The firm set a $77 price target on the stock, indicating 63% potential upside from the Thursday closing price.
Shares of the San Francisco company at last check were 10.2% higher at $52.
The firm sees a "strong growth story associated with residential solar" and the company's management team as tailwinds. Sunrun should also see long-term federal policy as support.
Sunrun has been an analyst favorite in recent weeks.
RBC Capital last week called the company "the leading player in the rapidly growing U.S. rooftop solar market," while placing an outperform rating and $81 price target.
RBC analyst Elvira Scotto said in a note that Sunrun "has roughly 25% of the total residential rooftop market, and its size, scale and brand provide advantages for acquiring customers and securing better financing."
Scotto said she saw continued growth in rooftop solar as solar-module costs decline and "home battery options and virtual power plant agreements provide additional growth opportunities for RUN."
The company offers both residential rooftop solar and battery storage in every state in which it operates except Wisconsin.
Last month Susquehanna Financial analyst Biju Perincheril initiated coverage of Sunrun with a positive rating and $75 price target.
Goldman Sachs analyst Brian Lee upgraded the company to buy from neutral.
And Morgan Stanley's Stephen Byrd upgraded the company to overweight from equal-weight, while cutting his price target to $86 from $89.