Ship acquisition affordability is a prime strategic focus for the United States Navy. The growing concern over the stability of the global energy market and the availability of energy
stresses the need to address energy consumption – specifically fossil-fuel based energy – of companies that build Naval ships. Geopolitical instability, climate change, long-term supply, and the threat of natural disasters all contribute to problems associated with the supply and demand of fossil fuels. Manufactures of equipment for the Navy have recently been hurt by the increases in energy pricing. Recent spikes in fossil fuel costs have caused budgetary problems for Navy shipbuilders, their subcontractors and industry in general which highlights the need to lessen the impact of energy costs fluctuations on Navy shipbuilding. As a leader of technology solutions, the U.S. Navy’s Manufacturing Technology (ManTech) Program will work with it’s industrial partners in the shipbuilding industry to evaluate alternative energy sources, and efficient manufacturing practices to lower manufacturing costs, and energy usage.

Figure 1-1 shows the demand for US energy by sector and source. In 2008, the industrial sector accounted for approximately 20% of the total United States consumption with petroleum and natural gas accounting for over 80% of the supply. In the early 1970s, the U.S. started transitioning away from heavy industry and towards the commercial and service sectors. This has contributed to slower energy consumption growth in the industrial sector compared to that in other sectors of the U.S. economy. However, the industrial sector still remains the largest end user of energy. Reducing energy consumption in energy-intensive manufacturing industries offers opportunities for improving environmental performance as well as reducing operational costs in an increasingly competitive global economy.

The current strategy by many large industrial companies, including many shipbuilders, is to manage demand by conservation. There are many immediate short-term steps that these industries can implement in their manufacturing processes which will cut energy consumption. Most of these steps involve regular maintenance including equipment repair, replacing leaky air lines to pneumatic tools, changing air filters, and reducing the air pressure to the minimum requirement for the tool. Other improvements include converting to energy efficient lighting, installing timers on thermostats, and insulating equipment such as hot water heaters. Changes in the manufacturing process could include the replacement of old air compressors with new, more efficient, multi-step compressors with improved system controls. Reducing the amount of air lines needed can also reduce costs by reducing set-up and break-down times as well decreasing the possibility of leaks. This could be accomplished by the use of more efficient portable hand tools that do not necessarily need to be connected to a fixed power source.

These improvements to the manufacturing process could be implemented immediately without the aid of any new technology. However, this approach alone may not achieve the proposed cost reductions. What is needed is a comprehensive approach to the reduction of energy usage in a complex industrial environment that will involve new technologies in manufacturing processes, renewable energy, as well as conservation. These approaches will not only help to conserve what energy is used, but it will also help insulate companies from dramatic price swings due to the instability of the energy markets.

One major area that needs to be explored is the use of alternative energy sources such as wind, solar, and wave power. These are available now and look to become more efficient and affordable in the next decade. However, these technologies require investment not only in development, but also in the commercialization of that technology for use on a large industrial scale.

Solar energy, both photovoltaic (PV) and passive, has been in use for a long time. PV solar energy takes light energy in the form of photons and converts it to electric energy through a solar panel. Photovoltaic cells are semiconductor devices (usually made of silicon) which contain no liquids, corrosive chemicals, or moving parts. They produce electricity as long as light shines on them, they require little maintenance, do not pollute, and operate silently. Passive solar energy relies on the sun to directly heat water or a building without any energy converting equipment. Commercial passive solar water heaters have been in use since the 1890s, but have diminished with the advent of cheaper more reliable fuels. PV solar increased in popularity in the 1970s during the OPEC oil embargo, but then declined due to the drop in fossil fuel prices in the following decades [1]. One success story in the use of PV solar power, is Federal Express [2]. A solar array on the roof of their Oakland, California hub (Figure 1-2) generates a maximum of 904kW and covers 80% of its peak energy needs. However, most solar energy is used only as a supplement to other conventional types of energy. Problems with start up costs, cloud cover, geographical location, and the large area needed for a sizable return have slowed the adoption of PV systems.

