A set of 15 thermomechanical design rules is derrived to support and accelerate PV module developments. Three methods are developed and applied: 1. Thermomechanical FEM-simulations of PV module designs. 2. µ-Raman spectroscopy of laminated solar cells. 3. Solar cell integrated stress sensors (SenSoCell®). The concept of specific thermal expansion stiffness E ̂_α is introduced as a measure of how much thermal strain one material induces in another.