Hi Tipsy. It really depends on your site and how much wind you have, but I would raise the following concern... The viability of a wind turbine depends on four values for your electricity;
15c that you buy it for in the day time
7c you pay at night
19c that you get for the first 3,000 units you export
9c you get for every unit you export over 3,000 units per year.
At its worst point, if having geothermal means that you are using electricity at night that you could export for 19c, and which would normally have cost you 7c off-peak, your finances go haywire. On the other hand, if you have a superb site, and you are exporting more than 3,000 units, even after geothermal, then your electricity consumption is only "costing" you 9c.
If you'd like to learn more about wind turbines for the domestic market, I run short courses, but have just put the "classroom" element of these online
here.
I'm no great fan of geothermal, and find that many people are putting it into houses which are so well insulated, that the fuel cost for other fuels such as pellets, wouldn't be that much. If you spend €20K on a geothermal unit in a house that costs €3K per annum to heat, that's one thing, but if your heating bill is only €500, how can you justify it?