Caithness and ArcLight announce geothermal, wind and solar power agreement

2 August 2007 — Caithness Energy LLC and ArcLight Capital Partners LLC said that they have reached an agreement whereby an affiliate of ArcLight will acquire interests in 18 geothermal, wind and solar renewable power generation projects (the “Projects”) with an installed capacity of 824 MW from Caithness through a series of transactions.

In connection with ArcLight’s acquisition, it will assume the responsibilities for the operation, maintenance and management for ten of the Projects.

The acquisition is subject to certain closing conditions including Hart Scott Rodino approval and other regulatory approvals and consents. The transaction is anticipated to close in the third quarter of 2007. Citigroup Inc. acted as financial advisor to ArcLight.