Essentials gets you access to the vStorage APIs for Data Protection. This means that you could actually look at some of the free backup products available. Veaam has a free solution: http://www.veeam.com/virtual-machine-backup-solution-free.html
These products would allow you to backup up your VMs while powered on and avoid a scripted solution altogether. From there you could use rsync or other to move the flat files to your remote site.