A recent report from SolarCity says it is on track to install more than 1 gigawatt of rooftop solar in 2015. The company reported installations of 153 megawatts during the first quarter 2015, beating its own forecast of 145 megawatts. That compares to 176 megawatts in the fourth quarter of 2014. Installations are up 87% from a year ago.

SolarCity quarterly sales chartThe company has set a target of 1,000,000 customers by the middle of 2018. With more than 218,000 customers at the end of the 2015 first quarter, it has achieved more than 20% of that goal. Getting there will require an annual growth rate of 60%. SolarCity has achieved an actual annual average growth rate of 95% since 2012.

With a target of adding 1 megawatt of new solar capacity in 2015, the company is already well on its way to meeting or exceeding that goal. It booked 237 megawatts of new installations in the first quarter. That’s up 74% compared to last year. Meanwhile, first quarter revenue totaled $67.5 million, up 6% compared with the first quarter of 2014. Of significance to investors, the company showed a loss in the first quarter of $21.5 million. That’s a sizable drop from a loss of $147 million in the same period last year.

The cost of installing photovoltaic panels was $2.95 per watt in the first quarter. That is up 3% from prior quarters, due largely to the rigors experienced by crews during an unusually long and harsh winter. Nonetheless, that figure is down 9% from the same period last year. SolarCity has reiterated its advice to investors that it expects to install 920 to 1,000 megawatts of rooftop solar in 2015.  Second-quarter revenue is expected to be between $86 million to $92 million.

SolarCity is the largest rooftop solar company in the United States. It’s chairman, Elon Musk, is also the CEO of Tesla Motors and SpaceX. It has pioneered many of the market innovations, such as no-money down leasing, that have driven the explosive expansion of rooftop solar in America.