How to understand ESB bills
If you would like to reduce your electricity consumption, one of the first things that you need to understand is how much electricity you are using. The easiest way to do this for most people is to read your ESB bill. While this sounds very simple, many people struggle with them and prefer to just pay the damn thing and forget it. Well, this post a guide to understanding what is going on.
First rule of monitoring electricity through Irish bills, is to forget about the total price at the bottom, and focus on the units of electricity consumed. These units are called kilo-Watt-hours (kWh).
kWhs are the most common unit electricity is measure in. For me the easiest way to think about it is to think about light bulbs. If you had ten 100W bulbs, and you left them on for 1 hour, they would have consumed 1000Wh, or 1kWh (kilo meaning thousand). An old one bar heater is usually a 1kW heater, meaning if it was on for one hour, that would be 1kWh. Finally if you left one 100W bulb on for 10 hours, you would consume 1kWh.
If you monitor your electricity consumption by the bottom line on the bill, the figure can be changed by the rate you’re paying, which can change from time to time, and is out of your control. What you are really trying to do is to reduce the amount of units you are consuming.
So lets move on to bill

Lets look at your MPRN (Meter Point Reference Number) number – If you see the blue box on the top right, the 11 digit number is the specific ID for your electricity connection. If you ever have a problem, it’s the number you need. If you ever want to move supplier, it’s the number you need. It is the most important identifier your bill has. Your account number refers to your particular commercial relationship with ESB Customer Supply, but it’s the MPRN number that is the really important one.
The meter readings – the green box on the left. If you look at the numbers on your meter, these should match up. The difference between the old number and the new number is the number of kWh (or units) you consumed. ESB staff need to come to your home to read these, so sometimes they estimate them. If a reading is estimated it will have the letter “E” beside the number. The estimates are usually pretty good, but they will just make up the difference on the next bill if they were wrong.
People can also ring in the actual figures if they want. If they do, the number will have a “C” beside it. Again, you can lie to them if you want, but they’ll just come and see the next time and get you in the next bill.
The general unit price (orange box) – On the bill have shown there are two prices as the unit price changed during the billing period, but generally there will only be one price. So as you can see here, the rate for domestic electricity is 14.35cent. So that 100W bulb, left on for 10 hours, cost 14.35 cent. Does sound a lot, but the fact is, these things add up.
The standing charges (magenta box) – Again there are two because of the change in rates during the billing period. These are charges used to pay for the upkeep and running of the network. They are the same no matter how little or how much (within reason) electricity you consume. They suck.
The other interesting thing is that it is charged on a daily basis. This figure may change form bill to bill (due to longer and shorter months), and means that you can work out how much electricity you consumed on average per day.
Public Service Obligation Levy (PSO) – The PSO levy is an extra cost on all bills to pay for whatever the Commission for Energy Regulation (www.CER.ie) wants it to pay for. In the past some of it went to subsidise wind power, though the bulk of it went to subsidise the peat power stations in the midlands. They idea is to try and encourage indigenous energy sources to reduce our dependence on foreign oil, gas and coal. Thanks to that oil being so expensive at the moment it is currently Zero however. I expect we’ll see it back soon though.

Billing Period- Finally the billing period (Number 13 above) – this outlines the period your being charged for. This may be important to you if you want to see did you bill change while you were on holiday, or during Christmas, or something like that.
So, now we know what it has, lets discuss what is hasn’t got, that many other countries bill do have. These are just food for thought. They are probably all coming. Are you for them?
No time of day billing. Just like with mobile phones, electricity is more valuable during the day and less valuable at night (supply and demand and all that). In fact by using electricity during the night, using the dishwasher at night say, instead of during the day or evening, you are doing the country a massive favour. It is cleaner, cheaper and helps the Irish grid be more secure. Yet our bills do not reflect this.
No Max demand – Most other categories of electricity bills, for larger users, include a maximum demand charge. That is an extra cost based on the largest amount of electricity consumed at one time. This makes sense because if everyone in the country were to switch on their kettles, cookers and plasma screens at one time, the power stations would be in trouble. The idea of this charge would be to encourage you to keep the rate you’re using electricity down.
No ability for you to export electricity to the grid – If you put up a wind turbine on your house, and didn’t use all the electricity it generated, then tough!
BTW – Thanks to ESB for the pictures


