Design Low-Cost Industrial Water Heater

I'm looking for an engineer or a designer who can create a very low-cost water heating system for industrial use.

Key Requirements:
- Consideration of various energy sources (solar, electric, gas or a combination)
- Focus on minimizing costs without compromising essential functionalities
- Understanding of industrial water heating needs

Ideal Skills:
- Expertise in thermodynamics and heat transfer
- Experience in designing cost-effective industrial equipment
- Proficiency in evaluating and integrating various energy sources

The goal is to create the most economical solution possible while ensuring the system meets industrial heating demands.