Passive house - average running costs

sas

Since occupying the house on May 4th we've had 2 electricity bills. Very airtight, very well insulated but high electricity bills.

First bill for €179. I was blaming this on an issue with the septic tank and my fear that a pump could have been running for days on end.

Last bill is €186. Definitely no pump issue this time. Turned out it was estimated so I read the meter. It should have been approx €200 so it's actually getting worse.

So I'm going to purchase some of those individual appliance usage monitoring devices.

We have no immersion or electric showers i.e. that rules out the usual suspects.

- All lights are LED spots or low energy light bulbs.
- All appliances are A rated
- Solar water heating covering everything up to now


The items I'm going to focus on:

- 5 year old freezer. I have my suspicions here as it's located in the utility room adjacent to a very warm services room. Will start with this one. If it appears to be using alot of electricity, I'll move it to the garage for a few days and monitor it's usage there in a more regular temperate. My theory being that the heat from the services room is putting it under pressure.

- HRV unit. The supplier stating worst case for this is 80 watts so that would account for about €20 of the bills. I tweaked the settings last night so that it sets back to the lower speed during the night and during week days which may help.

- Pump for pressurised water system

- 5 year old Plasma tv

Any thoughts on the approach appreciated because something is causing our low energy build to use alot of energy!

BryanF

Get your energy meter, 30€ or so, Clip it to the mains, and turn into an power saving anorak! But you'll diagnose the issue very quickly. Let us know how you get on.

just do it

sas wrote: »

Since occupying the house on May 4th we've had 2 electricity bills. Very airtight, very well insulated but high electricity bills.

First bill for €179. I was blaming this on an issue with the septic tank and my fear that a pump could have been running for days on end.

Last bill is €186. Definitely no pump issue this time. Turned out it was estimated so I read the meter. It should have been approx €200 so it's actually getting worse.

So I'm going to purchase some of those individual appliance usage monitoring devices.

We have no immersion or electric showers i.e. that rules out the usual suspects.

- All lights are LED spots or low energy light bulbs.
- All appliances are A rated
- Solar water heating covering everything up to now


The items I'm going to focus on:

- 5 year old freezer. I have my suspicions here as it's located in the utility room adjacent to a very warm services room. Will start with this one. If it appears to be using alot of electricity, I'll move it to the garage for a few days and monitor it's usage there in a more regular temperate. My theory being that the heat from the services room is putting it under pressure.

- HRV unit. The supplier stating worst case for this is 80 watts so that would account for about €20 of the bills. I tweaked the settings last night so that it sets back to the lower speed during the night and during week days which may help.

- Pump for pressurised water system

- 5 year old Plasma tv

Any thoughts on the approach appreciated because something is causing our low energy build to use alot of energy!

Jeez sas disappointed to hear that. I just had a check on our bills with airtricity and they come in at €81pm evened out over the year. The house is smaller at ~1,400m2 and all heat and hot water is supplied by oil.

Hard to fault your approach i.e. isolating items to measure their usage. The earlier plasma tellies are supposed to be heavy users alright and obviously the bigger the screen the bigger the usage. Electric Ireland has an appliance calculator app which may give you some hints, although probably won't tell you anything you don't know already. Sorry can't be anymore help. I hope you find the culprit;)

Do-more

sas wrote: »

So I'm going to purchase some of those individual appliance usage monitoring devices.

As a first step you could just purchase one monitor for the total supply. Then you can unplug or turn off individual items one by one and by a process of elimination work out which items are drawing what. Of course things like the freezer will only run intermittently which makes this approach a little more difficult but as a first it may well help you identify the problem items.

The Plasma TV may well be one of them as even on standby they can draw a considerable current and the older generations are real energy hogs when running when compared to the latest LED screens. There are special multi sockets available which effectively switch off current drain when TVs, DVDs, etc. are on standby.

sas

Do-more wrote: »

As a first step you could just purchase one monitor for the total supply. Then you can unplug or turn off individual items one by one and by a process of elimination work out which items are drawing what. Of course things like the freezer will only run intermittently which makes this approach a little more difficult but as a first it may well help you identify the problem items.

The Plasma TV may well be one of them as even on standby they can draw a considerable current and the older generations are real energy hogs when running when compared to the latest LED screens. There are special multi sockets available which effectively switch off current drain when TVs, DVDs, etc. are on standby.

