Vaisala 3TIER Services Supports First Pattern Development Solar PV Project

Pattern Development's 122 MW marquee solar project, Conejo, receives financing and begins construction in Chile, leveraging due diligence work supported by Vaisala

Vaisala, a global leader in environmental and industrial measurement, has announced its role in supplying a comprehensive range of due diligence services to Pattern Energy Group LP ("Pattern Development") for its 122MW Conejo Solar PV project in Chile. The work played an instrumental role both in informing financing terms and setting ongoing production expectations at the site, which has recently commenced construction.

While primarily known for its experience in developing wind projects, Pattern Development is bringing its expertise to the solar sector. Once constructed, the Conejo project will not only be Pattern Development's first operational solar site, but also one of the largest solar PV projects in the rapidly expanding Latin American market.

Due to the size and nature of the site, reliable early-stage data and sophisticated long-term generation estimates played a critical role in securing capital and advancing the $205 million project towards the construction phase. As the company expands into solar development, Pattern Development chose Vaisala 3TIER Services as a trusted partner, building on a long history with the company's wind energy consulting practice.

"Latin America is a strategically important market for Pattern Development," explains Chad Ringley, Director of Energy Analytics at Pattern Development. "When entering a new region or working with a new technology, we require partners with local experience, strong technical expertise, and quality customer service. Vaisala has delivered all three in the past, so it was an easy and comfortable choice for the Conejo project."

In evaluating long-term production uncertainty, Vaisala provides a sequence of services leveraging available ground data in conjunction with long-term hourly satellite-derived data. This long-term data, from Vaisala's extensively validated global solar dataset, addresses nearly two decades of climatological variability through hourly solar irradiance and weather information for any location on the planet.

For Conejo, Vaisala translated this atmospheric and irradiance data into multiple long-term energy generation estimate scenarios using a comprehensive approach to time-varying production for project-specific technologies. This approach combines long-term environmental context with a full propagation of uncertainty and associated losses and derates. To help Pattern Development determine optimal plant configuration, Vaisala also delivered detailed probability analysis on a custom basis for multiple project sizing and technology scenarios.

Chad Ringley added, "We were pleased with Vaisala and its flexibility in ensuring that all of our questions related to the radiation assessment were addressed."

Vaisala is an expert in solar and wind measurement, assessment, and energy forecasting. To learn more about this work or how Vaisala can support your company, visit Booth #634 at the Solar Power International conference in Anaheim, September 14th - 17st. For further conference details, please visit our event home page at

For more information on the range of services offered by Vaisala to the renewable energy sector, please visit

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