Business case for a battery

[JamesPa]

16 hours ago, SteamyTea said:

That's OK.

 

Basically, the amount of low and medium CO₂ generation is fixed, so marginal increases are dealt with burning gas. Gas has a volatile price.

Also, because we don't have enough spare RE generation, and very little storage, in the scheme if things (pumped storage is to do with load balancing), we rely on demand predictions. It is those demand predictions that set the price, and because they are predictions, some margin has to be built in.

When it goes wrong, and we have to quickly add generation, what actually happens is that the 'hot spinning reserved' come on line. It is those reserves that cost a fortune i.e. £500+/MWh.

When the prediction is the other way, and there is over production, it is often the RE that gets switched off, and that has to be paid for, often at double the going rate i.e. the strike price.

It may seem strange to switch off the low CO₂ generation, but it works out cheaper because it is easy to switch of say 10, 2 MW turbines, in different places to balance the local grids, that switch off a 100 MW CCGT and switch on a few  small diesel generators to make up the 80 MW.

 

It is more common complicated than that in reality as other factors have to be taken into account. 

One more of the pervers factors us the way that the half hour bidding auctions have elevated some RE generation that is still based in gas prices.

While this does not affect new RE generation, the legacy stuff is still generating, and because they have a lot of data, and market experience, they can decide not to bid on the day ahead market, but hope to pick up some balancing capacity, which pays better.

 

While our wholesale market has generally been very good at keeping the price down, it has caused, at times, higher CO₂ generation overall.

 

So getting back to storage, local or large scale, at the moment, it probably increases overall CO₂ grid intensity.

This will change in time with the introduction of more RE, but not for a decade or so.

 

It has been a long time since I looked at all this, but I seem to remember that grid frequency, which many people think can be used to control local storage i.e. elevated frequency, start storing, lower frequency, start delivering, does not work. 

The Grid Operator, predicts about 4 hours in advance the short term needs, and allows the frequency to rise and fall a bit. It is similar to slightly raising your house temperature because you know the night will be extra cold.

 

The whole grid balancing is a (expletive deleted)ing marvel and we should really not tinker with it too much to save a few quid on our bills. The security of supply is globally second to none. We don't want our hospitals, and traffic lights losing power at 6PM, so we can earn £2. 

It is one of the reasons that these ToU tariff trials are small scale, it will be very hard to integrate in a large scale.

Thanks for the explanation.  I cant find a business case for batteries, at least for me, and the power round here only fails rarely for short periods.  So if a battery doesn't help the environment then there is absolutely no reason to have one.   Thats why its so important to understand if it actually helps the environment, as some people claim

 

If I understand you correctly, your conclusion is that local storage, where the choice to store or not is based essentially on retail price, is currently (and wont be for perhaps a decade) of benefit to the environment, and in fact is probably harmful.

 

Is it possible to envisage a chart that demonstrates this simply without going through all the arguments?

[SteamyTea]

9 hours ago, JamesPa said:

Is it possible to envisage a chart that demonstrates this simply without going through all the arguments

No.

Mainly because there is not a simple formula i.e. y = mx+c or y = m x exp^x

 

I have a suspicion that the ToU tariffs are to enable the retail energy companies to dump over purchased energy more than doing the customers a favour.

 

 

Edited October 29 by SteamyTea

[sharpener]

1 hour ago, SteamyTea said:

I have a suspicion that the ToU tariffs are to enable the retail energy companies to dump over purchased energy more than doing the customers a favour.

 

There does seem to be some hidden agenda. If you look at the national demand profile here the big overnight dip clearly justifies trying to fill it with the traditional E7 tariff, but the fine detail in e.g. the Cosy tariff doesn't seem to be a very good match for the rest of it. Tomato offers a cheap rate from 0930 - 1130 which actually corresponds with a small hump in demand.