I've ordered 2 of the individual socket monitors. If they don't throw up anything conclusive over a week monitoring then I'll add the overall supply monitor.

The plan right now is to put the 2 monitors in place on the freezer and hrv units.

Note the usage at the esb metre and leave it for a few days.

Then combine the results to see if either of them is the culprit.

After that then I'll move to the pump for the pressurised water system and I'm going to combine the everything on teh home entertainment setup into 1 socket and measure that too.

I'd expect the HRV and Freezer performances to stay consistent so after all of this I'd hope that I will be able to compare the total usage of the house for a period against the combined usage of the 4 other items i.e. pump, tv, hrv and freezer.

From 2 conversations I had last night (1 ph and 1 low energy build of similar size and occupancy) it sounds like we're running at least 50 euros more than we should be.

This is going to be fun!

brophis

Have you an electric cooker/hob? Might be another one to watch if you cook a lot.

sas

brophis wrote: »

Have you an electric cooker/hob? Might be another one to watch if you cook a lot.

Yes but as it's wired in ( not plugged in ) it's not as easy to isolate. Same issue with the ovens. Will look at them if current plan fails. Not alot can be done though if they are the source of the issue because we're not about to change our eating habits!

sydthebeat

sas wrote: »

Since occupying the house on May 4th we've had 2 electricity bills. Very airtight, very well insulated but high electricity bills.

First bill for €179. I was blaming this on an issue with the septic tank and my fear that a pump could have been running for days on end.

Last bill is €186. Definitely no pump issue this time. Turned out it was estimated so I read the meter. It should have been approx €200 so it's actually getting worse.

So I'm going to purchase some of those individual appliance usage monitoring devices.

We have no immersion or electric showers i.e. that rules out the usual suspects.

- All lights are LED spots or low energy light bulbs.
- All appliances are A rated
- Solar water heating covering everything up to now


The items I'm going to focus on:

- 5 year old freezer. I have my suspicions here as it's located in the utility room adjacent to a very warm services room. Will start with this one. If it appears to be using alot of electricity, I'll move it to the garage for a few days and monitor it's usage there in a more regular temperate. My theory being that the heat from the services room is putting it under pressure.

- HRV unit. The supplier stating worst case for this is 80 watts so that would account for about €20 of the bills. I tweaked the settings last night so that it sets back to the lower speed during the night and during week days which may help.

- Pump for pressurised water system

- 5 year old Plasma tv

Any thoughts on the approach appreciated because something is causing our low energy build to use alot of energy!

are those 2 bills definitely covering each month? or is there extra weeks included both sides of the turn of the month??

i just averaged out my esb bills for the last 9 months and they are €124.
Now thats in a very busy 2003 era 3 bed semi. I remember when i first started getting bills with my current provider the dates were all over the place... sometimes two bills in once calender moth and other time 3 months between bills.
If your bills are actually working out as 5 weeks then the figure is probably more manageable.

Actually if you worked out what your meter reading was on your first bill (ill assume 0) and what it is now... and the number of days covered we could look at your daily consumption.

eg we use 19.477 kwhr / day between 31 jan and 25 july this year.

sas

sydthebeat wrote: »

are those 2 bills definitely covering each month? or is there extra weeks included both sides of the turn of the month??

My bills cover 2 months, the first bill was for €177.59 and covered a period of 59 days

Total usage was 806 units (meter was read).

Therefore average daily usage is 13.7 kwh

I'm still hearing bills of 130 -150 for homes similar to mine for a 2 month period.

At 19kw per day you are welcome to borrow my monitors once I'm done with them. Looks like you could do with them

just do it

sydthebeat wrote: »

i just averaged out my esb bills for the last 9 months and they are €124.
Now thats in a very busy 2003 era 3 bed semi.

sydthebeat wrote: »

eg we use 19.477 kwhr / day between 31 jan and 25 july this year.

That's alot of energy! I can't see how it's any busier than mine and my bills are €81 monthly (don't know the kwhr/day but given the standing charge component it is probably not much more than half.)

Are you using electricity for heating or hot water?

Just thinking about our usage. The telly is rarely on and the kids are still young so they (or their daddy:P) aren't on playstation or xBox. On the other hand there are usually 3 meals cooked every day. And the keetle is surely boiled 10 times a day :rolleyes:

sas

Mods,

I've gone ahead and dragged this thread off point. I originally chose this for my eletricity bill posting because it was part of my ongoing experiences with my PH and went to underline that what has been said here before, people have at least as much an effect on energy usage as insulation\airtightness.

