Case study 1

Demonstration at residential building scale Oud-Heverlee, Belgium Duration of demonstration July 2015 - November 2016

The last dozen of houses in a residential street in Oud-Heverlee, Belgium, are equipped with a range of technologies to provide a maximum of load shifting potential: fuel cells, batteries, small scale thermal storage, seasonal thermal storage and improved monitoring and control. Interoperability is given considerable attention, in order to pave the way for cooperation between different technology providers and move to plug and play solutions.

This demonstration contributes to unfold the value of storage for the end user, the distribution grid operator, the energy provider and a potential third party aggregating the flexibility.

This demonstration will tell you the STORY of how storage can change the way to fulfill your domestic energy needs.

Demonstration at residential building scale

This demonstration contributes to unfold the value of storage for the end user, the distribution grid operator, the energy provider and a potential third party aggregating the flexibility.

This demonstration will tell you the STORY of how storage can change the way to fulfill your domestic energy needs.

Oud-Heverlee, Belgium

The residential buildings are located in a single street in Oud-Heverlee, Belgium. They are located at the end of the feeder, facing the typical challenges of power quality in terms of interrupted supply and voltage profile. The zone consists of a mix of old and new houses, has 20 kW photovoltaic energy generation, hybrid PV and vacuum solar thermal energy, air to water and geothermal heat pumps as well as e-cars.

Today, installing new technologies and integrating them into a system, requires considerable time by skilled workforce. In order to make storage technologies more accessible, STORY puts a large effort in interoperability. The hardware installation in the residential buildings is orchestrated by experts in hardware communication. In STORY, these experts will, together with the technology providers, continue to work on the topic to improve easiness of installation and thus positively impact installation and commissioning in the long term.

Storage is integrated such that different business models can be tested and evaluated: what is the impact for all stakeholders if the storage is operated focusing on reducing the energy bill of the end user, what if it answers a demand of the grid operator or the energy provider?

The residential demonstration brings a variety of technologies and combinations. Some of the buildings will be equipped with a fuel cell, some will get a battery, others get a combination of fuel cell and battery. They will all be equipped with advanced monitoring and control systems. One building, the smart building, currently already equipped with all available smart technologies from smart household appliances over an e-car to advanced control for ventilation, takes load shifting a step further by introducing a seasonal thermal storage of 25 000 liter, combining PVT with natural cooling to load the shallow geothermal system and extending the battery storage to provide grid independency for a couple of days.

At the end of the demonstration, this demonstration should have showed what local storage can mean for all stakeholders involved, including society as a whole.

Responsible partner: THINK E

 

 

“This is a marvelous demonstration to lead, where engaging home owners, coordinating technology providers and being creative are all coming together. No desktop project, but being out there and getting it done!”
Leen Peeters, Think E

15 Jul 2015
Start of site preparation in smart building
15 Aug 2015
Installation of cooling basin 1 and seasonal storage tanks in smart building, site check in other buildings for fuel cells and batteries
15 Oct 2015
Installation of underground seasonal storage tanks in smart building, installation of measurement equipment in all residential buildings
1 Dec 2015
Part 1 of installing cooling reservoir 2: digging for the first reservoir and install the connection with the waterfall. As reservoir 2 needs to provide a large surface area for evaporation and cooling through convection, while being integrated with limited impact on the natural shape of the terrain, it consists of 3 connected reservoirs. A waterfall connects them with the technical rooms and ensures a high level of oxygen in the water.
18 Mar 2016
Working on a test-case hybrid PV panel
11 May 2016
The Viessmann vacuum boilers are installed on the roof of the technical room. It is a precision work, as the roof was just the right size with no spacing left. The solar boilers will heat up the underground storage tanks during summer for use in winter.
Installation of state of charge measurements on the seasonal storage tanks
1 Jun 2016
Installation of fuel cells in the other buildings. Finalisation of installation of hydraulic components, measurement equipment and batteries. Installation of fuel cells in the other buildings.
11 May 2018
An optimization tool is never done ... but close to it: optimizing both battery energy and battery inverter power as well as number of PV panels. Pricing is time dependent and injection fee is based on real values. Next is adding smart car charging!
12 May 2018
100% self-sufficient (hence off-grid) since 10 days again. This includes all residential use, the pumps in the thermal lab and the 2 electric vehicles.

Seasonal thermal storage

Two steel tanks are used as seasonal thermal storage to hold a total of 25 000 liter of water with a maximum temperature of 90 ⁰C. The tanks are installed underground, covered with thick layers of Foamglas insulation first and XPS on the outside, all inside an EPDM sealed bag to ensure the insulation remains dry and effective. Steel tanks were preferred above concrete tanks due to the 3D-thermal pressure caused by the stratification in the tank: a temperature difference of 60 ⁰C can occur on a height of 1 meter. Steel tanks do require cathodic protection on the inside, to prevent corrosion, but are solid and can resist high pressure.

The tanks will be loaded with the vacuum solar system that will be installed spring 2016.

The wiring for the temperature sensors will be connected to the KNX system

The wiring for the temperature sensors will be connected to the KNX system that combines all signals from active components on de demonstration site. In order to be safe in a rather aggressive environment of screed (used to fill the narrow zone between Monobloc and ground), the sensor wiring is protected in plastic tubing.

Cooling basin

The hybrid PV produced water of around 30⁰C to 35⁰C, too high for charging the shallow geothermal system. Therefore, a cooling basin was proposed and in agreement with local regulators it was decided to experiment with both a deep large basin and undeep basin with higher flow rate. The deep basin will be used as buffer for medium to low temperature heat in spring and fall, to feed the geothermal heat pump or melt the snow on the hybrid PV panels.

The deep basin has to be able to resist temperatures of up to 40⁰C, excluding a wide range of on site constuctions with liners and monoblocs with polyester. The remaining options are epoxy and inox, of which the latter is too expensive for the purpose. Therefore, a standard monobloc is installed, insulated and fully equipped with temperature sensors.