Apple Maiden iCloud Data Center  |  Case Study

Hybrid c-Si Solar PV + Biogas Fuel Cell (SOFC) Generation:  24.8 MW

  1. Upon completion in late 2012, the hybrid renewable energy installation at the Apple Maiden iCloud Data Center in North Carolina will be the world’s largest non-utility fuel cell installation, the largest SOFC (solid oxide fuel cell) installation, and the largest private, end-user owned onsite solar array in the United States.

  1. Apple Computer’s renewable energy effort at the (under construction) Maiden iCloud Data Center in North Carolina includes a 20 MW, 100-acre silicon solar PV array, an ambitious 4.8 Bloom Energy fuel cell installation, and plans for an additional 20 MW solar array at a nearby location.  

  2. Apple has indicated that the two solar arrays, coupled with the biogas powered fuel cell installation, will produce 60% of the electrical power required to operate the facility.  The data center has been designed to be extraordinarily energy efficient, a necessity for cooling-intensive, heavy energy consumption data centers.  The facility is in line to receive USGB LEED Platinum certification, something both unique and difficult to achieve in data center development.  Among the energy efficient features are:  A chilled-water system that transfers 10,400 kWh of consumption from peak to off-peak hours; use of outside air cooling during night and cool weather hours; extreme precision in management of cooling distribution; and a construction process that includes 14% recycled materials, diversion of 93% of waste from landfills, and sourcing of 41% of all purchased construction materials from within 500 miles of the Maiden site.

  3. Hybrid Renewable Energy Systems

  4. For more information on hybrid renewable energy systems, see:  Categorizing Hybrid Renewable Energy Systems.    

  5. Project Development

  6. This is not the first instance where project developer and owner Apple Computers has made a strong commitment to renewable energy.  For nearly 10 years, Apple has purchased 100% renewable energy for their operations center in Austin, Texas. Since then, they’ve added the Sacramento, Cork, Ireland, and Munich, Germany operations centers to their list of sites with 100% renewable energy. In 2012 Apple began purchasing direct-access renewable energy for their Northern California facilities including corporate headquarters in Cupertino (which currently uses more than 50% renewable energy, some of which is supplied by Bloom energy fuel cells).

  7. The solar array is powered by SunPower Corporation high-efficiency monocrystalline silicon photovoltaic  solar panels based on a silicon all-back-contact solar cell invented at Stanford University.  SunPower solar PV panels are the world’s first to consistently achieve 20% efficiency and the company currently holds the world record for solar PV efficiency at 22.4%.  When combined with SunPower’s T20 single-axis tracking, the high efficiency E20 PV panels can produce 30% more power than a fixed array.  Since 2002, SunPower has designed and delivered 120 solar power plants worldwide.  Completed projects include 35 MW  of capacity for Florida Power and LIght while current projects under construction include the 250 MW California Valley Solar Ranch project.

  8. Once installed, the 4.8 MW Bloom Energy fuel cell array will be the largest SOFC installation in the world.  While SOFC units can operate using natural gas, the iCloud data center installation will use renewable bioigas.  Per the U.S. DoE EERE, SOFC fuel cells have a typical efficiency of 60% and are best suited for distributed generation, auxiliary power, and utility-scale facilities.  Advantages of SOFC fuel cells include high efficiency, long-term stability, fuel flexibility, low emissions, and relatively low cost. The largest disadvantage is the high operating temperature which can result in longer start-up times and corrosion.  There are also some potential mechanical and chemical compatibility issues.  Bloom Energy believes it has met the challenge inherent in the high temperature SOFC fuel cell arena, producing a product that has high electrical efficiencies and fuel flexibility.  Other Bloom Energy installations of note include a 1.6 MW installation for Adobe and the installation of a total of 7.5 MW at (11) sites for AT&T.      

  9. References

  10. Apple:  Apple and the Environment


  12. ENR Southeast:  Apple Gets Boost From Sun for iCloud Data Center


  14. Waste Management World:  Apple to Build 5 MW Biogas Fuel Cell at Maiden Data Center



  1. Maiden, North Carolina, U.S.A.

Project Status:

  1. 2012 (expected completion)

Rated Capacity:

  1. Total:  24.8 MW

  2. Solar PV:  20 MW

  3. Fuel Cell:  4.8 MW

Annual Production:

  1. Total:  82 GWh per year

  2. Solar PV:  42 per year

  3. Fuel Cell:  40 GWh per year

Capacity Factor:

  1. Solar PV:  24%

  2. Fuel Cell:  95.1%

Carbon Offset:

  1. TBD


  1. Apple Computers


  1. TBD

Generation Offtaker:

  1. Apple Computers (Maiden iCloud Data Center)

Generation Technology:

  1. Solar PV:  SunPower E20 435-watt ground-mount monocrystalline c-Si PV panels with SunPower T20 single-axis tracking

  2. Fuel Cell:  (24) 200 kW Bloom Energy SOFC (solid oxide fuel cell) ES-5700 biogas fueled units.


  1. Unknown