US Navy Steams Ahead

July 31, 2014

The United States Navy-ever since its birth on October 13, 1775 when Congress voted for the fitting out of two sailing vessels-has always been at the forefront of innovative technology, including that which involves energy. The wind that powered those first ships is once again on the table as an important source of renewable energy. The Navy has also set the bar substantially higher with its goal of producing 50% of its shore-based energy from alternative sources by 2020.

The Department of the Navy (DON) also intends that 50% of their installations will be net zero. Net zero typically means no overall energy consumption and zero annual carbon emissions. In other words, even though some energy is used, the energy is from renewable energy sources, and no energy is purchased from the grid or external energy producers because the site involved produces as much energy as it consumes. The term “off the grid” comes into play.

The DON has additional short-term goals as well. These include the reduction of non-tactical petroleum use, and, by 2015, a 50% lower use of commercial vehicles. The Navy demonstrated a biofuel blend-powered Green Strike Group in 2012 and intends to sail it by 2016. The DON will also evaluate energy factors when awarding contracts for systems and buildings. This latter goal will be mandatory. These goals will require a much larger renewable energy generation capacity than has been in existence to date. As a result, the 1 Gigawatt Task Force came into existence.

Each region and installation is required to build an energy plan to achieve these and related objectives. Some regions and developments are even expected to exceed their own requirements. The Navy is concentrating on, and developing, solar (photovoltaic, thermal, and concentrated) installations, wind power wherever feasible, geothermal energy, biogenic, or waste (biomass, biofuels, waste-to-energy, landfill gas, and municipal solid waste), and even marine energy (wave, tidal, ocean thermal, Seawater Air Conditioning).

The DON realizes, as well, that efforts must be made to pursue development of smart microgrids for critical demand loads to support mission-enabling infrastructure, as well as to facilitate demand response (DR) techniques as requested by local utilities. As their “Strategy for Renewable Energy” points out: “The Department of the Navy must evolve beyond simply providing emergency generators for individual buildings to being able to provide reliable, sustained power to designated substations with the capacity to match sources to critical loads. As microgrids and smart grids are developed, renewable energy can be integrated along with other generation sources to provide diversified power as necessary to the installation’s critical assets.”

In the Navy
Energy savings in the DON consists of three pillars that make up the program, according to Bernie Lindsey, energy program manager at Navy Region Southwest. The Secretary of the Navy brought out these goals for the organization four years ago. The first of the three areas consists of improving the energy culture and changing behavior, encouraging people to understand the importance of wise energy. Second of the pillars is energy efficiency and improvements in buildings in such areas as lighting and HVAC controls. The third area is that of renewable energy and sustainability in the construction of buildings.

The Navy has recently done solar installations on rooftops. These have been 10 kW, all the way up to 100 kW. There are some 90 locations all around the Southwest Region with solar rooftop installations. They are also working on power purchase agreements (PPAs).

At the Naval Air Weapons base at China Lake, CA, there is a very large energy load and there was a great opportunity to install a large PV solar array. “Last year the switch was flipped on this system, the largest in the Navy, some 13.8 megawatts, 13,800 kilowatts,” explains Lindsey. “Just to put it into perspective, a typical home heating system might be four to five kilowatts. This system is spread over 120 acres and provides about 30% of the annual electricity requirement for that facility; the array is owned and operated by a contractor-developer, and they sell electricity to us. It’s a great example of the Navy pursuing larger renewable energy opportunities and it meeting a significant part of our energy demands. We are purchasing power from them for less than we were paying Southern California Edison.”

This allows the renewables industry to benefit from federal tax incentives in these projects while the federal government and the military leverage expertise. This puts the Navy’s projects on a level playing field with those outside the defense industry. It also puts the operation and maintenance into the hands of industry experts while the Navy buys the power at less than the usual rates. All around, this is an excellent arrangement for both the military and industry.

Lindsey says, “We’re going to be pursuing more of those types of contracts, as will other branches of the military service as well. This is a nice development and a way to showcase the good energy and cost-saving work that the Navy is doing.”

As far as microgrids, rather than jump in and spend a significant amount of money on a large microgrid involving a lot of circuits, they’re starting very small and getting to the heart of “What is the return on investment”, and “What are the lessons learned on obtaining more renewable energy?”

Lindsey says, “We are currently investigating and just entered into a new demonstration project funded by the Office of the Secretary of Defense. It’s a project in San Diego, and what we are doing with that initiative-a two- or three-year demonstration program-involves the taking of one electrical circuit at each of three installations, and then the installing of some equipment that does measuring and controlling of all three of those circuits. This is done so we can incorporate renewable energy into the microgrid, and another circuit that has energy from a cogeneration site. The idea is to operate a regional microgrid and do a fair amount of modeling and testing so that we can get lessons learned and be able to extrapolate and scale to a larger microgrid across the whole spectrum of the installation.”

