Yes this is true. At the moment, with prices as they are you need to be using 30-35% at night to make the most of E7. As for switching suppliers, I'm not so sure. Eon are the only suppliers I know of that allow you to go on a single rate tariff and keep the E7 meter. Other suppliers come and change it over to a single rate. If you don't use a washer, dryer and dishwasher at night, you probably aren't using close to the 30% needed. Give it a try for a quarter or two and see how it goes.

15% is usually quoted as the required amount to benefit. Many years ago, my then colleagues in Energy Supply were trying to persuade people to move to E7. The offer was to try it for 12 months, if you don't save money, we will put you back on Domestic S and refund the excess.

This seemed a no brainer, so I took up the offer. Must be over 15 years ago, in the same house etc. Check it occasionally, and yes, I am still saving money. Gas CH, but fridges and freezers run 24hrs, I have some outside security lights on all night, the dishwasher goes on overnight, and the washer and dryer if the opportunity arises. CH pump also runs at night in the cold weather.

Yes, you need to have storage heaters or use a large % of your units at nigt to benefit from economy 7 tariffs. Many suppliers don't bother about the details as long as they can persaude people to switch to them.

If you are on economy 7, it's easy to find out what it would cost on other tariffs - just use the "electricity" comparison tool on this site.

I too have been on the economy 7 tariff for over 20 years and regularly use it to heat my water, operate my dishwasher condenser dryer and washing machine. The economy 7unit rates are substantially lower during this time (currently 0130-0830) but you do pay a little more per unit for daytime consumption. However if you use it intelligently you will definitely save money overall. Some of the suppliers choose not to operate an economy 7 tariff because they lose money by it and will try and convince you to come off it and join them.You need to do your own sums based on your current consumption. They can only give you an estimation and sometimes there are gifts or other discounts that they try to lure you with but you pay for it in the end. I suggest that you move to Scottish Power as I have done. They have the best electricity price per unit and operate economy 7. Trust me, I know what I am talking about, I have been changing supplier almost annually for the past 5 years to get the best deal.

Last night I was in discussion with EON trying to get a better deal after looking at comparisons. I was surprised to be told that if I came of the dual fuel Economy 7 tariff I would immediately save about £100 pa. They explained that this tariff is only cheaper when overnight electricity is used especially night storage heaters. I have been on this Economy 7 tafiff over 20 years and have gas heating ! So, I have been paying way over te top all these years. There must be thousands of people using gas heating on an economy 7 tariff paying over the odds for electricity. Save £100 pa by coming off Economy 7 ! My supplier is EON, I have not checked this out with other suppliers. Hope I win :)