Absorption chillers perform the thermodynamic alchemy of converting waste heat into coolness. Interestingly, solid oxide fuel cells and absorption chillers may have some of the lowest costs and CO2 for powering and cooling AI data-centers. This 14-page report explores the opportunity, costs and challenges.
Some power generation sources produce both electricity and waste heat. Absorption chillers can convert that waste heat into coolness. Hence could this combination provide both data-center power and data-center cooling, more economically and with lower carbon, than the traditional approach of using electrically-driven HVAC? This question felt interesting to explore in a dedicated research note.
A fascinating avenue to get net zero back on track, more broadly, while also enhancing energy security and competitiveness, would be to capture more waste heat, including by turning heat into coolness, via absorption chillers. Market sizes are quantified on pages 2-3.
How does an absorption chiller work? The four key stages, in the evaporator, absorber, generator and condenser, are described clearly and concisely on pages 4-5.
What does an absorption chiller cost? Capex, opex and total costs of cooling are drawn from our economic model of absorption chillers, in cents per ton-hour and in $/kW-th, and compared with mechanical HVAC equipment on pages 6-8.
Hence how do the costs compare for powering and cooling a data-center using (i) grid power and mechanical HVAC (ii) CCGTs and mechanical HVAC (iii) simple cycle gas turbines and absorption chillers (iv) Solid Oxide Fuel Cells and absorption chillers? The answers on this comparison surprised us, per pages 9-11.
Challenges with fuel cells and absorption chillers should be considered, before getting overly excited, hence some recent successes and issues are summarized on pages 12-13.
Companies producing absorption chillers and solid oxide fuel cells, including our review of Bloom Energy’s patents, are on page 14.