Miela Mayer is Investor and Operating Partner at Third Sphere. Her firm bio says she joined in 2022 and focuses on hardware investing and non-dilutive capital sources for climate tech, and that she is based in San Francisco. Before Third Sphere she spent over two years at Bain & Company consulting for utilities and sustainability clients, and worked in climate finance at the New York Green Bank and Bloomberg New Energy Finance. She holds a dual BS from Yale in Environmental Engineering and Environmental Studies plus a scholar certificate from the Yale Climate and Energy Studies Institute. She is the named author or co-author of Third Sphere's published investment write-ups for Sention, SwellCycle, AccessGrid, Focal and Return To Vendor.
Education
Dual BS in Environmental Engineering and Environmental Studies, Yale University
Previous Experience
Climate finance work, per her Third Sphere bio, Bloomberg New Energy Finance
Climate finance work, per her Third Sphere bio, New York Green Bank
Consultant, over two years, covering utilities and sustainability, Bain & Company
Notable Investments
SentionSwellCycleAccessGridFocalReturn to Vendor
Career Timeline
2022
Joins Third Sphere, per her firm bio, focusing on hardware investing and non-dilutive capital sources for climate tech.
2025
Authors Third Sphere's 27 March 2025 'Why We Invested in Sention' post.
2025
Authors the 'Why We Invested in SwellCycle' post dated 6 March 2025.
2025
Co-authors Third Sphere's 28 October 2025 'Why We Invested in AccessGrid' post.
2025
Co-authors Third Sphere's 18 November 2025 'Why We Invested in Focal' post.
2026
Authors Third Sphere's 30 March 2026 'Why We Invested in Return To Vendor' post.