Ernst Sack

Founding Partner,
Blue Bear Capital LLC

Ernst is a Partner at Blue Bear Capital, a venture and early growth equity fund focused on digital technologies for the energy industry. Blue Bear investments apply technologies like IoT, machine learning, and cyber security across oil and gas, solar, wind, and energy infrastructure.

Ernst has participated on the Boards of Directors of over ten conventional and renewable energy companies. Before Blue Bear, he spent nine years at Riverstone, the world’s leading energy specialist private equity firm with $34 billion in assets under management and over 120 investments. He is also a Venture Partner at Cimbria Capital, a private equity and growth capital firm focused on the water and agriculture industries. Since 2012 Ernst has been an active independent investor in technology-enabled businesses disrupting traditional industries. Previously, he worked in the Mergers & Acquisitions team at Citigroup covering the oil and gas, renewable energy, and transportation sectors.

Ernst graduated with honors from Georgetown University with a degree in Science, Technology & International Affairs and a certificate in Eurasian, Russian & East European Studies. He received his M.B.A. from Columbia Business School and London Business School through a joint degree program.

United Kingdom

T: +44 20 7384 8056
Bedford House
69-71 Fulham High Street


T: +65 6590 3978
78 Shenton Way

Houston - USA

T: +1 713 353 4633
Two Allen Center, 1200 Smith Street, Floor 16, Suite 6061

Houston, TX, 77002


Lagos - Nigeria

T: +44 787 550 6366
No. 92 Oduduwa Crescent,
G.R.A., Ikeja
Lagos State

South Africa

+27 21 001 3884
Great Westerford
Corner Main Rd & Dean Street
Newlands 7700
Cape Town