☀️ Solar
Solar energy offers low operating costs for data centers after initial setup, but there are disadvantages. Solar panels require a large number of cells to power even a small data center, and installation costs may not be worth the investment. They only generate power when the sun is out, making them more suitable for warm areas than snowy ones.
To operate continuously, data centers would need significant battery storage, which is still developing. A 2019 Vertiv survey found that data center operators expected solar to provide 13% of their power by 2025. Until battery technology improves, solar energy alone is unlikely to be cost-effective.
🌬️ Wind
Technology is advancing rapidly, with average capacity levels increasing by 40% in recent years, primarily due to the deployment of larger turbines. Concurrently, the overall costs of wind projects have decreased by around 40%.
The plentiful supply of wind, especially in offshore locations, positions it as one of the most promising alternative energy sources. The Global Wind Energy Council (GWEC) has projected that wind energy could meet 20% of the world’s electricity demand by 2030.
🌋 Geothermal
Geothermal energy, sourced from hot water deep beneath the Earth, is renewable, consistent, compact, and widely available. It’s considered the cheapest renewable energy source and can also be used for cooling.
However, the U.S. Department of Energy (DOE) estimates that only about 0.7% of geothermal electricity resources have been utilized in the U.S., making it the least-used renewable energy source. Despite this, projections suggest geothermal energy could rise to around 50,000 gigawatts by 2050.
For data center operators, it may be wise to let hyperscalers explore this technology without making immediate commitments.
🌾 Biomass
Biomass was the largest source of energy consumption until the mid-1800s, primarily through the burning of wood. It converts organic materials into energy through various processes, including burning, thermochemical, chemical, or biological processes.
While biomass can help divert certain types of waste from landfills, sourcing suitable materials can be costly, and it requires significant storage space for organic materials outside the growing season. Due to these factors, biomass is unlikely to become a major alternative energy source for data centers in the near future.
💧 Hydropower
The benefits of hydropower include its low cost, cleanliness, and reliability. It can provide a stable power supply to complement intermittent sources like wind and solar, and the output can be adjusted by releasing more water from reservoirs.
However, hydropower isn’t without drawbacks. The dams needed for turbines can disrupt local ecosystems, and the high upfront construction costs make it impractical for individual data center owners.
⚛️ Nuclear
Small Modular Reactors (SMRs) are emerging as a reliable energy solution for hyperscalers and AI data centers. SMRs provide consistent and large-scale energy output with a small footprint and low carbon emissions.
While there are challenges related to radioactive waste management and public safety perception, nuclear energy plays a significant role in a low-carbon energy future.
🟢 Green Hydrogen and Fuel Cells
Green hydrogen and fuel cells represent a promising future for achieving a sustainable energy solution. Green Hydrogen is produced through electrolysis of water using renewable sources of power (like hydro, wind or solar) resulting in Hydrogen gas without carbon emission.
Fuel Cells on the other hand are devices that convert chemical energy from hydrogen directly into electricity without emitting any greenhouse gases. Typically, a Fuel cell consists of an anode, cathode, and an electrolyte. As the protons move through the electrolyte to the cathode, while electrons flow through an external circuit, electricity is generated.
Although hydrogen has a very high energy content, approximately 33.33 kWh/Kg, yet the actual usable energy conversion will depend on the efficiency of the electrolysis, fuel cells, and the operating conditions. The two most popular systems are Proton Exchange Membrane (PEMs) with around 40-60% efficiency and Solid Oxide Fuel Cells in the range of 60-80% particularly when combined with heat and power (CHP) applications.
🔋 Batteries
Batteries are becoming viable alternatives to diesel generators for backup power, thanks to two significant developments. First, the cost of grid-scale battery farms has dropped dramatically, with the U.S. Energy Information Administration (EIA) reporting a 72% decrease in project costs from 2015 to 2019. By the end of 2019, there were 163 large-scale battery storage systems in the U.S., totaling 1,688 megawatt-hours, a 28% increase from the previous year.
Battery storage is now seen as a practical option for short-term power needs. However, concerns remain about their effectiveness during long-term outages. The EIA anticipates that future battery projects will be increasingly integrated with utility power plants.
In the short term, batteries are best used to complement existing uninterruptible power supplies (UPS) rather than replace them. This approach allows operators to shift towards cleaner energy while maintaining a reliable backup system.