighborhood of Schoonschip apart from the rest isn’t its floating prefabricated houses, but the fact that it is set to be Europe’s largest floating energy self-sufficient neighborhood. Literally translating to “clean ship,” the neighborhood’s name alludes to everything being shipshape. The Dutch word schoon means clean or neat, or even emission-free – all of which describe the new neighborhood perfectly. It does have an electrical power connection, but none for gas. Most of the required energy will be provided by PV modules on the houses’ roofs. Greywater – water that has been used for bathing and laundry, for instance – is to be collected separately and reused. Blackwater from toilets will be used to create biogas via fermentation. The heat from shower water will also be recovered. Green roofs and floating gardens have been designed to bring a little nature into the neighborhood. The future residents see themselves as a cooperative, working together to plan, develop and maintain their living space.

This especially applies to the energy supply. Each house comes equipped with a heat pump that makes use of the heat from the canal. The required electricity will be generated by 500 solar modules and stored in heat pumps and batteries to keep things up and running when the sun isn’t shining. The energy cooperative operates its own microgrid, meaning that all the houses are interconnected. There is only a single shared grid node connecting them to the public grid, used to guarantee the power supply at peak use times or when the batteries are empty or there is little sunlight. For budgetary reasons, the planners decided against a medium-voltage connection, instead opting for the largest possible low-voltage connection at 135 kVA. This is relatively small for the number of residential units, which could lead to congestion and overloading at the grid connection point.

Energy management system keeps everything afloat

Amperix, the energy management system developed by the Competence Center for High Performance Computing at the Fraunhofer Institute for Industrial Mathematics ITWM, will prevent any such issues from arising. The system consists of control units and the myPowerGrid web platform, an interface where energy flows can be transparently depicted using graphics and data analyses. Every house is fitted with an Amperix control box, which uses readable meters to record electricity demand and production, the batteries’ state of charge and the buffer storage tank’s internal temperature. A central Amperix system monitors the three-phase grid connection point and uses the control units in each of the houses to adjust various settings, for instance if batteries need to be charged or discharged, or if the heat pumps need to start storing excess electricity as heat. But the system doesn’t just process current readings – it also produces load forecasts for household consumption and for the heat pumps. It uses the PVCAST smart forecasting system via the myPowerGrid platform to predict solar electricity yields in advance. This will enable the cooperative to maximize its use of self-generated electricity. The connection point’s maximum capacity is the key factor in controlling the system.

Watering down costs with peak shaving

But the goal is not just a local and secure self-supply – there are financial aspects to consider, too. The annual fee for the shared grid connection is determined by factors such as peak power, not just the total volume of electricity drawn from the grid. Amperix reduces the peak power to bring down costs for the community by making optimal use of storage opportunities.

Thanks to special exemptions from many of the usual regulations in the Netherlands, the project has given ITWM the freedom to try out a number of things that would not have been so easy otherwise. “Schoonschip offers us a one-of-a-kind opportunity to refine our neighborhood management technology and put it to work in real-life conditions,” says Matthias Klein, who is responsible for the Green by IT group at the Competence Center for High Performance Computing.

Schoonschip will also offer electric vehicles for the cooperative to share. The wall boxes for the vehicles will be located on dry land on a plot belonging to the residents. The charging stations could be integrated into the Amperix system, too, but the cabling connecting them would have to run over public land, so the wall boxes are not incorporated into the energy management system. It would also be possible to establish a local energy market amongst the residents, but they see photovoltaic solar electricity as a public commodity, so there are no plans to open trade.

Schoonschip is a part of the GridFriends project, funded by ERA-Net Smart Grids Plus and Germany’s Federal Ministry for Economic Affairs and Energy. Centrum Wiskunde & Informatica (CWI, Amsterdam), Spectral (Amsterdam) and evohaus (Karlsruhe, Germany) are project partners. The overarching goal is to optimize the coordination mechanisms between individual energy consumers and producers. (SP)


For more information, please visit the website of Fraunhofer ITWM