Solar power is cheap, at least when compared to other renewables, like geothermal. It’s clean. It’s fast to install. Given these advantages, why aren’t solar-powered data centers more common in the industry?
The short answer is that data centers are increasingly incorporating solar power, but they’re still a minority. The longer answer, which this article explores, involves the unique opportunities and challenges that solar energy presents in the context of data centers.
The State of Solar Power in Data Centers
Solar power, of course, is a type of energy source that uses the sun to generate electricity. Its history dates all the way back to the 19th century, although improvements in the energy conversion rates of solar panels have made them much more efficient in recent decades. Prices have also steadily decreased, boosting the cost-effectiveness of solar energy and, potentially, solar-powered data centers.
These trends have led some data center operators to adopt solar as an energy source. Although it’s unclear exactly which percentage of data centers currently use solar, many large data center operators have invested in solar. Some have done so by partnering with utility companies, such as Dominion in Virginia, on projects that add solar capacity to the grids that support their data centers. In other cases, companies that operate data centers have built their own solar farms.
It’s easy to understand why data center operators would be attracted to solar power. Solar is a relatively inexpensive renewable energy source. The more electricity data centers can acquire from solar, the lower their carbon footprints will be. Solar is also often faster and easier to install than more complex types of renewables, like geothermal generators.
Data centers’ enormous electricity consumption necessitates vast solar infrastructure, creating a significant barrier to fully solar-powered facilities. Image: Alamy
The Challenges of Solar-Powered Data Centers
Overall, the use of solar power as a power source for data centers remains limited. No major data center operates using solar power alone, and it’s hard to imagine one doing so in the foreseeable future.
That’s because solar presents several special challenges for data centers that appear impossible to overcome definitively.
1. Limited Power Capacity
The biggest obstacle to solar-powered data centers, perhaps, is that data centers consume a lot of electricity, and individual solar panels produce relatively small amounts of energy. As a result, you need a very large expanse of solar infrastructure to supply adequate energy to a data center. By one estimate, a 100 MW data center would require about 1,446 acres of solar panels if it were powered by solar alone. Admittedly, a 100 MW facility is a large one. Smaller data centers would require a smaller “solar footprint”.
But either way, data centers require a massive solar infrastructure relative to their size. Acquiring enough land to install the solar panels necessary to power a data center is tough. In addition, clearing large expanses of wild land and filling them with solar panels can give rise to concerns that solar does more harm to the environment than good.
2. Intermittent Solar Power
Another obvious downside of solar power is that it only works when it’s sunny outside. It’s not sunny overnight, and it’s not sunny when the sky is cloudy. This means that it’s always necessary to supplement solar with other energy sources.
Theoretically, it could be possible to power a facility using solar alone by collecting excess energy on sunny days and storing it in batteries for use when the sun goes away, but the cost of batteries makes this impractical as a way to supply the vast quantities of energy required by data centers.
Solar can be more viable in regions like the southwestern U.S., where some areas see sunshine for as much as 90% of a typical day. It’s less feasible in climates where overcast skies are the norm for much of the year.
Unfortunately, data center operators don’t usually have the luxury of being able to choose where to locate a data center based on how sunny it is. They have to consider factors like land affordability and the availability of network infrastructure. As a result, many build facilities in areas that are just not good candidates for solar power.
3. Intermixing of Power on the Grid
The nature of electrical grids makes it challenging to power a data center with solar, specifically. Most power grids generate energy using a variety of sources, including renewables and fossil fuels, and effectively mix them together before delivering them to customers. There’s no way to guarantee that all the power supplied to a specific data center or other building will come from a particular source.
So, when data center operators partner with utility companies to add solar power to the grid, they’re not really fueling their facilities with solar power directly. They’re just increasing the overall percentage of all energy that comes from solar.
Powering a data center with solar directly would require building a private power plant or grid – a prospect that is expensive and logistically challenging for most data center operators, who are not in the electricity generation business.
The Future of Solar Power for Data Centers
As the cost of solar energy infrastructure continues to decline and as data center operators face sustained pressure to reduce their carbon footprints, solar will likely become increasingly attractive as one way to decrease reliance on traditional energy sources. However, the inherent limitations of solar make it difficult to power data centers primarily using solar, and these challenges do not appear to be solvable through technological innovation.
So, we should expect to see more investment in solar by data center operators in the coming years. But don’t expect solar to revolutionize the way we power data centers.
