Capt_Rich Yes, although due to the threshold you set to 16p, you may well end up with more than 17 slots.
If you had not adjusted the price cap, WW would simply have selected the 17 cheapest slots within the window you have specified (provided you hadn't manually selected a slot yet - which could basically result in WW overwriting your selection).
Now WW will select the cheapest 17 slots within your window, but will additionally also select other slots (beyond the 17) that have a price lower than 16p.
Sounds complicated but hope it makes sense. The requirement is really there for users to take advantage of plunge pricing especially negative prices. No one would want to accidentally miss out on getting some money to use leccy!
