The National Science Teachers Association has some great science PD resources and one of my new favorites are free 2 hour online courses called Science Objects. These modules of PD are free to members and non-members alike and are actually parts of larger science PD modules called SciPacks. SciPacks are 10 hour courses and are $32-$40 depending on membership status.
If you want to try a 10 hour SciPack- The Solar System is currently FREE regardless of membership status.
Applications for Science Teachers: If you have moved a grade level or content area- this could be a great science content refresher. Elementary science teachers may find this to be a great source of science content PD that can be completed on your own time.