Look for the “Manage Custom Assumptions Tasks” Wizard under the Manage Assumptions node, there you can set the “Cost per kWh” and “Carbon Emissions Per kWh” using your own values. I’m not sure if we currently have a way of changing the “$” symbol… I know at one point it was a talked-about feature request.
At the top right corner of the Manage Custom Assumptions Tasks wizard, there is a “gears” button. Clicking on it will allow you to change the currency and weight (for CO2) units in reporting, as well as generate a Fixlet message to update client dashboards with the new units.
Note that changing the unit does not convert the costs nor changes the calculations, but merely changes the reporting symbols as currency values continually fluctuate.