Housing+ (BOLIG+ in Danish), an apartment building just outside Copenhagen, is Denmark's first net-zero energy building. The owner is Realdania By & Byg and within the building a VisBlue Battery Solution has been installed. In addition to being energy neutral, the building also produces electricity for the residents' use of electrical appliances such as mobile chargers, vacuum cleaner and lighting. The building consists of 10 apartments amassing approximately 1,200 square metres distributed across 4 storeys.
The project came about because Realdania wanted to tackle the challenge of building energy efficient housing.
With Housing+, Realdania has managed to hit the actual zero in terms of energy, in particular due to its partners, VisBlue being one of them.
Energy neutral means that the output from the building coming from the solar panels correlates with the electrical consumption of the residents.
The actual zero has only been reachable due to VisBlue's vanadium redox flow battery. With the flow battery the output for the residents is doubled from 25% to 50%, which means a great deal on the bottom line. Due to this doubling in output the residents will save around DKK 10,000 each year.
The sun doesn't shine around-the-clock and therefore the output will differ throughout the day. Consequently, in order for the residents to have electrical power night and day the energy that is produced during the day has to be stored.
In a vanadium redox flow battery, the electrical power is stored in fluids in stead of solids. This means that the battery can be tailored and changed according to the needs of the housing.
Furthermore, the battery has a life span of 28 years outliving the solar panels installed at Housing+. In addition to the economic benefits, the battery is also fire-resistant as well as environmentally friendly because most of the materials used for the battery can be reused when the 28 years have passed.