This is an opportunity to work alongside an outstanding, multidisciplinary engineering team in a fast-paced startup environment. You will be part of Rondo’s Core Technology team and contribute directly to the analysis and development of thermal and fluid systems at the heart of our high-temperature heat battery platform — performing real engineering calculations that shape how our systems are designed, optimized, and deployed. 

What You Will Do (key responsibilities for this role include but are not limited to): 

• Support thermal and fluid performance analyses using 1D simulation tools (e.g., AFT, Ebsilon, Aspen, or equivalent) and first-principles hand calculations to characterize system behavior across operating conditions. 

• Assist in sizing and performance evaluation of fluid system components including pumps, blowers, fans, heat exchangers, valves, dampers, and air-flow equipment. 

• Develop and validate steady-state and transient thermal models for energy storage and heat transfer systems, comparing simulation outputs against test data and analytical predictions. 

• Perform pressure drop, flow distribution, and energy balance calculations for ducting networks, piping systems, and process loops. 

• Apply fundamental thermodynamic and fluid mechanics principles to evaluate system efficiency, identify performance bottlenecks, and support design improvements. 

• Assist in developing and maintaining engineering calculation packages, spreadsheets, and simulation scripts used for design verification and performance tracking. 

• Support test planning and data reduction: process raw test data, produce performance plots, and compare results against model predictions. 

• Contribute to equipment specification and vendor data review for pumps, blowers, heat exchangers, and related process equipment. 

• Participate in design reviews and technical discussions; prepare concise technical memos and summaries as needed. 

What You Will Bring: 

• Currently pursuing a Bachelor’s or Master’s degree in Mechanical Engineering, Chemical Engineering, or a related discipline; completion of core coursework in thermodynamics, fluid mechanics, and heat transfer required. Master's degree is preferred. 

• Foundational understanding of energy systems, including thermal cycles, heat exchangers, pumps, blowers, fans, and air-handling equipment. 

• Familiarity with 1D thermal-fluid analysis: ability to set up energy and mass balances, apply Bernoulli and Darcy-Weisbach principles, and interpret pump and fan curves. 

• Exposure to at least one simulation or calculation tool such as AFT, Ebsilon, MATLAB, Aspen Plus/HYSYS, or equivalent; willingness to learn new tools quickly. 

• Comfort working with engineering equations and unit conversions across SI and imperial systems. 

• Strong academic record with a genuine interest in clean energy, climate technology, and sustainability. 

• Attention to detail and commitment to producing accurate, well-documented engineering calculations. 

• Organized self-starter with excellent time management skills and the ability to take ownership of assigned work. 

• Effective communicator with strong writing skills and the ability to present technical results clearly to peers and senior engineers. 

Bonus Points! 

• Hands-on coursework or project experience with heat exchanger design, pump/fan system analysis, or duct/air system sizing. 

• Familiarity with CFD/FEA tools for flow visualization or validation. 

• Exposure to energy storage, renewable energy, industrial thermal systems, or power plant operations. 

• Prior internship or co-op experience in a mechanical, process, or energy engineering environment. 

What We Offer:

• Catered lunches on-site
• Rondo HQ is close to Oakland airport - one block from the Bay - and has stunning Bay views!

This role necessitates either being on-site at our Alameda HQ 2-3x per week OR remote in Central Florida. The estimated annual hourly range for this role is $35 to $45. Please note that some pay bands may have wide ranges of compensation to accommodate candidates' diverse sets of skill levels and experience. 

About the Company  

We are transforming industrial decarbonization with our innovative Rondo Heat Battery technology. Rondo is deploying low-cost, zero-carbon Rondo Heat Batteries to accelerate the deployment of renewable energy and to significantly decarbonize industrial processes that are commonly thought of as "difficult-to-decarbonize". Our heat batteries charge from intermittent renewables to provide high temperature, continuous heat for customers safely, reliably, at an unprecedented 98% efficiency - and at a cost point that is lower than any other method.  

Our technology is designed to replace fossil-fired boilers. By enabling industries to adopt renewable energy without costly factory changes, we are accelerating the transition to a sustainable future. With over $160 million in funding and partnerships across critical industrial sectors, Rondo is scaling rapidly to meet global demand.

Rondo Energy is an equal opportunity employer. We strive to create a supportive and inclusive workplace where contributions are valued and celebrated, and our employees thrive by being themselves and are inspired to do their best work. We seek applicants of all backgrounds and identities, across race, color, ethnicity, national origin or ancestry, citizenship, religion, sex, sexual orientation, gender identity or expression, veteran status, marital status, pregnancy or parental status, or disability. Applicants will not be discriminated against based on these or other protected categories or social identities.

Rondo is committed to the full inclusion of all applicants. If reasonable accommodation is needed to participate in the interview process, please let our recruiting team know.

We proactively work to design hiring processes that promote equity and inclusion while mitigating bias.

Note to Recruitment Agencies: Rondo does not accept unsolicited agency resumes. Furthermore, Rondo Energy does not pay placement fees for candidates submitted by any agency other than its approved partners.