The Greening of the Data Center

Carl Weinschenk spoke with Peter Rumsey, P.E. and founder and president of Rumsey Engineers.

Weinschenk: What do people mean by "green" buildings?
Rumsey: Green is a term that is loosely thrown around that portrays the environmental impact of a building in the commercial sector, for office buildings or homes. A green building is a building that addresses different categories of environmental impact, things like transportation, whether it is a polluted site, the water impact of the building, what kind of materials are used, the indoor environmental quality and if it is healthy for occupants. The last category is energy consumption. That is a big environmental problem right now, connected to global warming. It may be the single most important challenge of the twenty-first century.

Weinschenk: What special issues pertain to data centers?
Rumsey: A data center is anywhere between 100- and 200-times more energy intensive than a home or an office on a per-square foot basis. … So the environmental impact of data centers by far is dominated by energy use. So when people say they use recycled materials in the data center, I actually laugh. It's not the point in the data center. The point is the energy. There is a U.S. Green Building Council which has developed "LEED," which stands for Leadership in Energy and Environmental Design. It's a green building rating system consisting of a whole series of points. You get points for saving water; if you lower energy use, you get points. Then if you get enough it can be a certified building. There are certified silver, gold and platinum levels. So if you take the data center and use the LEED rating system and use that to say, "Okay, I have a green data center," again, that's just the wrong way to look at it. Most people in the data center business do this. Green data centers use less energy, that’s what it is all about. The energy use of the data center, from an IT perspective, is the key.

Weinschenk: What about the equipment itself?
Rumsey: We have servers that are so small and dense and it is very difficult to provide enough cooling to the rack. Data centers want the latest generation of servers but can't use them because there is not enough electrical power and not enough cooling. So IT people say, "Oh my, the power consumption of servers is up so dramatically and there are so many in the data center that energy is the bottleneck." The wonderful thing is that if we lower energy consumption, we can put in a lot more servers, lower out energy billing and, oh yes, we can claim that we have a green data center. So there's kind of a triple win: capacity, dollar savings and green benefit. Everybody is thinking green data centers and green computing from different angles. The key is if computer suppliers get onboard or are left behind. If the devices use so much power, they are not going to sell. There's a competitiveness thing that has to happen here.

Weinschenk: What is the incentive to build more energy-efficient gear?
Rumsey: Let's talk about energy from the dollars perspective. I was at a conference recently of people from larger manufacturers. What they are saying is that now if we take net present value of a server's electrical and cooling energy over the three-year life of the device and compare it to the purchase price of the server they are almost equal. If trends continue on energy … there will be a point in the near future where energy costs more than the server costs. That’s a really big deal. In the past, IT people purchased whatever had good performance … So they would select the best performing service and the best price. Now suddenly IT guys have issues about the energy levels of the facility and the infrastructure in it. They have got to take that all into consideration.

Weinschenk: Are people thinking differently?
Rumsey: Here's the logic. The data center space in collation facilities and construction thinks dollars per square foot. In collocation facilities, companies lease a cage. … All the pricing is based on square feet. ... Actually, the paradigm needs to change. It should be charging for power, not for square footage. That's what data centers are about, providing power and cooling in a reliable way. Some of the more sophisticated people in the data center space understand that we need to charge for power, not just for square footage. In the future, the dynamic won't be so much on compaction, but now there is compaction pressure.

I'd like to think that we are working in one of most innovative industries on the planet. I think this industry can move on a dime when it comes to adopting new technology, new chips and new protocols. However, interesting cooling and infrastructure is a different discipline. The building people in the U.S. are very slow to adopt technology. They are conservative. It is all about providing incredible reliability, and they are quite conservative.

Weinschenk: Where are the end users — the tenants — in all this?
Rumsey: It's changing right now. Now, a bottleneck occurs and they can't put any more gear in the data center. The CIO finds out from the facilities side of the house that they have no more power. So people are starting to realize. I still see some "green washing" and hype, but when I go to conferences there is a growing group of people who are talking about lowering energy use.

Weinschenk: How do you reduce the energy used in a data center?
Rumsey: There are two ways to attack energy problems. Both need to be used. The first and most important is the IT equipment itself. There is a need to lower energy use of the equipment. The other is on the building side.

Weinschenk: Let's look at the equipment first.
Rumsey: The core of the issue is that IT equipment is energy intensive. We need to focus on that. There is not one technology that solves the problem. There are a lot of steps to be taken. For example, there are power supplies, and the processor types. One good step is to use dual-core, quad-core and multiple-core processors. On a performance basis, they have lower power consumption. As an example — not to focus on Sun — but the Sun T1000 and T2000 servers use eight-core processors that are quite energy-efficient. Power performance is very good.

Weinschenk: What steps are being taken to reduce the need for energy in the buildings?
Rumsey: IT equipment uses half the power. The UPS power and cooling is the other half. We need to address that and get it down to the point where three-quarters of the power goes to IT equipment and one-quarter to the facility.

The vast majority of the building's energy goes to cooling. We are working on a wide variety of technologies to reduce cooling dramatically. Two major strategies fit into the category of economizer cooling. If it's hot inside the building and cold outside, let's open the windows. The way you implement the concept is to get air handlers that can filter, humidify and use that air. Even in places that are hot and have a humid climate there are a lot of times the data center can do this, such as in the winter and nighttime. In New York State, they use outside air in cooling. In the hot summer months, it is not applicable. In winter and spring, it is very applicable. Google is setting up its servers in Oregon. Two of the reasons are that energy is cheap and it's cold. The other way is a strategy called waterside free cooling, or waterside economizer. It involves a cooling tower with a chiller. If it is a cold day, you turn off the chiller and use the cooling tower to make the cold water directly usable in cooling the coils.