Maybe it would make sense to extract the relevant posts into a seperate thread where my battle to lower my ESB bill could be documented.

SAS

muffler

I'll do that now. Any suggestion for a thread title and which forum?

sydthebeat

how about in prices / costs forum and entitled "passive house average running costs" ?

perhaps it could become a stickied on-going thread

muffler

sydthebeat wrote: »

how about in prices / costs forum and entitled "passive house average running costs" ?

perhaps it could become a stickied on-going thread

Aye, good suggestion. I'll get cracking on this now

muffler

A few posts above moved from the live self builds thread in the C & P forum.

sas

Hi,

So I managed to borrow a meter and hooked it up to my prime suspect i.e. the freezer.

After 13 hours monitoring the freezer had used 580watts. I am going to leave it attached to it until we hit the 24 hour mark.

Extrapolating based on what I know right now. That equates to 1.1kw per day

Total Average day usage: 13.7 kw
Known usage so far: 1.1 kw
Unaccounted usage: 12.6kw

Next up HRV unit. The unit has been configured to run in it's set back mode during the day (Mon - Friday) when the house is unoccupied and also at night 7 days a week. I stupidly only decided to do this this week because of the bills. So this will have been having an impact.

So what I'll do is set the unit to run at the fixed rate over the next 24 hours so that it reflects the period of the bill I'm concerned about.

Then I'll need to determine average usage for a 24hour period during the week and a 24 hour period at the weekends in the new setup.

An interesting bit of info. A friend of mine who also has a PH has kindly shared his bill with me. They used 250kw less in the same period. So I've a target to aim for.

sas

Freezer ended it's 24 hour run at 1.15kw
HRV (running at constant rate) is currently looking around 1.8kw for 24 hours period.


Total Average day usage: 13.7 kw
Known usage so far: 2.95 kw
Unaccounted usage: 10.75 kw

Plan for the weekend is to measure the pump on the pressurised water system.
Then measure all of the usage of the tv and other items which are located together (tv, sky box, ps3, sonos bridge, telephone, router).

Once my 2 additional meters arrive progress will be alot faster in this effort.

Some else of interest. According to one of those comparison sites, I could save €20 per bill by switching supplier. I will be looking into this also.

homewardbound11

I have a low energy house in terms of heat demand. Roughly 400 euros will heat the house for the year. House is 3000.sq ft. electricity is the highest drain. 160 to 220 euros are our typical billings.It is the additional items of a larger modern house in the country. Hrv. Power to solar pump.pressurized system. Many more consuming products such as more lighting and electrical controls for heating. I know this to my loss as I designed the electrials such as CCTV, alarm, room ligtting sensors.
Anyway I did buy the owl wireless and monitored everything as it is the same old story. Don't leave items on standby. Avoid the dryer and limit dishwasher. Two small things I did find interestingwas the consumption of tv,satellite,network devices they are little power drains as I use them for recording. The second item I found was that trying to turn off everything is nigh on impossible. I got consumption down to 40 watts but at that stage even the fridge was off.
Lastly if ur in the country, your treatment system will draw power.
Almost unavoidable use so if you manage to bring down your consumption to the equivalent of a 3 bed semi in the city then I'd love to know.

muffler

If its any help Electric Ireland have both online and smartphone calculators to see where your energy is being guzzled - see here

fclauson

SAS some thoughts

firstly 20Kwh/day @ 19c / unit (a sort of SEAI average for units usage number see the link below)
would give you €1347 per annum or €115 per month

So your 13.7 usage should be costing around about €79 per month

are you sure when looking at you bill you are not rolling in standing charges which you cannot avoid. Also - are you on the day/night rate - if so you have to use somthing like 550Kwh at night before this is cheaper than just using normal units at night - so if you use less than this your are overpaying for your units.

Secondy - how are you heating you water - cannot remember what you ended up with - but that could be another source of usage

Thirdly - most supplies charge more per unit the less you use - check to see if you have not as yet tripped in to cheaper becuase you use more usage bracket

your €179 @ 806 units gives a unit price of about 22c - but this will include all your standing charges etc.

http://www.seai.ie/Publications/Statistics_Publications/Fuel_Cost_Comparison/Domestic_Fuel_Costs_Comparison_July_2012_pdf.pdf

ECO_Mental

I had an Owl monitor for a couple of months and to be honest I wouldn't be too worried about your sky box on standby or a few phone chargers left plugged in they will only account for at best 100 watts an hour.

