Mountain View-based Ausra, a developer of tuility scale, concentrated thermal solar power systems, has been acquired by French firm AREVA, AREVA announced Monday. Financial terms of the buy were not disclosed. Ausra was venture backed by Generation Investment Management, KERN Energy Partners Management, Khosla Ventures, Kleiner Perkins Caufield and Byers, and Starfish Ventures, and raised over $126M in funding.