Canadian Solar Inc. says that its Recurrent Energy business unit has signed two 15-year power purchase agreements with Silicon Valley Clean Energy and Monterey Bay Community Power for a 150 megawatt (MW) solar power system with 180 megawatt-hours (MWh) of battery storage.

The deal is one of the largest contracted solar-plus-storage projects in California to date. Silicon Valley and Monterey Bay began work in September 2017 to obtain what they say will be cost-effective, renewable power for their communities. Financial details of the PPAs were not disclosed.

Power will be supplied from Recurrent Energy's Slate photovoltaic-plus-storage project to be built in Kings County, California. The project is scheduled to enter commercial operation in 2021. Silicon Valley will take 55% of the energy and Monterey Bay will take 45%.

The storage component will allow the system to fill the battery when wholesale energy prices are low and then discharge the energy when prices are higher. The project's lithium-ion battery component is a 45 MW nameplate with 180 MWh of energy capacity, allowing for four hours of energy delivery.

Wind Capacity

In July, Silicon Valley and Monterey Bay said they would invest in a new 200 MW wind farm to be built by Pattern Development in New Mexico. Moneterey Bay signed a 15-year PPA for 90 MW and Silicon Valley signed a 15-year PPA for 110 MW of eligible renewable energy from the project. The wind farm is estimated to produce up to 10% of both power aggregator's annual electricity demand.

The storage component will allow the system to fill the battery when wholesale energy prices are low. Source: U.S. Air Force photo by Airman 1st Class Clayton Wear Construction of the Duran Mesa Wind project is expected to begin in late 2019 and the project is expected to reach commercial operation in late 2020. Power from the project will have a connection for delivery into California via the SunZia Southwest Transmission Project, a 520-mile, 500 kV transmission line proposed in New Mexico and Arizona.

In early September, regulators rejected the New Mexico portion of the SunZia line, saying they did not have enough information to approve the project. The rejection was done without prejudice, meaning that SunZia's developers can submit a new application.

Based in the U.S., Recurrent Energy is a wholly owned subsidiary of Canadian Solar and functions as its U.S. project development arm. Recurrent has roughly 5 gigawatts of solar and storage projects in development in the U.S.