The purpose of the Southwest Regional command is to oversee the operations of area installations. “We are focused on the environment, shore energy, and shore utilities. We are very interested in better ways of integrating renewable energy infrastructure into all those buildings with more controls. These should be more efficient and save money as well as time.”

Lindsey refers to this as a burgeoning, immature, and new area, though renewable energy is maturing as time goes by. “Prices are coming down; there are thousands of installations going on across the country, and that part of the energy industry is going where people have never been over the past decades. There are many more questions than answers right now-a lot that is undecided, and a lot of folks that are involved with various initiatives-there is great interest, but we are taking a cautious approach, because there are so many more questions than answers. We want to take an approach where we learn as much as we can, get lessons learned, and get things done the right way to make our installations smarter.”

Lindsey does not envision the entire installation being microgrid-connected, or the wholesale switching off from the grid in time of crisis. The infrastructure to do that is perhaps cost-prohibitive. “I don’t think it’s feasible to look at it from the scale of an entire installation; that’s a significant amount of power. We’re really focused on the microgrid concept of in the future: “˜How can we operate and meet the power requirements?’ In times of wildfire or other catastrophic events, we want to be able to meet the Navy mission, and something like a microgrid will be able to provide power to the most critical facilities at a time of crisis.”

Greening the Fleet
Gas turbines have powered ships in the US Navy for some 40 years. This was a big step up from the coal, steam, and piston engines that powered ships earlier in the last century. Gas turbines meant quicker reaction times and greater reliability and modularity, and they were far less cumbersome than the old steam vessels.

Today, gas turbine technology is mature and state of the art. Yet, each Navy ship operates within the limits of its design, and that includes a finite amount of fuel. Getting the most out of each drop of fuel on a ship is imperative, and that requires a culture of energy conservation.

USS Benfold (DDG 65) is an Arleigh Burke-class guided-missile destroyer based in San Diego, CA. Benfold’s commanding officer at the time of this interview was Commander Rich LeBron. When he and Benfold’s Chief Fire Controlman Christopher Roberts were asked about shipboard energy conservation, they said one tactic is competition among divisions on the ship, to see who can save the most energy.

“We are trying to keep our numbers as low as possible, the amount of fuel being burned per hour or per day,” says Roberts. “When in port, we go back to regular megawatt-hours. We use, essentially, a huge extension cord to obtain power for the ship from the pier.

“Energy consumption study is twofold: barrels of fuel per day when the ship is at sea, and then in port when we are measuring our megawatt-hours,” says Roberts. “We recently reached a 24.5% decrease in fuel consumption in the fourth quarter, the tail end of our deployment.”

LeBron says Secretary of the Navy Ray Mabus’ Great Green Fleet concept shows the Navy is serious about reducing fossil fuel consumption. “They’re demonstrating new technology, especially on the Air Force end of our fleet,” he says, “everything from the USS Makin Island (with its hybrid propulsion), to the biofuels that they’re using in aircraft now.

“From my perspective, I don’t care whether they’re pushing diesel; or cooking oil, biofuel, or a blend of diesel and biofuel. My goal is to reduce the consumption level of all fuel on board all ships. We’re focused on consumption rate. Part of what we also concentrate on is energy conservation while our ships are underway,” says LeBron.

“Although I’m willing to be drifting, with engines shut down to save fuel, our sensor systems are reliable enough that they have a tactical awareness of what’s going on around us. I’m comfortable that we can start the jet engines if need be, but in the meantime, we’re not burning fuel while at sea for no particular purpose. In the short term, our focus is on consumption rate, regardless of what the source of fuel happens to be,” he says.

The Navy commissioned a study of shipboard energy use in 2012, to identify opportunities for saving energy. That study included gathering detailed data on everything from lighting to overall pierside power consumption. The Navy also established a competition among ships to promote energy conservation.

Arleigh Burke-class destroyers typically draw approximately 1,800 amps, but Benfold got down to 1,147 amps at night when there is not as much activity going on onboard the ship.

“Using competition onboard was extremely effective and was how we managed to get down to a reduction in fuel consumption 25% below what is normal for ships in that class,” says LeBron. “Another thing we do for the ships is regular hull cleaning. This allows us to get through the water a little bit easier. We have a fuel efficiency burn rate based on how our routes are set up.

