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 Download an 'Overview of Power Factor Correction' |
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| Overview |
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| Most commercial and industrial operations use electric motors and additional plant such as florescent lighting, ventilation, refrigeration, air conditioning, welding equipment and arc furnaces, all of which are inductive loads. |
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| Typically, these inductive loads operate at around 80% efficiency and at even lower efficiencies when they are not functioning at full load. An inductive load operating at 80% efficiency will waste 20% of the current it draws from the grid. |
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| Power Factor Correction reduces the amount of power drawn from the grid by inductive loads, thus reducing the amount of power wasted by the loads on a circuit. |
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Power Factor Correction has been in use for decades by utilities and heavy industrial operations, but the recent rise in energy costs has rendered the technology cost effective for lower energy users such as commercial installations and light industrial units. |
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| Benefits of power factor correction | |
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| The benefits of PFC include: | |
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| Financial | |
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| • | Reduces electricity consumption and fuel bills |
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| • | Reduces or eliminates utility penalties for low power factor (reactive power charges) |
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| • | Extends lifetime of machinery thus reducing equipment replacement costs |
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| Emissions reduction | |
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| • | Reduces carbon emissions (as power companies need to produce less electricity in fossil fuel fired power stations) |
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| Electrical System and Power Quality | |
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| • | Reduces power losses in cables and transformers |
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| • | Increases power transmission capacity in cables |
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| • | Increases available transformer capacity |
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| • | Improves voltage stabilisation in long cable runs |
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| Motors and Appliances | |
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| • | Reduces wear and tear on motors |
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| • | Provides a degree of surge protection |
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| Electricity savings | |
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Typically, a commercial installation that installs power factor correction will reduce the electricity used by each inductive load that has it spower factor corrected by between 5% and 25%. |
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| Return on investment | |
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| Return on investment depends upon the savings achieved and the costs of installation, but will vary between 6 months and 5 years, with 2- 3 years being typical. The design life of the equipment is 10-20 years. | |
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| Prices vary greatly as many installations require bespoke sizing. As a guide, here is an estimate for an installation at a college site: | |
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| Power Factor Correction: Example ROI | |
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| Annual electricity bill: | £51,350 |
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| Price paid per kWh: | £0.07 |
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| PFC Installation cost: | £15,000 |
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| PFC % achieved: | 15% |
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| Annual kWh saved: | 110,036 |
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| Est. financial saving: | £7,703 per year |
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| Estimated emissions reduction: | 59 tonnes CO2 per year |
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| Payback time: | 23 months |
