# What are Watt, Kilowatt and a unit of electricity

When we get our electricity bills, it shows that we have used a certain number of units for the given period. When we go to buy appliances, most of them have watts mentioned on them. If you find it difficult to understand the relation between the two, then you are not alone. Electricity bill and its components are confusing to many and with this article we will try to explain what are watt, kilowatt and a unit of electricity.

### Power and Energy/Electricity

Power and Energy/Electricity are two words that are used so much for each other that many feel that they mean the same. Interestingly both of them have a very different meaning. Power is the rate at which electricity is used and energy/electricity is the actual consumption. To give an analogy, power is similar to speed but electricity/energy is the actual distance travelled.

So Power x Time = Electricity (or energy)

Just like Speed x Time = Distance Travelled.

### Power and its units

Power is always represented in watt (W) or kilowatt (kW). A thousand (1000) watts make one kilowatt. So if any appliance is rated as 1.2 kW then it means that it consumes electricity at a rate of 1200 W. Now as we discussed earlier that power is the rate at which electricity is consumed and not the actual electricity consumed, Watt or Kilowatt just represent the rate at which electricity is consumed per hour. Which means that when you buy a 100 W bulb, it does not consume 100 units of electricity but consumes at a rate of 100 W.

### Energy/Electricity and its units

A unit (as mentioned on the electricity bills) is represented in kWH or Kilowatt Hour. This is the actual electricity or energy used. If you use 1000 Watts or 1 Kilowatt of power for 1 hour then you consume 1 unit or 1 Kilowatt-Hour (kWH) of electricity. So the reading on the electricity meter represents the actual electricity used. Just like the odometer on your vehicle that shows the actual distance travelled by the vehicle, electricity meter shows the amount of electricity that is used. So a 100-Watt bulb if kept on for 10 hours will consume:

100 x 10 = 1000 Watt-Hour = 1 Kilowatt-Hour (kWH) = 1 units (on your meter).

### Estimating units consumed by any appliance

Now with most of the concepts explained we would like to make it easy for you to calculate how much units does any appliance consume. Most appliances have wattage written on them (either on their container box or somewhere on the appliance). Once you have the wattage, next you need to figure out how many hours a day do you use it. After that you can use the formula below:

Daily Units = (Wattage x Usage hours per day) ÷ 1000

Monthly Units = Units x 30 (or 28,29,31 based on month)

Please note that this formula may not work always. For appliances like Air Conditioner, Water Heater, Cloth Iron (any heating or cooling device) and pumps, this will not work.

### Source of Information:

http://www.energysavers.gov/your_home/appliances/index.cfm/mytopic=10040

http://en.wikipedia.org/wiki/Watt#Confusion_of_watts.2C_watt-hours.2C_and_watts_per_hour

## Leave a Reply

85 Comments on "What are Watt, Kilowatt and a unit of electricity"

## If you have any question or comment, please leave a message here. We try to reply to questions in the sequence they come in. We work from Monday-Friday 10AM-7PM. If we know the answer we try to reply to the question within 3 days.

Contact : Solar grid solutions for

Home/ Institutes/ hospitals/ malls/ industrial areas 2 KW to 10 MW. We provide services across India at very nominal rate which are competitive in market.

For any query, Call : 9312700996

visit us at : http://www.solarbird.in

Sir residential area m 2 kw meter kliye e unit charge kya h gzb shastrinagar m meri unit 300 to 500 k between rehti h

Gzb UP mein pehle 150 units ke liye Rs 4 hai, agle 150 units ke liye Rs 4.5 hai aur fir agle 200 units ke liye Rs 5 hai aur usse zyada sab ka Rs 5.5 hai. To agar aapke 500 units ek mahine ke aaye hain to aapka bill 150×4 + 150×4.5 + 200×5 = 2275 ka energy charge aayega. Uske upar 2 kW ka fixed charge aur electricity duty aur taxes aayenge.

sir, there is server consuming 2540 watt , runs round the clock. How many units it will consume in a month.

Hi,

2540 watts means 2.54 units in an hour. You can multiply it by 24×30 to get monthly consumption.

Dear Sir/Madam

I am using a old desert cooler, it’s Motor (fan) was rebind from local mechanic, it consume 0.7 unit (3688.5 – 3687.8) in the 3 hours (morning) , I have digital meter (Electricity Board Chandigarh), What actual Wattage consumption is for this motor? (Pl calculate for 10 hr too)

Thanking you

0.7 units in 3 hours means 0.7 kWH in 3 hours or 700 Watt-hour in 3 hours. So its wattage would be 700/3 = 233 Watts. And if it consumed 0.7 units in 3 hours then it would consume (0.7/3)*10 = 2.33 units.

I want to know that 1.2 ton ac with 5star rating.. How many unit it will takes in 8 hours..

Hi Limras,

How many units an AC consumes per hour depends on lot of factors, like the size of the room, os the Ac oversized or undersized, placement of AC, and brand etc.. So we cannot accurately calculate how much an AC will consume. But a BEE 5star 1.2 ton AC should consume about 0.9-1 units/hour. So for 8 hours it should consume about 7.2-8 units.

I to know one thing. power plants produce some power. assuming that a plant produce 1MW power. that means is it for a day or a month or an year. from 1MW how many units will we get. I heard that we can produce 1MW solar power from 1 meter square place. Is it true. hear we have heat about 38 – 41 degrees centigrade.

Hi Shanawaz,

1 MW is 1000 KW which is the rate at which electricity is produced by power plant. It is not the actual electricity units produced. If 1 MW plant runs continuously for 1 hour it will produce 1 MWH = 1000 KWH = 1000 units of electricity. You can read more about a solar power plant vs regular power plant on this link: https://www.bijlibachao.com/energy-efficiency-and-other-articles/comparison-of-the-output-capacity-of-a-coal-power-plant-vs-solar-power-plant.html

HI SIR I HAVE DOUBT FROM BE UNITS..I WANT WHICH READING DAILY I TAKE AND HOW TO CONVERT TO UNITS

Hi Vivek,

I could not understand your question.

I want to know that 1.5 ton ac with 3star rating

how many units it will consume in one hour

Hi Pradeep,

The electricity consumed by an AC depends on lot of factors. So we cannot accurately calculate how much an AC consume in an hour. Bua A 1.5 ton 3 star AC should consume approximately about 1.4 units/hours.

if one water pump- 1 inches pipes, of 1 Hp runs 5 hours a day then how much units it will consume in a day or in a month………

Hi Raj,

1 HP is 750 watts. And 750 watts for 5 hours is 750×5=3750 Watt hour or 3.75 kWH or 3.75 units of electricity in a day. Assuming 30 days in a month it is 112.5 units a month. This is a rough calculation as the consumption will also depend on load (full load, partial load, etc).

thanks for answer….its good to manage electricity bill for me ……

Contact for Solar grid solutions for Institutes, hospitals, malls, industrial areas and large scale plant 200 kva to 10 MW. Our manufacturers have very vaast experience in this field. We provide services across India at very nominal rate which are competitive in market.

For any query, please feel free to contact us at +91-9312700996

Hello sir I want to put one me solar plant in Punjab ,mukerian tehsil I have 4 acre land .how much it cost and how much land I need for 1 mw unit

You need about 4.5 to 5 acres of land to setup 1 MW plant. You can refer to this link to get more information: http://efficientcarbon.com/services/energy/renewable-energy-advisory/frequently-asked-questions

Dear Sir Thanking you …

if you have to plan setup the 1 MW pv solar power plant Land requirement is Minimum 5 acres land (non Agriculture conversion land )