I've just been watching Britain from Above, where they were talking about the infrastructure of the UK... part of which involved talking about the issues of the tea drinking nation that is Britain making a cuppa at the end of Eastenders (other soaps are available). This got me thinking...
But first an aside....
Being a power station geek, I have of course visited Dinorwig and Cruachan, which are two power stations which exist in order to feed the grid in times of need (and also eat from the grid when the grid isn't hungry). They are hydro-electric and the idea is that they can be switched on to provide electricity in seconds when it's needed and can also use up electricity by working in reverse, pushing the water back up to the top.
Now imagine the grid is like a car... you're driving along the flat road and the engine is doing fine, then Eastenders ends and "Wham!" the roads become into a big steep hill to climb. As you start going up the hill if you don't increase the accelerator the car engine will slow down (as will the car). The same happens with the grid - you might have heard the frequency of the mains in the UK is 50 hertz, that means that the voltage goes up and down 50 times a second (which is related to the speed of the shaft in the generators at the power stations). Well... when there's load on the grid all the generators slow down (like the car and the hill). This is bad and when this starts to happen they know to turn on the extra power stations.
There's the opposite too... imagine the car again.... everyone's kettle has boiled and you're at the top of the hill. The only way left is down, and your engine speeds up again... but now it's going faster than it should!
Same happens in grid land, the line frequency starts to go above 50 Hz - also bad.
So.... back to my thinking.... I decided that I wanted to make a gadget to plug in to the power supply that would let me graph the line frequency, then I could see for myself the effect of Eastenders ending - and then them in gridland fixing it.... and then it speeding up... and gridland fixing it again. "Great" you're thinking. You see I'm a geek, this would be cool for me to see.
This then got me thinking... "I bet someone else has done this... and put it on the web in realtime.... maybe even the National Grid themselves," I thought... so I did some Googling. I found this... dynamicDemand. It's unfortunately broken (at the time of writing) and seems to show the frequency as 50.103 Hz all the time. Not to worry. By now my thinking was pretty much about what the rest of that site is about. Because you can measure the line frequency in realtime from any plug socket in the land, with a little bit of gadetry you could base your usage of electricity upon the line frequency - in order to be beneficial to the grid and all friendly like.
The site itself seems to be based around doing this stuff for industrial freezers and air con and the like - which aren't really going to miss being turned off for 2 minutes every time Eastenders ends - not that it'd have to know it was Eastenders, all it would have to do is realise that the line frequency wasn't 50 Hz.
There's a company in the states who make these boxes and actually make money from it, by selling the energy that the company isn't using (by having their stuff turned off) back to the grid.
I thought it'd be nice if the general public could chip in too - in an altruistic manner. Initially, I thought of something like an inline plug thing (like a timer clock) that checks the line voltage and turns itself off when energy is needed elsewhere. That involved thinking of appliances (which are relatively high powered) in the house which can be plugged in and don't mind being turned off randomly. The only thing I could think of was the kettle (also possibly heaters). This of course is a problem. It's the ruddy kettle that's causing the dip in frequency as it is... and I'm pretty sure that if you went to boil your kettle and it didn't work because people without "polite kettles" had got there first - you'd be making a brew 5 minutes later... and then all the "polite" kettles would be putting undue load on the network. Also as a consumer you'd get annoyed 'cause kettles are usually used when you want a drink now, not when the grid is up to it.
I'm sure that someone will remember (Bill, if you still read this?) that for my GCSE Graphics course I designed a kettle - a kettle so amazing I was not allowed to keep it as it was to be used on open days to show off how amazing the work of the A-Level graphics people... (I wonder if they still use it!?) Well, if I was designing it now, I could add in a feature, so that rather than turn off completely it would just dynamically draw less current when there's less to go about - the kettle would still boil, it just might a bit longer if everyone else in the nation is boiling kettles!
Aircon could be the same (and again is being done in the States) where the thermostat gets turned up automatically if there's not enough energy to go about - room gets a bit warmer, but at least there's no black/brownout!
I still want to build me a plug in frequency measuring device - it'd be interesting (from a geek point of view) to have a few dotted around the country all logging to the net to see how in sync everything is.
Well done from reading it all... if you did :-) I think I got a bit lost!
PS Yeah, I know, the science might be a bit ropey. I'm an Electronic Engineer see (who unfortunately engineers more with light at the moment, go figure?), not an Electrical one.