The need for efficient power delivery has become a political rallying cry for established and emerging economies alike. This article addresses the types of capacitors that make power factor correction a reality.
Introduction to Power Factor Correction Capacitors
Power factor correction capacitor markets were worth an estimated $1 billion USD worldwide in 2020. We expect the power factor correction segment of the global market, especially for power transmission and distribution, to grow steadily over the next ten years due to the increased global demand for power efficiency in the electrical distribution system, as well as heavier-load electrical motors and drives.
Governments of both the established and emerging economies are beginning to draw direct correlations between healthy economies and efficient power generation, transmission and distribution. This trend will also fuel demand for AC polypropylene-type power factor correction capacitors.
What is Power Factor and Why Does It Need Correcting?
In an electric power system, a load with a low power factor draws more current than a load with a high power factor for the same amount of useful power transferred. The higher currents increase the energy lost in the distribution system and must be corrected.
The preferred method of correcting power factor is through the placement of capacitors throughout the system – at the point of transmission or distribution, or where the load occurs (i.e. mounted directly on an electric motor, or on the printed circuit board of a lighting ballast).
What Types of Capacitors are Employed for Power Factor Correction?
Almost all power factor correction capacitors are manufactured from polypropylene plastic dielectric materials. The polypropylene dielectric may be interleaved with specialty paper and/or specialty metals, such as aluminum or copper foils. Alternatively, the polypropylene may be metallized or unmetallized depending upon the capacitor application.
Polypropylene capacitors used for power factor correction can further be broken down into their various market segments as follows:
- Power Transmission and Distribution PFC Capacitors
- Industrial PFC Capacitors
- Motor Run PFC Capacitors
- Lighting Ballast PFC Capacitors
Power Transmission & Distribution Class PFC Capacitor Markets: FY 2020
Power factor correction capacitors are used in modern electrical grids at the point of transmission and at the point of distribution. Power factor correction capacitors are also used in large volumes at interconnects where renewable energy sources, such as wind or solar, are connected to an existing grid.
Capacitors Used in Series and Parallel
Distribution-class power factor correction capacitors are generally pole-mounted, outside plant components that are rated from 3 to 38 kilovolts, while power-transmission-class capacitors are employed at power transmission stations and employed in both series and parallel configurations, which employ as many individual capacitors in rack-mounted banks as required to achieve voltages up to and including 800 kilovolts.
Capacitance values for polypropylene type capacitors are limited, and therefore the microfarads required for the system must be addressed through the adoption of multiple capacitors in parallel and series.
Recent Market Activity for PFC Capacitors
Customers for power-transmission and distribution-class capacitors are public, private and government-owned power utility companies that supply power for residences and businesses globally.
Market activity in power factor correction for large substations has been noted globally throughout 2019 and 2020, especially in countries dedicated to expanding their offshore wind programs (Germany and China) and in emerging economies.
Market demand from public utilities is dependent on a nation’s need for clean and continuous power and energy at an affordable price. From 2000 to 2020, Northern Europe and China remained the dominant areas of new growth for vendors of power generation, transmission and distribution equipment – including PFC type capacitors.
PFC Capacitor Purchases are Technology-Driven
Manufacturers of PFC Capacitors for power transmission and distribution applications are primarily divisions of much larger power equipment manufacturers, who supply their capacitors as a line item for larger turnkey operations.
Smaller vendors of power factor correction capacitors for high-voltage transmission and distribution applications are beginning to grow in this segment due to their advanced “dry-type” technology, which offers more volumetrically efficient designs when compared to capacitors filled with dielectric fluid.
This movement to smaller, lighter capacitors has been the latest technical trend in PFC capacitors and signifies a shift in consumption, with major turnkey suppliers more frequently sourcing the merchant market for PFC “dry-type” capacitors because their captive capacitor operations have not progressed at a rate equaling that of vendors in the merchant market.
Renewable Energy Interconnects Drive Demand For “Dry-Type” PFC Capacitors
Both high-voltage AC and high-voltage DC transmission systems employ large can capacitors for power factor correction. HVDC systems are growing in popularity, especially for offshore wind generation and interconnects with existing grids to correct the power factor. The movement to HVDC systems with static converters will continue to accelerate demand for polypropylene film capacitors between 2020 to 2030 in an effort support the efficient transfer of energy and the connection of renewable sources of energy to the existing power grid.
Motor Run PFC Capacitor Markets: FY 2020
Motor run capacitors are consumed in the global AC electric motor and drive markets worldwide. Split capacitor-type motors, for example, are used in air conditioner compressor motors, refrigerator compressor motors and ceiling fans. Between 2010 and 2020, the market for motor-run capacitors saw only minor activity, spurred on by the churn in motor markets due to the development of more efficient and cost-effective motors, and by the technical trend of combining motor-run capacitors with motor start capacitors in the same capacitor module.
The vendor base for motor-run capacitors is fragmented (there are many vendors around the world, a testament to the ease of market entry). The reader should appreciate that this is an extremely fragmented market; I have identified 19 motor-run capacitor vendors worldwide.
Industrial Power Factor Correction Capacitor Markets: FY 2011
The low-voltage industrial power factor correction market is considered an extension of the power transmission and distribution power factor correction capacitor market worldwide: many of the vendors are the same.
Capacitors consumed in low-voltage power factor correction applications are generally rack or wall mounted systems that contain large can polypropylene capacitors in series. These industrial-grade power factor correction capacitor banks are mounted at factory locations, either at the service entrance or at the load itself, to correct the power factor and keep energy costs low.
The market driver to this segment of the industry is that some electric utilities offer incentives to manufacturers who demonstrate more efficient power consumption.
Lighting Ballast (PFC) Capacitor Markets: FY 2020
Power factor correction capacitors have been historically consumed in two separate markets in the lighting ballast industry, the magnetic ballast business and the High Intensity Discharge (HID) lighting business.
Power factor correction capacitors consumed in magnetic ballasts are a challenging business for vendors because magnetic ballasts are inferior in their performance to electronic ballasts, which consume no power film capacitors for power factor correction (although they do consume plenty of high-value DC film capacitors, including interference suppression, AC and pulse, and SMD film chip capacitors for bypass, decoupling and filtering).
In the United States and Europe, government regulations mandate replacement of magnetic ballasts with more efficient LED lighting ballasts; this has had a negative impact on the supply of polypropylene film capacitors to the lighting industry in 2020.
Summary and Conclusions
We estimate that overall demand for power factor correction capacitors will increase over the next decade, as world governments in established and emerging economies continue to make the correlation between robust economies and efficient power infrastructures.
In some key instances, such as in power transmission and distribution, motor run and industrial power factor correction, demand for power factor correction capacitors will grow in accordance with the mega-trend toward delivering power more efficiently.
The PFC market also offers new opportunities for traditional component manufacturers who have developed “dry-type” alternatives to “wet” capacitors, with dry-type polypropylene film capacitors offering as much as a 30 percent reduction in size. This allows for smaller static converters and smaller power transmission and distribution footprints worldwide.
Polypropylene type capacitors will continue to be used in power factor correction applications over the next ten years because of the low cost per microfarad. PP film is inexpensive because of its abundance; it is the primary plastic used in soda bottles. Polypropylene type capacitors also have the ability to operate up to 800 kilovolts when packaged in series and parallel.
Growth markets will be for “dry-type” constructions consumed in power transmission and distribution grids, and for low voltage power factor correction at the load.
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