An ancient lake and a new lake
A big lake 380 years ago land reclamation changed Heerhugowaard into a large agricultural polder with urban development. The City of the Sun is the biggest partner in the European Sun Cities project that aims at making a significant contribution to the European targets for CO2 reduction and implementation of PV systems.
The project is built near a lake that is used also for recreation. There is a water system with ecological water purification that is independent of the water system in the polder in which the project is located. Water recreation calls for high water quality, which is obtained by excluding the nutrient-rich polder water and creating a polder within a polder. A polder is an area below sea level surrounded by dikes with a controlled water level. The closed water system of the City of the Sun has its own (controlled) water level and is filled with rain water only from the roofs of the houses and the surfacing in the project.
The average water level is some 60 cm above that of the surrounding polder area. As a result the seepage water from that area cannot penetrate the area ís separate water system and the water level does not fluctuate more than usual, 70 cm approx. This makes it necessary to leave out the usual crawl spaces under the houses. For the inundation of the lake the cultivation soil, the nutrient-rich top layer, has been removed and reused in the creation of a hilly forest area near the City of the Sun. The entire layout of the project is based on a closed soil balance system, saving energy because less soil had to be transported.
City of the Sun, facts and figures
1600 energy-saving houses built according to ISO++ standard; 100 hectares of residential area, 100 hectares water and 100 hectares forest; 25,000 solar panels (50,000 sq.m.) producing 3.75 MW photovoltaic energy;
Emission: 6,592 tonnes of CO2 for the entire location (emissions of built-over area, facilities in the area and mobility), compensated in full by solar panels, three wind turbines and the forest); 2,500 tonnes a year reduction of CO2 emission by emission-restricting measures (for entire HAL Vinex location); Artistic glass roof on Atlanta primary school, glass panels attached to solar panels by means of a unique click system.