February 8, 2008 at 11:50 am |
Patrick, in relation to the Standing Charges you wrote – “…. and means that you can work out how much electricity you consumed on average per day.”
Can you explain further please to this dumbo who’s working on a project for his brother to audit his electricity usage. We were thinking of purchasing a device like “The Owl” to monitor usage off the meter but were disappointed to learn that the device will only tell you what you’re consuming at the moment and doesn’t allow you to download data to a PC for analysis. Do you know of any better device? Or can you explain how to work out useful stats per day from the bill?
February 8, 2008 at 1:04 pm |
Hi James,
Hmmm you’re skipping on to my next post already. The meters we currently use can only accumulate the amount of electricity you are using. They have no concept of time, or rate of use. So when I said you can get an idea of your use per day, I mean Total Use/Total days = average use during the period. It’s a very crude instrument, but the best available to the average person.
What you are asking me about is referred to in the business as a Monitoring and Targeting system. Lots of industrial users use them and have sub meters on different parts of their site to breakdown what is consuming the most electricity. They are expensive however, very expensive. Examples aimed at home users are here
http://www.futumeter.ie/smart-metering.htm
The good news is smart metering as standard is on its way to Ireland. I was chatting to someone in the know other day and they were telling me that this is being fast tracked
http://www.cer.ie/en/information-centre-newsroom.aspx?article=7ac50f1d-ddde-44ea-9ce5-770946868e80
These meters should be able to give out better information than what we have already, but I’m not sure if they will have computer interfaces. They will however report back information to the ESB on a 15minutes/half hour basis, so the ESB should be able to make that data available to you (though I expect it will take them a while to get this online). Lots of large users already have this facility. I’ll have a proper post on smart meters tomorrow.
If you think that it is one or two bits of equipment that are using the power in your house, can I suggest you buy one of these
http://cgi.ebay.ie/Electricity-Power-Energy-Monitor-Meter-KWH-Watt-NEW_W0QQitemZ110221970837QQihZ001QQcategoryZ106260QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
again they don’t have a time signal or a computer interface, but they are cheap, easy, and surprisingly effective.
BTW. Thanks for the question, and let me know if there are other topics you’d like to see covered.
February 8, 2008 at 3:49 pm |
Thanks Pat, I really appreciate the great answer. You see my brother is seriously thinking about erecting his own wind turbine to help power the home/farm based business and two dwelling houses. BTW, I did a little more googling and came across this very interesting device -
http://www.diykyoto.com/
It looks like the Wattson could be what I’m looking for? Your impressions?
February 8, 2008 at 5:57 pm |
Hi James,
That looks like a really good product. Very impressive. As for wind on your bothers farm, well generally when a factory or other large user installs wind, they install it small enough that they are using every bit of the electricity. That means that if it was really windy, and the turbine was at maximum output, and the factory was at its lowest demand (is base load), then electricity generated would still be lower than what the factory was using.
The next problem is that wind turbines give out an average of 33% of their rated output, Thats average as opposed to median. Some sometimes it gives you 100%, sometimes 0%.
So what about exporting electricity? That’s a bit of a problem. You would need to get the same licences and safety equipment as a power station. The problem is that you might just electrocute some poor ESB guy. You can leak some electricity to the grid, but not get paid for it. The plan is to soften these rules, but it will take a while yet!
My advice, improve insulation. If he’s a farmer to put in a wood chip boiler. The options for electrical generation are improving fast, but there not quite there yet!
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