What is a kilowatt hour? Understanding home energy use

Utilities bill for electricity in kilowatt hours (kWh), but what does that mean exactly? And what is the difference between a kilowatt and a kilowatt hour? Knowing the difference helps you understand the impact of your home energy use on your electric bill. You can also compare your use to the energy generated with your Enphase system to appreciate the energy savings on your utility bill.

[garrettlees]

So, if you have a 1 watt bulb and you turn it off, do you kill a watt?

[OliveMule]

Enphase explains all of these concepts better than the school I paid for.
I believe the schooling is trying to be confusing on purpose because enphase makes it click real easily for me. Thanks enphase, we will continue to use your products. We love you're micro inverters

[andargachewdessie]

Thank you for such a clear and easy to understand video. God bless!

[joeiken]

Why would someone dislike a video like this?

[himaloyshadhin]

After watching lots of video, i clearly understand from this one.

[.explorer]

What is the calculation you did to arrive at 260 kWh/year?

[honghaphanthi]

The video sound is pretty good, beyond my imagination

[mgabrielle]

What many people don't realise, that if you fill an electric kettle with more water than you need, it can really add up to your bill, using an electric kettle rated at 2750watts of power consumed at a mains voltage of 230V AC, if the mains voltage goes up to 240V AC, the kettle becomes rated as 3000watts or at 220V AC it becomes rated lower to like 2500 watts approx. But higher wattage simply means it will take less time to boil a same amount of water than a kettle running at lower wattage, just as cars with bigger engine can go faster and reach quicker.
But this is what is shocking is that I boiled exactly 2 cups of cold tap water (20 deg C) and brought it to boil in 1 Min and 25 seconds using 2750 watts of power,

2 cups of water is the minimum amount of water you need to fill otherwise you risk overheating the kettle and reduce its life, so the amount of actual energy can be worked out easily, you take 2750 watts and divide by number of seconds in 1 hour that is 3600, and then multiply the result by number of seconds it took to boil that water from 20C to 100C, which in my example was about 85 seconds, so this equates to roughly 65 watt hour of energy, what this means which is shocking is that this amount of energy used just in 1 Min and 25 seconds is same a s a 5 watt LED light bulb that can give decent amount of light in a small room running up for 13 Hours! So when energy bills have gone so high, cost of food has rocketed, then decide weather you really want to have a cup of tea.

So from this example, making just 2 cups of tea costs as much as running a 5 watt LED bulb for 13 hours or a 10watt LED bulb for 6.5 hours, by switching off all my appliances from standby to completely off, most modern TVs and Laptops when on standby draws virtually no power, but older appliances may do so, Sky Q receiver box was the biggest culprit as it drew more than 15 watts (typically around 18watts ) when in standby, I had two Sky Receivers and so between them two they were consuming nearly 25watts 24hors a day and night, that is almost a kilo watt hour (840watt hour) add my laptop active speakers with base boost, it drew 10watts all the time even when it was not making any sound, my laser printer always plugged in and in standby draws another 10watts of energy 24hors a day and night, my gas hob and oven drew another 5 watts all the time which i have now switched off completely and use external igniter, replaced all light bulbs from energy saving ones to LED bulbs, got rid of 4 tube lights 56 watts each and replaced them with 28Watt LED Tube lights, and even then I only switch on which ones I need, I have slowly adjusted to live reasonably comfortably in dimmest lights, you get used to low lights if you have to, as no way I am paying huge amounts of my savings down a drain, so now I have brought my electric consumption from around 12 to 15 kilo watt hours right down to about 5 Kilo watt hour, I am so pleased and am actually enjoying bringing it even further down.

As for drinking tea, I love tea so i cannot go without, but I now only boil 2 cups maximum whereas before being aware I used to boil a half to 3/4 full kettle.
You can all do it if you really want, smart meters help as it makes you become aware, but better than those smart meters is the plug in energy meter sold on eBay fro under £15 which can check individual item how much energy is being drawn by a particular item, by energy bills shot from £126 per month to well over £362 per month, so this is why I took this drastic approach and cut out all crap, use my energy as though i am living black out and dim lights are my emergency back up lights. So now my average power consumption is around 200 to 250 watts each hour, I am planning to invest in a solar power that would further reduce my energy bills. I will not engage expensive solar power companies but hook up my own panels even if I have to hire a scaffolding, its cheaper to do it yourself, just hire an electrician competent in making your final connection and commission. Buy your own solar panels.

[brandonbarrientos]

Sorry for the dumb question but so if i have a 1000 watt light and i leave it on for10 hours how many kilo watt hours would ive wastes.. 10??

[Dani-itsy]

This is the longest explanation of what a KWh is.. But at least my 5 year old understands it now..

[showmoon]

made easy to understand ! good use of analogies

[lehuong]

how did you do it can you share with me, thank you

[cthncthn]

so...'hours' in kWh/Wh doesn't really mean 'hours' per se? Does It just means the appliance Wattage multiplied/divided by any length of time? eg a 3kW appliance running for 30 minutes uses 1.5kWh hours...obviously it didn't run for an hour but it is still represented as the watts multiplied by hours. If this is true then I should never interpret an appliance using 10kWh to mean it used 10kW in one hour- it just means it used 10kW in some unknown amount of time unless some states the amount of time. Am I finally understanding?

[rickywhite]

Our electric bill is over $500 a month for the last two months. That's a 200% mark up!!!!

[Godisnotjesus]

Nice video, thanks. Can you help me calculate how much electricity my water pump consumes per hour. I use a Wizz mini motor made in Italy.

[trackpackgt]

Yeah I bet the power companies hate these new low watt LED bulbs LOL they're in every socket of my house

[thomasjacques]

My AC system typically cycles between 6 and 7 minutes per hour even on the hottest day (we have a new high-efficiency home). How would I determine how many kWh my AC system uses overnight if operating on a battery backup? During an hour how much power would my house be consuming from my batteries given the light load the house uses at night.

[funentertainment]

Nice video I always turn off extra light and light up candle 🕯 😍😍

[positunestudio]

In 2:50 you mentioned (ignoring the grammar) “kWh is a measure of energy which is power over time” or in other words “energy = power / time” which is a bit confusing.

Energy is measured in Joules. Power (Watt) is energy (Joule) over time (second) or 1 Watt = 1 Joule per 1 second. Hence by definition, kWh is 1000 x (Joules / sec) x hour. If we convert and strike off the time units, then you are right, kWh is effectively just Joules (energy).

But a better statement would be “kWh is a measure of total energy in a period of time”.

[ticktockbam]

What about the amount of Watts that a specific electric line (your house, for example) can provide before making the safety switches go off? Do different houses/electric lines provide different amount of limits of electricity you can use before making the power go off with the safety switch for safety reasons? I'm asking because I would want more power limit in order to connect more appliances to be able to power them at the same time without the safety going off.