Commercial wind energy has also seen a large increase in demand. Wind energy derived from small sources, such as residential wind mills, are generally less than 10 kW systems and are not suitable for industrial applications [3]. Global wind capacity increased almost 29% in 2008, ending the year at 120,798 megawatts. This growth rate exceeded the annual average of the past decade. In 2008, wind machines in the US generated a total of 52 billion kilowatt-hours, about 1.3% of total US electricity generation. The wind now generates more than 1.5% of the world’s electricity, up from 0.1% in 1997. Eighty countries are now using wind power on a commercial basis with the US passing Germany as the top producer of electricity from wind power [4].

Recently a number of technologies have been developed to extract energy directly from the surface motion of ocean waves or from pressure fluctuations below the surface. This is done on a commercial scale in two ways. One method uses point absorbers that have components that move relative to each other due to wave action (e.g., a floating buoy inside a fixed cylinder). This relative motion is used to drive electromechanical or hydraulic energy converters. The other method is an actuator system where two floating cylinders are connected together by hydraulic pumps that convert the up and down motion of the waves to electrical energy. Agucadoura, the world’s first wave farm built off the north coast of Portugal, is such a system (Figure 1-3). This wave farm has three Pelamis wave energy converters that currently produce a total of 2.25MW. Plans are now underway to increase Agucadoura’s capacity to 21MW [5]. These types of systems have the advantage of generating almost continuous power; however, they are limited geographically to where they can be placed. They can also be a hazard or an obstacle to maritime ship traffic. This technology is still in its early stages and will take time to mature.

All these sources share the one problem of what to do when energy is not being produced. There have been many ideas put forth to solve this problem, but currently there is no clear solution. One obvious solution, is a large battery or a series of batteries linked into the power grid. While this is one of the leading ideas, the smart grid infrastructure needed to accomplish this doesn’t exist. Other ideas are large fly wheels that store excess electrical energy as kinetic energy. All of these solutions show promise, however, right now they are small scale and not suitable for industrial application.

With the global energy market in flux due to geopolitical instability, the peak in global oil production approaching, and increasing environmental concerns, the shipbuilding industry (and other US industries) needs a comprehensive energy usage plan in order to operate efficiently in an increasingly uncertain energy market. The steps outlined above will help enable shipbuilders and industry as a whole, to meet the challenges of energy generation, lessen the impact of erratic fossil fuel prices, and take a step towards energy independence from foreign sources. It will also help builders of naval ships to better control construction expenses and lower acquisition costs to the Navy.

References:
[1] Butti, K. and J. Perlin. A Golden Thread: 2500 Years of Solar Architecture
and Technology. New York: Wiley, 1981.
[2] FedEx’s Oakland Hub Goes Solar. 08 Aug. 2005. <http://www.redherring.com/Home/13107>
[3] American Wind Energy Association.
<http://www.awea.org/smallwind/>
[4] U.S. Edges Out Germany as World Wind Power Leader. Environment News Service. 26 Dec. 2008. <http://www.ens-newswire.com/ens/dec2008/2008-12-26-01.asp>
[5] Chariler, R.H. and C.W. Finkel. Ocean Energy: Tide and Tidal Power.
Berlin: Springer-Verlag, 2009.
Footnotes from Figure 1-1:
1 Does not include the fuel ethanol portion of motor gasoline-fuel ethanol
is included in “Renewable Energy.”
2 Excludes supplemental gaseous fuels.
3 Includes less than 0.1 quadrillion Btu of coal coke net imports.
4 Conventional hydroelectric power, geothermal, solar/photovoltaic, wind, and biomass.
5 Includes industrial combined-heat-and-power (CHP) and industrial electricity-only plants.
6 Includes commercial CHP and commercial electricity-only plants.
7 Electricity-only and CHP plants whose primary business is to sell electricity, or electricity and heat, to the public.
Note: Sum of components may not equal 100 percent due to independent rounding.
Sources: Energy Information Administration, Annual Energy Review 2008,
Tables 1.3, 2.1b-2.1f, 10.3, and 10.4.