Ambitious is a general descriptor that can be applied to power as well as other advantages that lead to success:
adjective
1 Having or showing a strong desire and determination to succeed:
a ruthlessly ambitious woman
ODO
Since power is a key to success in most endeavors, people with a strong desire to succeed are often perceived as power-hungry, even if the pursuit of power is not their ultimate goal. Other people define success in terms of accumulating power, and these ambitious people are truly hungry for power. When describing projects, ambitious is more likely to have a positive connotation, but when applied to people, it can often harbor the negative connotations of the insatiable desire for power and wealth, as seen in The Huguenots, by Samuel Smiles:
He [Louis XIV] was proud, ambitious, fond of power, and believed himself to be the greatest of men.