I met Chris Martin when we were sketching out the IT architecture for embedded systems on the UNC campus. He would sit quietly at the edge of the conversation, smile, and occasionally lob a penetrating question over the assumptions of the discussion. His quiet good humor overlaid a flexible mind to strop my arguments on. In an abstract way, I considered him an ally in the overall efforts, but like many co-workers, I didn’t really know much about him.
I did know that his mind grappled easily with distributed reliability, and DC houses, and microgrids. This week, I learned of what he described as his first real job as an engineer. He had worked in Antarctica, installing the power systems for the Black Island Telecommunications center
Black Island is home to the telecommunications center for Antarctica. Its conditions are bitter cold, and isolated. The center’s energy needs are large, unceasing, and growing. Because McMurdo Station, the primary Antarctic camp, has all satellite communications blocked by Mount Erebus, all communications are routed through Black Island.
It is beyond difficult to bring supplies and fuel in. The Telecommunications Center is only accessible by helicopter or a dangerous two-day traverse over the Ross Ice Shelf. A traditional approach would have been diesel generators, but the difficulty of refueling the site made that option undesirable as the primary fuel.
The Black Island microgrid was designed to minimize the run-time and fuel use, and thereby reduce maintenance and supply costs, while providing for the constant high energy needs of running the station.
The first microgrid at Black Island was a couple wind turbines to charge the 24 volt DC power supply that the communication system runs on. The generator only ran when the batteries started to get low and wind was not running. Over time, t he power requirements of the Black Island have steadily increased; along with expanded MacMurdo communications, the site now also supports a NASA tracking station. The site now runs on 3 wind turbines, a photovoltaic array, and three diesel generators.
In some ways, the photovoltaic array is the most interesting aspect. In a site that gets full sun for only three months a year, and is in complete darkness for several months, photovoltaic generation might seem like fashion trumping sense. Actually, in a location where fuel handling and delivery are expensive, the additional reliability and flexibility added by another type of power generation, as opposed to a fourth turbine, increases the reliability and economy of the entire installation.
Black Island offers horrible conditions. The demands of the communications systems for reliable power are immense; maintenance is difficult and expensive. The site is in absolute darkness for months at a time while the temperature hovers around negative 70 degrees Fahrenheit. This site is far more demanding than any home or office. Still, with large power demands, fierce conditions, and little opportunity for maintenance, the installation has had essentially no downtime since 1985 while maintaining the highest standards of low environmental impact.
In science, the exception proves, or tests, the rule. In law, hard cases make bad law. In engineering, difficult and unusual demands bring out the greatest creativity, as every assumption and rule is challenged. Black Island does not look like a home, or even an office. Black Island does point the way to reliable power in the home and neighborhood.
Microgrids let the home, or office, or even neighborhood or office park, find a path to local clean power, even enough for today’s high-tech appetites. Using a variety of generation strategies, chosen for the site and its special demands, provides robustness. Generators, and their messy hydrocarbon storage and regular maintenance are the fly in that ointment. Transactional grid purchases guided by live pricing can replace the local generator in many cases. What is left is clean reliable power, immune to shocks on the larger power grid, while still using the power grid to enhance reliability, when the price is right.