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Television sets have no internal moving parts and are therefore very reliable. Although conventional television sets are built on the same CRT technology as standard computer monitors, television sets contain in-built tuners to receive and decode the television signals whereas computer monitors do not. Most standard television sets operate with AC power, although there are also television sets that operate directly on DC power.
Some types of televisions are more energy efficient than others. Of the main TV display technologies, LCD televisions usually consume the least energy for a given screen size, followed by CRT displays, flat-screen CRTs, plasma televisions, and LCD rear projection displays. Television sets with CRT picture tubes are by far the most common and least expensive units. The table below provides Winrock’s recommendations for the level of power consumption by CRT color television sets that is appropriate for off-grid use.
Recommended Power Consumption of CRT Color Television Sets for Off-Grid Projects
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Screen Size
|
Standard
|
Low Power Range (W)
|
| 13-15in (34-36cm) |
NTSC |
50-60 |
| 13-15in (34-36cm) |
PAL/SECAM |
30-40 |
| 25-27in (61-64cm) |
NTSC |
75-90 |
| 25-27in (61-64cm) |
PAL/SECAM |
60-75 |
Source: Winrock International
Turning on a TV set demands two or three times more power than is used during normal operation. If the inverter does not have enough starting capacity, it may be difficult to start up the television. It is always advisable to test the inverter to make sure it can power up the TV set reliably and consistently.
Many television sets continue to consume electricity when they appear to be turned off, particularly those that have a remote control. Even television sets that meet U.S. Energy Star requirements may continue to consume up to 3 W in standby mode. To avoid the costs of powering such ‘phantom loads,’ procedures can be put in place to ensure that the sets are physically unplugged, or otherwise disconnected from the power supply, when not in use. This takes on increased importance in PV or small wind power systems because of the relatively limited amount of power produced. One option is to use an inverter with a switch that cuts the power to the whole load. Also, some television sets have a “hard off” switch on the main body of the unit that disconnects the device from the external power supply, even though the TV power cord remains plugged in to the outlet.
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