Plant optimization and energy efficiency

2014-03-31 - ABB plant optimization and energy efficiency solutions enable power producers to maximize plant performance and achieve significant benefits and savings in all types of market –dynamic response, base load and renewables integration.

In mature markets the days of thermal power plants operating constantly at base load are over. Often these plants now have to operate as back-up to wind farms and solar power plants, running below their designed capacity and ramping up or shutting down several times over a 24-hour cycle. For power generators in these markets, the ability to respond quickly and costeffectively to rapidly changing load requirements is crucial.

In developing parts of the world, where there is often a shortage of electric power, thermal power plants continue to operate around the clock at base load. Here there is scope for huge savings to be made by optimizing plant performance or improving the plant’s energy efficiency. The objective is to increase plant electrical output with a given and limited amount of resources.

In many countries – developed and developing - there is a need to participate in intra-day and day-ahead energy trading efficiently in order to maximize returns. This can be achieved by optimizing unit production in a multiunit conventional power plant, or by integrating small renewable energy installations into one large virtual power plant in distributed generation.

ABB has a proven and comprehensive range of plant optimization and energy efficiency solutions that enable power generators to thrive in these diverse market requirements.

Throttle-free frequency control

MODAN and MODAKOND is a unit control solution that delivers the fast load ramps and frequency control required to meet the dynamic response schedules of load dispatchers in mature markets. It does this by coordinating the boiler, turbine and energy reserves by means of model-based set-point control and model-based feed forward control. This eliminates the need to throttle the turbine control valves. Whereas throttling usually achieves the desired results but lowers plant efficiency, MODAN and MODAKOND improve plant efficiency by 0.3 to 0.4 percent.

The two products can be installed as an integrated control solution in units running on ABB control systems or as an optimization solution to upgrade power plants running on non-ABB control systems. Installations at more than 80 power plants show that a typical 700 MW unit operating at an average load of 88% can reduce energy consumption on throttling by around 10,150 MWh a year. The annual cost savings for such a reduction are around $270,000.

Optimizing start-ups and shutdowns

Because of the increasing number of start-ups and shutdowns that thermal power plants have to perform – often several times a day - power generators need to know how long it will take from firing up to synchronization in order to meet the required load scheduling. They also need to keep the cost of these potentially budget-busting boiler start-ups as low as possible.

One example of many at which OPTIMAX® BoilerMax has achieved considerable savings is at the 840 MW Ingolstadt oil-fired power plant in Germany. The plant is operated by E.ON, one of Europe’s leading energy companies. OPTIMAX BoilerMax has reduced fuel consumption and greenhouse gas emissions at the plant by 20 percent. Ingolstadt is one of several E.ON plants in Germany that now benefit from lower fuel costs and a reduced carbon footprint thanks to BoilerMax.

OPTIMAX BoilerMax has reduced fuel consumption at boiler start-ups by up to 20% at an E.ON oil-fired power plant in Germany.

Actual vs. expected plant performance

ABB’s OPTIMAX PlantPerformance is an online plant performance monitoring system that continuously compares actual plant performance against expected performance. It does this by monitoring plant components and variables - such as turbines, generators, heat rate and efficiency - and comparing the actual values with set points. The performance data is displayed on an automatic, periodic or on-demand basis. Controllable losses show the cost impact of operating the plant beyond its design point, and what-if calculations reveal the cost benefit of improving those controllable losses.

OPTIMAX PlantPerformance provides early detection of wear and tear and improves plant availability and efficiency. It also provides real-time records of deviations from normal operating parameters, which help to establish, diagnose and predict performance trends. This type of information enables management to make more precise and cost-effective decisions on investment or maintenance activities. For instance, a decision to defer an investment thanks to precise information on component performance frees up capital for more pressing purposes.

Improving plant energy efficiency

For plants that operate at base load, the quickest and least expensive way to improve output and reduce operating costs is through energy efficiency. It not only generates more power and higher revenues, it reduces fuel consumption and greenhouse gas emissions.

ABB has a comprehensive portfolio of energy efficiency solutions that meets the strategic and operational requirements of all types of thermal power generation. They include:

• Plant energy efficiency assessments in which ABB identifies the efficiency improvements and savings that can be made in the plant’s main energy systems
• Plant and process optimization systems that improve the efficiency and lower the energy consumption of plant equipment and power plant units
• Electrical balance of plant upgrades that improve plant energy efficiency by modernizing selected areas of the plant electrical system and installing energy-saving technologies such as variable speed drives and actuators.

One of many examples where ABB has identified huge annual energy savings is at a large power and desalination complex in the Middle East. ABB conducted an energy efficiency assessment in 2011 and noted 32 energy-saving opportunities in various site systems. These were estimated to be worth up to 400,000 MWh a year and $11 million annually. One opportunity alone offered potential fuel savings of $1 million a year.

ABB identified 32 energy-saving opportunities worth up to 400,000 MWh/yr or $11 million annually for a power and desalination complex in the Middle East.

Multi-unit integration and optimization

The escalation in renewable energy generation has significantly increased the number of power production units that deliver electricity to the grid. Small renewable energy producers, as well as thermal power plants with multiple units, have to participate in intraday trading and maximize their revenues. OPTIMAX PowerFit makes this possible. It enables:

• Multi-unit power plants to optimize plant production and respond rapidly and efficiently to changes in load dispatch requirements
• Combined heat and power (CHP) plants to optimize and balance heat and power production
• Municipal energy storage facilities such as CHP plants and pumped storage plants to optimize production and participate in intraday energy trading
• Multiple small renewable energy production units to pool and optimize output and form a virtual power plant that can participate in the energy trading market.

OPTIMAX PowerFit has a proven track record in all four applications. One example is a solution for a German-based virtual power plant operator that trades on the national energy spot market.

PowerFit enables the company to pool and optimize around 600 MW of energy generated by some 300 wind farms, photovoltaic power plants and biogas plants located all over Germany. The power is traded on an intra-day and next-day basis, thereby providing many small-scale energy providers with the same market advantages as large conventional power plants.

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