Detecting Power Quality Problems in Your Home: Total Harmonic Distortion (THD)
You expect the power being delivered to your home to be safe & reliable, but that isn't always the case.
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What is THD?
Total Harmonic Distortion (THD) is a measure of how much "noise" or "distortion" is mixed into the electricity flowing in your home.
The graph illustrates clean power (green) versus power distorted by THD (red dotted line).
How does THD impact your home?
THD levels should remain below 8% according to IEEE industry standards. THD levels above 8% drive up your energy costs and cause damage in your home, including:
- reduced energy efficiency
- damaged or reduced lifespan of your appliances and devices
- compromised utility power equipment
The higher the THD in your electrical system, the higher risk. The table below describes the effects of THD as levels increase:
| <5% | Acceptable for most equipment, with minimal efficiency impact. |
| 5-8% | Minor efficiency loss and slight heating increases in transformers, motors, and generators. |
| 8-12% | Moderate efficiency loss, reduction in device and appliance lifespan, and increased overheating and circuit breaker trips. Potential for audible noise and vibrations in motors and transformers. |
| 12%+ | Significant efficiency loss and potential damage to devices and appliances, severe overheating and stress on transformers and motors, potential equipment malfunction. |
THD above the acceptable limit in your home is like dirty engine oil in your car.
The effects of high THD in electricity can be compared to having old, dirty oil in your car engine – it doesn't directly impede your car's ability to operate, but it causes inefficiency, wear, and potential long-term damage.
How do you know if your home is impacted?
Along with detecting electrical fire hazards, Ting can now measure when THD levels are above acceptable limits in homes. By integrating THD monitoring into Ting, we are helping to better understand and address grid issues on both a local and national scale.
Importantly, unlike a fire hazard detected by Ting, this notice does not require immediate action for your safety. However, elevated THD is an insidious problem that results in damages and inefficiency over time.
What actions can you take?
If you've received a notice from Ting regarding THD, you can report the problem to your utility via email so they can take the appropriate action.
Contact Your Utility Now
We've created a template to make it easy for you to email your utility.
Important: Our experience suggests that some utilities can be slow to respond. We recommend that being direct and persistent in your communication is important.
Need Assistance?
If you have any issues contacting your utility, please don't hesitate to contact our Customer Care Team for assistance.
FAQs
Why has Ting added THD as a measurement?
Your Ting sensor is designed to monitor a home's wiring for faults that could pose a fire risk. It also checks the quality of the power delivered to a home by the utility company.
As we consistently strive to improve Ting and provide additional value to our customers, we recently concluded extensive research and development regarding this often 'invisible' but important aspect of a utility provider's power quality. You can think of high THD as "dirty power", almost like driving your car without changing the oil. Dirty power is measured as THD. If Ting detects THD levels in utility power that do not meet utility industry standards, we'll guide you on addressing it with your provider.
Why should I care about THD in my home?
High levels of THD make electrical appliances and devices less efficient, wear them out faster, and even malfunction. This increases energy costs and diminishes the life of appliances, costing a homeowner more money.
How does THD affect my appliances?
If there's too much THD in a home's electricity, appliances like refrigerators, air conditioners, and even LED lights can heat up more, make strange noises, or not work as efficiently - which also means they use more energy and have a shorter life.
What can cause high THD in my home?
THD in a home electrical system can result from distortion in power delivered by the utility provider (Ting reports this measurement), devices inside the home, or both.
Distortion in local utility power can create THD that directly impacts power inside a home. If Ting generates a notice of high THD in a home, the source of the THD is the electric utility grid, as many of nearby neighbors with Ting sensors are measuring the same problem.
Can high THD increase my electricity bill?
Yes, high THD makes appliances work harder than they need to, which leads to higher energy consumption and bigger electricity bills.
Are there any outward signs that my home has a THD problem?
In many cases, high THD is hard to detect.
However, with elevated levels of THD, one might notice flickering lights, appliance buzzing noises, or devices and appliances that do not last as long as they should.
Should I be worried about THD if I'm not noticing any issues?
Yes, if a home's electrical system experiences high THD, it consumes more electricity, raising the overall cost of electricity used. It is always a good idea to be aware of THD, especially if you plan to add more electronic devices to your home or if you've experienced decreased appliance life spans.
How can Ting help if my home has a THD problem?
Ting is the first broadly available technology to empower homeowners to receive real-time THD measurements in electric utility power.
If Ting has notified you regarding high THD, you can find out how to advise your utility using the email template above.
Is there a "safe" level of THD for my home?
Generally, a THD level of less than 5% is considered safe and won't cause problems. Higher levels cause problems.
Why has my utility not already reported this 'dirty power' issue to me?
Unfortunately, utility companies do not monitor the quality of power being delivered to a home. Ting does.
Where can I get more information about THD?
THD is a complex phenomenon with applications in sound, telecommunications, and power (electricity and electrical circuits).
You can learn more by clicking the links below (these will take you to 3rd party websites):