Is there a way (script) to get the daily consumption for a specific time period, in other words if I put the start date as 05-01-2012 and the end date as 15-01-2012, I want an xml of 10 days worth of kWh values

getAllTotals.jsp and getNewProfile.jsp returns XML results with daily figures. It has totals, and it has profile values.
You'll probably have the best results with getting the start and end totals for every day, and subtracting the one from the other in your spreadsheet for getting the consumption?

Go see in http://www.pnpscada.com/webservices.jsp
Both pages are equivalent, except for which options are default. With getNewProfile.jsp, it only returns the totals when certain variables are specified in the URL, and with getAllTotals.jsp, it only returns the profile when certain variables are specified in the URL.