Hi gailey, I changed most of my bulbs to energy saver ones, but it doesn't have a huge impact on the bill. To figure out the savings you need to know how many units you are using for running lights. For instance, A 60 watt bulb uses one unit (that is, 1 kilowatt-hour, or kWh) in 16 hrs. Let's suppose a unit costs 15c. You will save up to seven eighths of the cost with an energy saver bulb.
So, let's suppose you replaced eight 60 watt bulbs with energy savers. Let's say on average you have all those bulbs going four hours per day (quite a lot). The cost per two-monthly bill with incandescent bulbs is only around twenty euros. With energy-saving CFLs you might get this down to two or three. A worthwhile saving of 16-17 euro but not earth-shattering. If you do the figures, you will see that your lights are unlikely to be a huge share of your bill. Using a lamp instead of your sitting room light will not make you rich.
The big energy users are always going to be those appliances that convert a lot of electricity into heat, that is, electric radiators, immersion heaters, electric showers, clothes dryers, ovens, hobs. A very easy way to save electricity is to use your microwave more. A six-minute blast of a potato in a 900W microwave costs about 1c. To bake it in your oven you could be spending 8c just to warm the oven up BEFORE you start cooking. Ok, you can't cook
everything in a microwave, but there's a surprising amount you
can. When cooking on a hob, save money by making sure you always have a lid on saucepans.
Here is a handy device:
http://www.electrisave.ie/
It tells you how much electricity you are using at any point in time. You can easily install it yourself -- it involves wrapping a clamp around the incoming wires at your electricity meter, but there are no actual electrical connections to make. It can show you energy usage in watts, cents, or grammes of CO2 ... once you configure it correctly. Unfortunately it's not cheap -- I can't remember exactly what I paid but I'm pretty sure it's something over 100 euro.
See if you can share the cost with someone... you don't need this thing running forever... after a week or two it will have mostly done its job. It's main benefit is that you can measure the real-world power consumption of each of your appliances by switching them on in isolation and watching the meter. I found it was sensitive to approximately 30 watts accuracy... not enough to reliably measure a single energy saver light bulb, but good for the big energy users. I could see that my dryer was by far the biggest culprit on the ESB bill. One immediate saving was I noticed that my oven and hob consume about 90 watts on stand by... switching off the red isolation switch saved money. I was also able to measure the efficiency of the lagging jacket on my immersion tank ... once heated fully the immersion comes on at 2kW for about three or four minutes per hour, so it averages about 100 watts. (Remember that appliances with thermostats don't always use full power all the time -- when measuring your oven, say, you have to watch how often it comes on and for how long, not just how many watts it draws when it
is on). I am out of the house for 4 days a week -- it was interesting to note that leaving my cooker on standby was about the same energy usage as leaving the immersion on all the time!
If you can't justify splashing out on the electrisave, watch the big energy items: the dryer etc. Btw, a condensing dryer will be less efficient than a vented one no matter how good its rating. On the other hand, don't throw away "waste" heat in winter or any time you are running your heating... if you fill a sink with hot water, let it stand until it goes cold: you paid to heat it -- why throw it down the plug hole? Same goes for your condenser dryer if you have one ... if it's in a separate utility room leave the door open (assuming you don't have a problem with humidity).