Plant operators reap significant value compared with demand-side investments.
by Karl Fessenden, GE Energy
When it comes to energy efficiency, demand-side changes by consumers have been the focus. Consumers primarily have trimmed their daily energy diet by purchasing energy-efficient appliances, installing compact fluorescent lightbulbs or using household electricity during less expensive times.
But there’s another way power producers can achieve leaner, cleaner energy: Start at the source. Supply-side efficiency (SSE) enables existing assets to provide consistent, reliable power supply in changing market conditions and empowers plants to respond to changing demands with agility and precision. Relevant to plant managers and operators, fuel providers, utilities and energy dispatchers, SSE also:
- Extends life of existing assets,
- Improves process automation,
- Increases operational flexibility, and
- Enhances long-term availability.
SSE also breeds new thinking. It enables utilities and industrial plants with an interconnected method to assess overall performance through traditional equipment upgrades and retrofits, software and processes to monitor and diagnose efficiency so downtime decreases. Managers who view their facilities as single operating systems instead of individual components stand to gain the most from SSE.
Most Energy Used Not Converted to Power
Efficiency opportunities are so bountiful because of what today’s electrical generation leaves on the table. Some 60 percent of energy used is not converted into power during generation, according to the International Energy Agency (IEA). That’s a significant loss when spread across a power-producing fleet. Just a one-percentage point efficiency improvement in the European combined-cycle gas turbine (CCGT) fleet, for example, could save 3 billion cubic meters (bcm) in gas imports per year and reduce carbon dioxide emissions 6 million tons a year. This equates to $700 million per year in fuel savings and an equivalent reduction in electricity consumption of more than 14 million megawatt-hours (MWh), assuming an average cost of natural gas at about $7 per 1 million British thermal units.
To achieve a similar impact on the demand side, nearly 6.8 million households would need to adopt all of the most efficient, commercially available green technologies, regardless of cost. In transportation terms, this would equate to around 1.3 million drivers giving up their cars, according to GE calculations based on U.S. Energy Information Administration generation data.
Largest Aluminum Producer Reduces Fuel Costs $4 Million
For companies on a budget, SSE upgrades offer a way to incrementally integrate and upgrade current technology to more effectively manage fuel consumption and operate in smarter, cleaner and more efficient ways.
Examples of solutions already hard at work can be found throughout the world. In 2009, GE helped the Dubai Aluminum Co. Limited (DUBAL), the world’s largest aluminum producer, realize significant efficiency gains through a strategic combination of turbine rejuvenation and increases in output and efficiency. This combination enabled DUBAL to increase plant output nearly 14 percent without massive capital expenditures. By upgrading its gas turbines to run more efficiently, DUBAL reduced its fuel costs by an estimated $4 million dollars per year.
The formula for DUBAL was simple: The cost of energy makes up 30 to 40 percent of the cost of producing aluminum, according to author John Emsley in “Nature’s Building Blocks: An A-Z Guide to the Elements.” So, increasing the efficiency of its current units reduces costs, leading to growth.
Enabling Smart Life Extension, Emission Reduction
As regulations continue to shift globally, power producers also are focused on remaining compliant with local emission regulations. By making SSE improvements, plant operators can improve energy output while decreasing start-up time and emissions. For every $1 invested in SSE globally, according to the IEA, it would require $3 to accomplish the same level of CO2 reduction via demand-side efficiency efforts.
With tightening emission legislation in Spain, the S.A. Industrias Celulosa Aragonesa (SAICA) paper mill in Zaragosa, which produces corrugated cardboard boxes for global distribution, found itself at risk of losing feed-in tariffs from the Spanish government. To remain compliant with the new regulations, SAICA was part of the world’s first 6B “flange-to-flange” replacement to improve efficiency and sustainability of the plant.
Replacing the key components of SAICA’s gas turbine eliminated the mill’s need to invest in a new unit, and the comprehensive upgrade extended the plant’s life cycle and increased its operating efficiency, resulting in significant emissions reduction. With the installation of advanced design parts, SAICA experienced broader efficiency in delivering approximately 38 MW of power capability to Spain’s national power grid. The upgrades reduced the mill’s NOX output about 90 percent–from approximately 150 parts per million (ppm) to less than 15 ppm without steam injection, ensuring the plant continues to be compliant with Spanish regulations.
New Direction for Reliability, Maintenance
Plant managers must view their facilities as single systems instead of a patchwork of individual devices or operations. Advanced software solutions that enable plants to improve efficiency are affecting the ways they can operate within today’s energy landscape. These solutions also can help reduce operating costs during off-peak periods and empower plant operators with more flexibility to meet the demands of an ever-changing power market. For example, at the Great River Energy plant in Trimont, Minn., GE’s OpFlex solution helped the site eliminate 12 seasonal tunings, resulting in 1,700 hours of consecutive availability and savings on maintenance activities.
SSE also can improve reliability, often a key priority. Located in Vancouver, Wash., the River Road generating plant, a combined-cycle combustion turbine plant, is Clark Public Utilities’ only thermal generating asset and supplies some 40 percent of Clark County’s power, offsetting energy purchases. Since partnering with GE to optimize asset utilization and monitor performance of the plant in 2000, River Road consistently has maintained excellent permit compliance and has set world records–first, second and third for most consecutive days of uninterrupted plant operation.
New Levels of Collaboration Required
Energy security must be a primary consideration. Such security objectives will require new levels of collaboration and communication between the grid and power plants. Considering that the median age of North American coal plants is 44 years, according to the National Renewable Energy Laboratory, the long-term vision is to create a complete, modern, end-to-end grid infrastructure that will meet rising energy demands and comply with increasing regulations.
Energy costs are rising, and global demand for energy is expected to increase nearly 50 percent from 2009 through 2035, according to the Energy Information Administration. As demand climbs, utilities can build new plants–an expense many cannot afford–or find ways to improve the existing infrastructure through SSE solutions. Regardless, to meet this demand now, plants must ensure they are operating as efficiently and cost-effectively as possible to deliver long-term results.
Karl Fessenden is the vice president of GE Energy’s power generation services business. Based in Atlanta, he leads a team of more than 3,000 employees in more than 100 countries. Fessenden and his team assist customers in optimizing overall plant performance as industries seek cleaner, smarter, more efficient ways of operating.