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Sunday 4 August 2013

Power bollocks

I was just reading Christopher Booker’s  article this morning in the Telegraph this morning.

We could soon be paying billions for this wind back-up

In it he explains the Bizarre thinking that to stop the lights going out the government is going to use all the backup diesel generators that exist in hospitals and other places that need to have an emergency supply of electricity.

The answer National Grid has come up with, only made possible by the latest computer technology and “cloud software”, is to hook up thousands of diesel generators, remotely controlled by the grid, to provide almost instantly available back-up for when the wind drops.

Personally speaking as an engineer that has spent most of his working life working with diesel generators, I think it is a disaster waiting to happen.

I don’t see how it could work.

1. All types of generators have a different “Characteristic”. Steam turbine generators, gas turbine generators, and diesel generators all respond differently to changes in load. All these generators have to supply power within a narrow frequency band either side of the grid frequency of 50 Hz. Usually within a maximum of + or - 3 Hz. How is your local hospital’s 1 Mw diesel set going to respond to the response of  a 2 Gw gas turbine. The danger is that unless the load sharing is precise (involving electronic governors these days), you could end up with a gas turbine actually “motoring” a diesel generator. In other words the DG is being driven electrically against it’s will. NOT A GOOD THING. It usually ends up with large lumps of diesel engine deciding to spread it’s self into it’s component parts. (I know. I walked past such a generator 5 seconds before it did it.). That’s your hospital fucked in the middle of winter when the wind turbines are not working.

2. All emergency generators are just that. They are arranged that if the mains power fails they are an autonomous entity.Just there to  supply the Hospital, public building, brothel, etc. Usually they are arranged that if the main supply circuit breaker drops out due to mains failure, the standby diesel generator will start and then close it’s emergency breaker onto the needed system.. QED. For safety reasons, the mains supply breaker and the emergency supply breaker are interlocked so that neither can be closed simultaneously. I’d love to know how they are going to load share between their patients and the grid?

3. As above. Does the hospital, if the rules change on electrical safety, save it’s patients or sell it’s Kws to the grid?

I feel that this is a cynical ploy by a government that has lost the plot on energy production to try and calm the average citizen, that the lights will remain on.

I have candles.