All depends on your tarrif and the billing period.
Best tarrif will depend on how frequently you are out and how much electricity you use.
We use the Connect@ Electrity Holidays plan. This gives you a lower fixed cost and discount on the fixed costs. No discounts on electricity used. This works for us as we are only out 5-6 weeks per annum.
We get our bills every two months and the total bill is normally around 60-70 euros or 30-35 euros per month.
Actual consumption makes little difference as the majority is supply charge and fixed costs.