A fridge is the most readily available solution. It offers chilling and good insulation right from the get-go and insulation is paramount, especially if you're in a warm climate. Setting the thermostat to maximum cooling and controlling the temperature using an inkbird controller is both easy to implement and reversible.
However, if you don't have the space or wish to keep your chilled water solution, many people on the forum (myself included) tend to use shelf coolers, commonly found behind the bar in pubs to chill the product and the fonts. There are generally plenty for sale on online auction sites - search for "Cornelius Maxi" and you'll see plenty of hits for Maxi 110, Maxi 210 and Maxi 310 (the first digit being the number of product chilling coils the device has in it. Also other manufacturers have equivalent devices, such as the one I have; "Welbilt Icecore 1".
I've actually removed all the product coils from mine, so it just maintains a 10 litre bath of chilled water which I pump and recirculate through my fermenter jacket.
I'm presuming the setup for keg dispense is the same in Spain and, if you have as many bars closing over there as we do in the UK, you'll likely find a fair number up for grabs at reasonable prices.
As they are compressor-based, they should also be cheaper to run than your Peltier setup because pelters are not known for their efficiency. They do make some noise though; not particularly excessive, but I wouldn't want to sleep in the same room as one!