Using building integrated photovoltaics BIPV can contribute to lowering the need for purchased electric energy and increasing security of supply for the project. It can also make the good environmental profile of the project more visually present.

Section east — west

Installing PV on the roof is one of the most obvious solutions in the building, as the large, unfragmented surface receives abundant sunlight. An area of more than 2000 m2 is well suited for PV installation, and flat roof elements is preferred to maintain the clear outline of the building. Elevating the northern roof corner of the closed volume to the west, would make the entrance situation more expressive and dramatic and the roof surface very feasible for PV. Using excess heat from the PV for domestic hot water will increase the efficiency of the system.

The skylight area is about 350 m2, but is unfortunately tilted to the north, which make it unsuited for PV integration. Tilting it to the south would not deteriorate light conditions noticeably, as the light reaches it destination as secondary light anyway. This location is a good place to express the environmental profile of the building through crystalline PV arrays with well dimensioned and generous spacing between the cells. This will give interesting light qualities in the central atrium, which is dominating the interior. Installation in large sections on the windows is not feasible with the shade conditions on the fagade.

Only a ribbon on the lower part of the windows is suitable in terms of output, but a fixed installation here would affect the view from the work stations in a negative way.

The walls have large proportions of window area and are curved. Overhanging canopies and galleries make them poor areas for installing PV. Some narrow belts can be added at the edge of the external galleries to the south, but as this can look aesthetically detached from the fagade, it is not recommended. The canopy and external galleries to the south create complicated shading conditions. This makes wall integration of PV somewhat difficult.

Using PV as solar shading is a logical response to regulating the solar conditions to the south. Presently, local shading is handled with interior blinds. This solution is cheap, but can contribute to high interior temperatures. Using exterior elements to increase the efficiency of the PV elements and at the same time reducing internal heat load is the most feasible approach. The large window surfaces and overhangs create complex conditions. The elements need to be placed on the exterior of the galleries to avoid shade. The distance between the wall and the elements is favourable in terms of ventilating the elements. Mobile elements can be connected to the web system of workplace control. Sun tracking PV elements can give good electricity outcomes of the system and give the fagade a dynamic expression.

The slightly tilted canopy that runs along most of the edge of the roof is well suited for installing PV in a section. It is important to use canopy elements that have both a PV and a regular version with the same expression.

The building is placed on the south west corner of the site, bordering to a green bridge structure that covers the highway. The triangular site has an area to the north and to the east, towards the river. The northern end of the site lies somewhat undefined behind the car access. Free standing sculptural PV elements can be installed on this part to create an interesting and more elaborated entrance situation. PV can be fitted over some of the guest parking, but this would make the entrance situation quite crowded. It is therefore not recommended.

The east side of the site has an open area over the subterranean cafeteria. Using transparent PV elements could supply this important facility with abundant natural light and give it less of a dungeon feel. Several smaller light shafts can make the underlying space evenly lit and less dominated by the installation, and would fit better in the terrain than one large shape.

Sketches illustrating some concepts for PV application and facade consequences, including integration on two roof surfaces, the skylight, in light shafts, in the terrain and as long lamellas on the south fagade for shade.

Sketches illustrating some concepts for PV application and facade consequences, including integration on two roof surfaces, the skylight, in light shafts, in the terrain and as a large sliding sheet on the south facade.

The project is finished with most of the initial investigations of the building and the site, and will continue with elaborating different concepts for PV integration. Common approaches of applying PV on roof surfaces give the least implications for the aesthetical image, but traditional methods for applying PV on the facades have proved difficult concerning both solar access and aesthetics. The project continues to investigate further possibilities for PV solutions for facades and for installation on the site that can contribute to a dynamical expression and adding features to the building that can improve the working environment.

References:

"Tomorrows office”, Santa Raymond, Roger Cunliffe "The creative office”, Jeremy Myerson, Philip Ross The article “Drontene”, Sissel Morseth Gromholt

The report “Passsive climate measures for Pynten”, Tor H Dokka, Marit Tyholt