I know this thread is getting old but I thought I would offer my opinion on the matter from personal experiences.
As you may know I am an electrician covering the Costa Del Sol and Almeria, so I meet many different clients and they tell me thier experiences, as of yet, I am yet to meet one satisfied Iberswitch customer. Why? Well, to start with the savings they advertise never reflect what you can actually physically get. I was with a client today and she was discussing with me that she wanted to change provider, and I talked her through it, and Ill take you guys through it as well;
There is a MINIMUM that power by Kw/h can be sold at, currently i THINK 0.1423 cents. It cannot be sold cheaper, stipulated by the goverment, however, companies can offer you a discount on your Potencia Contratada, your TARIFF. This however is approximately only 10euros a month for a 5.75kw property (25amp).
Iberdrola offer 5% off that charge, equalling 50 cents a month discount on that. Also, as of me checking today, they will not raise prices at all for 12 months, so you will continue to pay 0.1423cents all year, now price rises are discussed every 6 months here in Spain, It didnt increase at Christmas so you can be fairly sure it will increase in June. My educated guess from experience is that it will raise to nearly 0.1600 cents KW/h. Now, if you work it out. if you use 500kw/h at the moment for the month of FEB, you would be charged the following:
500KW/h x 0.1423 = €71.15
With a price increase to .1600cents, you would pay
500KW/h x 0.1600 = €80.00
So effectively you CAN save nearly 9€ a month during the 6 months with no price rises which equals a total saving over a year of
(54€ + .50centsdiscount on power tarriff x 12months = 6€)
So you would save €60 a year. Exactly what Iberswitch cost in the first place.
Now I am not one to bash a company, look, Iberswitch, I understand you are a business and businesses are to make money and be profitable. Thats fine, I really dont mind. However, I am just putting across the facts that I have and know are true. You DO supply a service, switching people over, and yes, if people want they pay you for that service. But you must not promise savings that are impossible. Its possible to save different amounts with different suppliers, but to say you can half your bill, is just not right.
If anyone IS interested in changing company, I dont wish to sound to much like im selling here or anything, but I at Costa Del Sky offer a electrical installation saftey test, which takes around an hour, testing all your electrics, making sure everything is safe and repairing any faults, and also, after its finished, I will happily take a look over your bill, and work out with you what you could save by changing provider. Basically Ill show you the math I just did above but for your situation. If you fancy changing company, its included in the 40€, so really you dont pay just for changing company, you get me to go to your house, check your electrics, repair any problems AND talk you through changing suppliers and do it for you if you like, all for that 40€.
If you would just like to change companies and nothing more, than, perhaps you may be interested in Iberswitch, at 30€ + IVA, they can change you over, then if you no longer want to pay thier monthly charge, scrap them, they did thier service you initially paid them for.
I hope this is informative, it took a while to write and I hope that clears up what can be saved by changing providers.