... Also please is there anything I need to be careful of when refitting?
Yes, if my memory serves me correctly, there are special procedures otherwise it won't work or work properly. I'll have to check the Renault manuals to refresh my memory though... Just checked and there is a special document on replacing alternators - if you email me directly (not in this forum) I can email you a copy. My memory also says you have to connect the Clip afterwards to instruct the computer of the type and size alternator fitted.
Is there any other alternator that will fit?
Not to my knowledge.
Why does it need such a high power?
Because in order to heat the interior of the Renault built Espace IV, quickly, they have fitted some electric heaters and when they are all on, they can consume 1 kilowatt of power! It's like a home electric bar fire, with four bars and it will switch in between one and four bars depending on other information. This is all controlled by the internal computer and this is why there is a set procedure when replacing it. It is also why the alternator is water cooled - we actually had one producing 172 amps when we were doing the training some years ago, and they need the water cooling with this much power - air cooling is not enough.
The other thing is to make sure you have no air locks in the cooling system when you refill it.
Roy