There are arguably many ways to get to 100% green power for a data centre. You can put it where all the power generated is green, such as in Iceland. Or you can buy RECs, renewable energy certificates, to offset all the electricity you get from the traditional grid.
But Apple has embarked on an ambitious, and far from easy, task of building a new data centre in Maiden, North Carolina, that will be powered by 100% green energy, and not by any of the aforementioned methods. Instead, Apple has laid out a blueprint that combines a number of initiatives, including on-site generation, energy efficiency, and renewable energy sourcing, to achieve its 100% green goal.
The plans are significant, because it effectively represents the first 100% green data centre in more or less real world, albeit perhaps financially distorted, conditions – since Apple has the money to build a facility from scratch and to acquire enough land to build its own solar farm.
In terms of onsite generation, Apple says it will be able to generate about 60% of the projected 20MW needed to power the data centre from its own solar farm.
“We’re currently building two solar array installations in and around Maiden. These sites use high-efficiency solar cells and an advanced solar tracking system,” the company said on a dedicated page on the project. “A 100-acre, 20-megawatt installation on the same site as our data center will produce 42 million kilowatt-hours (kWh) of energy annually. A 100-acre site located a few miles away will produce another 42 million kWh. Together that’s 84 million kWh of clean, renewable energy supplied annually. When our bio-gas-powered 5-megawatt fuel cell installation comes online later this year, it will provide more than 40 million kWh of renewable energy annually. This means Apple will be producing enough onsite renewable energy — 124 million kWh — to power the equivalent of 10,874 homes.”
Obviously, not many companies out there can easily justify the purchase of 200 acres of land and the solar panels to fit them out, but what Apple’s project represents is a proof of concept that such an endeavour is possible.
Direct access green power
But Apple doesn’t stop there. To power the remaining 40% of the Maiden facility, Apple will seek renewable energy from third party supplier. But instead of simply going out and buying RECs, which does not necessarily mean the power it is buying is from green sources, simply that an equivalent amount of green power is being generated somewhere, Apple is very specific about how it is going about buying green power.
According to Apple, it will be “directly purchasing clean, renewable energy generated by local and regional sources.” This is a paramount phase because it means that Apple will be buying energy that is in fact generated by renewable sources such as wind, solar, and bio-gas. Also, the fact it specifies ‘local and regional sources,’ means that it is supporting local green power initiatives, and consuming what is generated. This also minimises any losses to the power during long distance transmission.
“Directly purchasing clean local energy gives us the flexibility to meet our needs over time, helps us to ensure that our sources are reputable and responsible, and encourages local investment in renewable projects such as wind, solar, and bio-gas power in locations best suited for these resources,” the company said. “Adding renewable energy sources like these displaces dirtier energy sources from the grid. We’re also partnering with NC GreenPower — an independent, nonprofit organization created by the North Carolina Utilities Commission — to increase local renewable energy production throughout North Carolina. Today Apple’s largest project with NC GreenPower is helping the local landfill in Catawba County (located just three miles from the Maiden data center) to generate electricity using their waste methane gas.”
In addition to relying entirely on renewable energy, Apple will also minimise the energy requirements of the Maiden facility through a number of energy efficient measures. These include the use of a chilled water storage system to improve chiller efficiency by transferring 10,400 kWh of electricity consumption from peak to off-peak hours each day, the use of ‘free’ outside air cooling through a waterside economiser, a precision cool air distribution system, and cold air containment pods, a higher voltage power distribution to lessen losses, efficient LED lighting with motion sensors, and real time power monitoring for maximum efficiency. Apple has even gone as far as to put in a white roof to maximum solar reflectivity.
What’s important to remember is that each of these things are necessary parts to achieving Apple’s goal and each will take a lot of work, in terms of man hours, investment, logistics, operational complexity, and no doubt many other elements. Those are the challenges. That’s what it will take to get to zero carbon emissions for the data centre industry.
For Apple’s part, the Maiden site is not its first 100% green site. According to the company, its operations centres in Austin, Texas, Sacramento, California, and Cork, Ireland, as well as its Munich, Germany facility are also zero emission sites.
Apple is also planning to green two more data centres, a new one in Prineville, Oregon, and an existing site in Newark, California. For these sites, Apple will rely primarily on local direct access renewable energy.