Incorrect. A level 10 wizard does not have infinite spell points. Tell that to the level 10 Celestial Pact warlock using the basic eldritch blast with the electric element. A typical level 10 wizard only have 480 spell points without equipment according to the DDO wiki.
This is really a tricky question. Has the level 10 wizard learnt any electric based spells? Does the level 10 wizard has enough spell components for the electric based spells like the DOT Eladar's Electric Surge (which is comparable to the Lightning Bolt)?
Assume everything is enough in theory;
480/20 * (500/100) * (4/10) * 1.3 = 62 houses/year then the wizard needs to drink and rest for mana recovery, probably 8+ hours if we are talking D&D time. Not to mention that the wizard can only hold up to 1000 DDO spell components of the same spell level at a time and then he will need to stop casting the spell and run to the store.
EDIT: I may be incorrect myself. It might be more mana efficient to summon air mephits (but not Air Elementals, since that one is too high level), and have the pet powering the grid; and the pet lasts for 10 minutes instead one off; remembering how House Lyrandar power their airships with Air Elementals instead of hiring wizards for the job.