We present results from an installation of fully roll-to-roll printed and coated polymer solar cell modules in a greenhouse environment over the course of roughly 2 years (650 days). We explored two different device architectures based on either fully carbon-based electrodes or silver nanowire (AgNW)-based electrodes and two different barrier materials. We followed the ISOS protocols while studying the devices in three different greenhouse conditions in the Netherlands and compared to reference devices mounted outdoors in Denmark tested according to ISOS-O-1 and ISOS-O-2. We studied each condition and type in multiples to obtain acceptable statistics and found that the AgNW-based devices performed best in terms of stability.