My family's electricity consumption is about 150 kWh/week. But now I'm going to calculate how much all of our entertainment electronics consumes electricity. So I started in my room.

Ok, there are my alarm-clock radio, our old TV and my laptop. All of those work with electricity from grid (line current).

My Sony alarm-clock radio, which I got from Santa Claus, is always on stand by, but it consumes only a little electricity. The power is 5W. I got the power from diagram P=UI. W=Pt (J=Ws), with this I can get the work. I use my radio about hour in a week. So it's 0,005kW x 1 hour = 0,005kWh (kilowatthour). So with this diagram I can solve my trouble and all of the calculations. Here electricity costs about 0,1€ (Euro) per kWh.

My TV is about 6 years old and it's about 20 inches television tube. The brand is Grundig (a strange  for me). Its power is 55W. I use it 6 hour in a week. So 0,055kWx6h = 0.33kWh/week.

My portable computer is 3 months old. It's Asus G1S and there is 15,4 inches LCD (Liquid Crystal Display). The power is 90W. I use it about 3 hours per day so it makes about 20hours per week. But it's on stand by about 4 hours of that 20 hours. The power is about 8W when it's stand by. So 0,09kW x 16h = 1,44 kWh/week. And 0,008kW x 4h = 0,032kWh. 1,44kWh + 0,032kWh = about 1,47kWh.

In our hall there are our old DVD-player and our stereo. The Sony's DVD-player is about 4 years old, and it's just there. Nobody uses it. The power is 13W. We use it on average maybe 5 minutes per week. So it's something like 0,001kWh/week.

Stereos are like 10 years old. They are Yamaha/Onkyo. They are quite good, even though they are so old. The power is 20W and we use them maybe hour/week. So 0,002kW x 1h = 0,002kWh.
So alltogether they are 0,003kWh/week.

In my brother's room there are TV, digibox, loudspeaker system, computer and LCD. So there's a lot of electricity consuming.

His TV is Philips 28 inches television tube, which is about 4 years old. Power is 105 Watts. He uses it maybe 9 hours/week. So it's 0,105kW x 9h = 0,945kWh. When he doesn't watch it it's switched off. It's not on stand by.

He uses with that a Humax digibox, which has power of 10W. It isn't on stand by. He uses it as much as his television, so it's 9hours. 0,001kW x 9h = 0,009kWh.

Then there is Dell's 5.1 loudspeaker system, which he bought with his computer. His computer is 3 years old. The speaker system is on the computer. System's power is 95W.  He uses it maybe 5 hours in a week. So it makes 0,475kWh.

He has Dell Dimension 5100 computer with a Dell 19” LCD. So like i said they are 3 years old. The power together is 220W. My brother uses them almost 18 hours in a week. But they are couple of hours on stand by. Stand by is 10 watts. So 0,22kWh x 15h = 3,3 kWh. 0,01W x 3h = 0,03kWh. Then they are 3,33kWh.

In downstairs there are our new TV, new digibox, quite new DVD-loudspeakersystem, my mom's new job-notebook and Nokia's mobilephone charger.

Ok, lets start on TV. It's almost half a year old Mirai 42 inches Full HD (High Definition) LCD-TV.  
Mirai's power is quite creepy, 280 Watts. It's always on stand by so that also consumes energy. On stand by power is 1 W. We use it maybe 4 hours per day. So 28 hours in a week. And on stand by it's
24h x 7h – 28h = 140 h. So 0,28kWh x 28h + 140h x 0,001kWh = 7,98 kWh.

Our Digibox is also always on stand by. It is Procaster and it has 200gt recording space. We bought it last summer. Power is 30 W. It's about 0,9 kWh.

Then we have a DVD-loudspeakersystem. It's 2 years old JVC and the power is 90 W. We use it when we watch movies, so like 6 hours in a week. Then it makes 0,54 kWh.

My mom got a new job-laptop this year so I put it here. The model is Lenovo T61 and the power is 75 Watts. She uses it maybe 4 hours in a week. It makes 0,3 kWh/week.

We have 4 mobilephones in my family. So we have to sometimes use mobilephone charger. It's Nokias charger and we use it 10 hours in a week. Power is about 5 Watts. The work is 0,05kWh.

Now I can calculate how much we use entertainment electronics. 0,005kWh + 0,33kWh + 1,47kWh + 0,001kWh + 0,003kWh + 0,945kWh + 0,009kWh + 0,475kWh + 3,33kWh + 7,98kWh + 0,9kWh + 0,54kWh + 0,3kWh + 0,05kWh = 16,338kWh/week

So our electricity consumption was 150kWh. So entertainment electronics consumes 15kWh. So it's 10 % of the whole consumption. It looks like that heating is quite important thing in electricity consuming.

And the entertainment costs in a week 150kWh x 0,1e/kWh = 15 euros.