My understanding is that they are available wherever Apple does business, or has a store, or sells its products. So, yes, in short, they are available in Europe, too.
Refurbished Macs are available in Apple Online Stores around the world. However, the currently available selection will, of course, be different at your location. Keep in mind that the Apple Stores is country-specific, and delivery will probably be restricted to the country of purchase.
On a side note, if Apple has set up Online Stores in more than language for your country, you might want to check out both versions. A few days ago, I noticed that the products available can vary. In this case (Swiss store), it was only one model/configuration out of a dozen Macs/iPods... but you never know