Just some additional thought for you, which may help some save some money. Consider it like a petrol pump, with a few extras to consider...remove the extras from your mind, the confusion factors, and it may help.
Standing charges for gas and electricity account for around 15 to 20% of fuel cost per annum. This is a typical figure and varies for individuals depending upon their individual consumption profile.
Given this, the kWh consumed makes up the rest (typically 80%+). For many, you will be paying a single (flat) rate for both gas and electricity. So, for example, if for electricity you are paying a rate of say 11.5p/kWh and you can switch and buy for 10.5p/kWh, then by switching you are likely to save near 9% for every unit you buy. So without knowing your consumption, you can make an assessment and choose to switch or not. If you use 6000kWh per annum in the above example the difference between the prices stated is £60 per annum.
Same thought process for gas...different figures.
When considering, standing charges are usually listed as pence per day (or maths equivalent) make sure they are not unreasonably different. The more fuel you use, the less impact the standing charges have on the overall equation.
When comparing rates, make sure you are comparing like for like, ie. incl or excl VAT. For residential use that's probably about it.
It is more complex for business use so be careful.
I don't work for comparison sites, I'm a long serving electricity industry chap who has been helped a great deal by the advice on the site, so if this helps any of you that's great.