Category: Energy

Internet Data Centers & Energy-Efficiency

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Internet data centers are fast becoming the largest power hogs in the world. What’s being done in this industry to make Internet usage more energy-efficient?
—M. T., Reno, NV

Though our online activity uses no paper, it still consumes quite a lot of energy. Data centers account for much of this energy use. These warehouse-sized buildings contain arrays or “farms” of servers, which are essentially souped-up computers that have many uses, including storing data and supporting all the activity on the internet. They are the hardware behind the proverbial “cloud.”

Data centers like this one use up lots of power; that’s why environmentalists are urging the biggest players in the industry to go with renewable energy sources where possible. Credit: CommScope.

Like the personal computers we all use, servers require electricity to function. Since internet users can call upon them to provide information at any time, they must remain on 24/7. Furthermore, as with any form of electrical activity, the functioning of this large number of servers packed together in a small area can result in overheating, making the need for cooling an additional energy cost for data center managers.

According to data center provider vXchnge, U.S. data centers alone use over 90 billion kilowatt-hours of electricity annually—about what 34 coal-powered plants generating 500 megawatts each produce. ComputerWorld magazine reports that the energy consumption of data centers worldwide will likely account for 3.2 percent of global carbon emissions by 2025—about as much as the airline industry—and as much as 14 percent by 2040.

In light of all this, finding ways to cut energy use has become a big priority in the industry. One of the simplest strategies is to locate data centers in cool climates, and use outdoor air to counter excessive heating. Alternate options include cooling inlet air by running it underground, or using a nearby water source for liquid cooling. Another issue is separating hot air produced by servers from the colder air used to cool them—no easy task if the servers are all housed together. But there are plenty of cheap solutions. Google, for example, uses low cost dividers from meat lockers for this purpose.

Another way data centers can reduce cooling costs is to design servers that can operate at high temperatures without overheating. Recent research shows that servers can operate at much higher temperatures than initially believed without compromising safety or efficiency. But not all data centers are comfortable letting their servers run hot. Other ways to make server farms more efficient include optimizing grid-to-server electrical conversions and reducing the energy required by “sleeping” servers.

The good news is the industry is making strides in the right direction. Apple, Facebook and Google all power 100 percent of their data center and other operations with renewables, albeit through the purchase of “renewable energy credits” akin to carbon offsets that air travelers can buy to keep their carbon footprints in check. Microsoft is moving toward 70 percent renewable energy by 2023, while laggard Amazon still only gets about half its data center power from renewables. And Switch, one of the largest U.S.-based data center companies, transitioned all of its facilities to run on nothing but renewables in 2016, including the nation’s largest data center in Reno, Nevada.

CONTACTS: “How to Improve Data Center Power Consumption & Energy Efficiency,” “Why data centres are the new frontier in the fight against climate change,” “Amazon is breaking its renewable energy commitments, Greenpeace claims.”

EarthTalk® is produced by Roddy Scheer & Doug Moss for the 501(c)3 nonprofit EarthTalk. Send questions to: question@earthtalk.org.

Perovskite-Based Solar, Q&A With EarthTalk

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What is perovskite-based solar all about, and how does it differ from silicon-based solar?                                             
–Mary W., Baltimore, MD

No doubt, solar power has been growing rapidly, with a 28-fold increase since 2009. This expansion has been driven mainly by a massive reduction in the cost per kilowatt of solar-generated electricity. In many regions, it’s more economical to set up solar arrays than it is to create new coal or natural gas plant. But how much further can we really take solar given that we’re already maxing out the efficiency of our panels and many regions of the world are still too dark to take advantage of them accordingly?

Perovskites: Researchers at the University of Oxford in the UK are experimenting with perovskites as the semiconductor in these small tin solar cells that could someday be on your rooftop supplying your home with free electricity. Credit: University of Oxford Press Office FlickrCC.
Researchers at the University of Oxford in the UK are experimenting with perovskites as the semiconductor in these small tin solar cells that could someday be on your rooftop supplying your home with free electricity. Credit: University of Oxford Press Office FlickrCC.

One answer might be perovskites. This calcium titanium oxide crystal found in the Earth’s mantle can be used instead of silicon as a semiconductor driving the capture and transmission of energy from solar rays to electricity. There are many different types of perovskites, but they all share the same general molecular structure. Recently, materials scientists have been working on ways to harness their unique electrical and photovoltaic properties to boost the efficiency of solar collection. They see this as an imperative, given that our current crop of silicon-based panels top out at only 20 percent efficiency in ideal conditions, and that’s after decades of research and development to optimize them.

In 2009 when research in perovskite-based solar was just beginning, panels made with the crystal showed efficiencies of around four percent. By 2018, researchers boosted this number to 24 percent. No other type of solar technology has seen an efficiency jump of this magnitude in such a short amount of time.

Several other properties add to the appeal of perovskite-based solar cells. They are relatively easy and cheap to produce and are suitable for use in applications that silicon-based panels aren’t. Perhaps most important, they can generate electricity using wavelengths of light that most of our current commercially available panels can’t harness. Researchers envision a future where perovskite panels are actually fused into a layer on top of traditional silicon panels. In this tandem application, perovskite panels would capture part of the incoming light while the rest shines through for the silicon panels below.

Despite the promise of perovskites, there are still many hurdles to overcome before they can become a viable large-scale option. One is lifespan: Silicon-based panels last between 25 and 30 years, while perovskite versions created in the lab only last a year at most. Another issue is scalability. The high efficiencies in perovskite cells that scientists have observed have only been achieved on very small (“postage stamp” sized) panels. On larger perovskite panels, the efficiencies have been much lower. The final big obstacle for perovskite researchers to overcome is toxicity. At the moment, high-efficiency perovskite cells can only be made using relatively toxic compounds, such as lead. While less toxic versions exist, they are also less efficient.

Daunting though these challenges may be, many bright minds are working to solve them. While solar power’s future is by no means certain, it is looking increasingly like this powerful little crystal will play a major role in bringing sun-derived energy into the mainstream market.

CONTACTS: Worldwide Renewable Energy Forecast 2019; Rise in Perovskite Research 2011-2015.

EarthTalk® is produced by Roddy Scheer & Doug Moss for the 501(c)3 nonprofit EarthTalk. Send questions to: question@earthtalk.org.

Oil & Gas Pollution on Pennsylvania Public Lands

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All of Pennsylvania’s oil and gas facilities–whether unconventional (aka “fracked”) or conventional, and uncounted abandoned wells–have the potential to emit both methane that harms the climate and toxic air pollutants that impact air quality and harm health. Earthworks’ investigations of oil and gas development in Pennsylvania’s State and National Forests shows that the industry benefits from weak regulations and limited enforcement, allowing them to emit serious pollution and present other problems that degrade our public lands.