“If we have to go from point A to point B in a certain amount of time, we can calculate the best way to get the optimal fuel savings. These include speed, configuration of the ship’s movement … all of those things may be calculated and will allow us to decrease our burn rate. Shipboard energy plans are much more operations-based than at land DON installations; the equipment that you have is the equipment that you have. It’s how you use it that measures our effectiveness.”

Regular maintenance and keeping a ship clean helps it run as efficiently as possible. “One of the key takeaways from this entire process is that there is nothing that we really do on board that’s not reproducible across the entire fleet,” says Roberts. “It’s a matter of analyzing how any changes can be implemented and what the impact to the system might be, so that we can be as efficient as possible. We’re not unique in any way. It’s just a matter of how we are operating our equipment, keeping it clean and well-maintained. This means it is operating more efficiently and costing us less fuel in the end.

“It doesn’t really matter what we’re talking about, in the end it all translates to fuel consumption rate. It typically costs 4,900 dollars per day to operate a ship in port,” says Roberts. “When we operate ours, we are at about 25% below that rate, saving 1,000 dollars per day. People don’t understand how much it costs to operate a ship and how much our efficiency matters, the savings that can be accrued.”

In addition to inter-ship competition, the Navy does have awards for the top energy saving installations based on such criteria as large commands, small commands, and various details about specific facilities.

Tapping Freely Available Energy Sources below the Surface
The Department of Defense (DOD) participates in geothermal development activities, in particular as an end user. In 1978, DOD established the Geothermal Program Office (GPO) and designated the US Navy as the lead agency responsible for geothermal exploration and development on military lands. The DOD GPO manages 32 million acres of land.

GPO has helped develop geothermal energy projects for the military as end user at a variety of locations in the western US, including in California, Nevada, and Arizona. They include those in California at the Naval Air Weapons Station China Lake, the Naval Air Facility in El Centro, the Marine Corps Air Ground Combat Center in Twenty nine Palms, those in Nevada at the Naval Air Station in Fallon and the Hawthorne Army Depot in Hawthorne, and the one in Arizona at the Chocolate Mountains Aerial Gunnery Range at the Marine Corps Air Station in Yuma. This section includes additional information on three of these projects, most notably the long-running and successful Coso Geothermal Field at China Lake.

The Naval Air Weapons Station China Lake is the Navy’s premier weapons testing and evaluation base. It is located in California’s Mojave Desert and encompasses a geological formation known as the Coso volcanic field. GPO worked with private investors to develop geothermal energy at this site. Despite the geographic proximity to active bombing ranges, the Coso geothermal field has been successfully producing electricity since 1987, without interference to base operations.

Initially brought online with 30-MWe capacity, the geothermal facility was expanded over time to include nine turbines in four separate power plants with a combined nameplate capacity of 270-MWe. This expansion has made the Coso geothermal field the third largest in North America.

The Coso field continues to produce geothermal power with a 98% capacity factor and a record annual production of 2,329 GWh in 2,000. Revenue from the sale of power at Coso funds all of the work of the GPO, as well as other Navy energy programs. Furthermore, ongoing and planned geothermal exploration and development activities by GPO supports the DOD goal of producing 25% of energy used on DOD installations from renewable resources by 2025.

In 2005, GPO signed a development and production contract with Ormat Nevada Inc., a subsidiary of Ormat Technologies Inc., to develop geothermal energy on Federal lands that include a portion of the Fallon Naval Air Station in the Nevada desert approximately 60 miles east of Carson City. The agreement followed discovery of multiple geothermal indicators in the southeast corner of NAS Fallon, and it gave Ormat through the end of 2011 to develop the resource, complete all construction, and generate power.

As noted already, DOD has a goal of producing 25% of energy used on DOD installations from renewable resources by 2025. In meeting this challenge, GPO has proposed that military installation energy needs should also include integrated solar energy into any potential geothermal energy production portfolio. Such a “hybrid” geothermal program could greatly expand the amount of energy produced right on the base grounds.

One example of such a hybrid system is at the Coso facility, where Terra-Gen plans to construct a 1-MWe concentrated photovoltaic pilot plant to test the efficiency and cost effectiveness of this type of system. Ideally, such a system could augment parasitic load losses in a geothermal plant and considerably add to the peak energy demands of the installation or the local buyer of this power.

The world is vastly different place than it was in 1775, when the nascent US Navy obtained its first vessels, ones relying solely on often-present and renewable wind power. Wind (though not really touched on in this article) has never gone away, and all of the other freely available renewable energy sources are on the table, ready to sail the DON into the middle of this century and beyond as the Navy saves fuel, money, and the environment with its efforts.

About the Author

Peter Hildebrandt

Peter Hildebrandt writes about construction, technology, and industry.

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