What you need to do is get one of these monitors and work what your base load is, this is what the house runs on standby. I did this late at night or during the day when nobody is at home. My home which is a 3 bed semi with no HRV or heat pump runs at about 150 watts now if I plug out a phone charger or switch off the sky this comes down around to around 100watts. Most modern elec equipment run very low wattage on standby. This isn't where you are burning elec.

What I did notice was cooking, I have an electric hob and oven. You can take it that every ring is about 2 kW min so if you are cooking dinner every day and say you use it for an hour and use 2 rings then that could be up to 30 kWh a week and all in day rate. Weekends are even more because you might cook lunch, bake something.

I soon realized that after you get all energy saving bulbs and try and switch off lights, use night saver elec for the dishwasher and clothes washing you there is not much you can do. But it is helpful and peace of mind to find out exactly where you are burning the elec.

sas

homewardbound11 wrote: »

.It is the additional items of a larger modern house in the country. Hrv. Power to solar pump.pressurized system. Many more consuming products such as more lighting and electrical controls for heating.

Bought an OWL myself on saturday. Have to agree with all of the above, starting to look like that i.e. more spec. means power.

homewardbound11 wrote: »

Lastly if ur in the country, your treatment system will draw power.

I've a regular septic tank so no power needed there. I do however have a percolation area higher than my tank so I've a pump that runs several times a day to drive the effluent up to it.

sas

fclauson wrote: »

SAS some thoughts

firstly 20Kwh/day @ 19c / unit (a sort of SEAI average for units usage number see the link below)
would give you €1347 per annum or €115 per month

So your 13.7 usage should be costing around about €79 per month

are you sure when looking at you bill you are not rolling in standing charges which you cannot avoid.

I am including the standing charges but so is everyone else I am asking when comparing bills so it makes sense. However, I've moved to comparing total kwh per bill because there is such a variance in rates being paid based on when people moved in over the last year or so and who their supplier is.

Bottom line for me is that a friend of mine with a slightly larger PH with a bigger familly sent me his last bill. He used 250 kwh less than me. That's alot.

fclauson wrote: »

Also - are you on the day/night rate - if so you have to use somthing like 550Kwh at night before this is cheaper than just using normal units at night - so if you use less than this your are overpaying for your units.

No night rate. The figure I heard for benefiting from night rate is 4kwh per 365 days a year. That's alot. I haven't yet actually run the math on mine though.

fclauson wrote: »

Secondy - how are you heating you water - cannot remember what you ended up with - but that could be another source of usage

Entirely solar. I actually don't have an immersion heater.

fclauson wrote: »

Thirdly - most supplies charge more per unit the less you use - check to see if you have not as yet tripped in to cheaper becuase you use more usage bracket

Wasn't aware of this. You got any links to this info?

sas

ECO_Mental wrote: »

I had an Owl monitor for a couple of months and to be honest I wouldn't be too worried about your sky box on standby or a few phone chargers left plugged in they will only account for at best 100 watts an hour.

What you need to do is get one of these monitors and work what your base load is, this is what the house runs on standby. I did this late at night or during the day when nobody is at home. My home which is a 3 bed semi with no HRV or heat pump runs at about 150 watts now if I plug out a phone charger or switch off the sky this comes down around to around 100watts. Most modern elec equipment run very low wattage on standby. This isn't where you are burning elec.

I did buy an Owl in saturday. My standby rate is 280watts. I need to do the turn it all off experiment though.

ECO_Mental wrote: »

What I did notice was cooking, I have an electric hob and oven. You can take it that every ring is about 2 kW min so if you are cooking dinner every day and say you use it for an hour and use 2 rings then that could be up to 30 kWh a week and all in day rate. Weekends are even more because you might cook lunch, bake something.

This is exactly what I discovered thanks to the OWL. The oven and hob devour electricity. I plugged the OWL in around 4pm on saturday. We cooked saturday evening and again sunday morning. By 4pm on sunday we'd used 20kwh. Ultimately there isn't alot we can do about this. Our cooking habits are what they are.

ECO_Mental wrote: »

I soon realized that after you get all energy saving bulbs and try and switch off lights, use night saver elec for the dishwasher and clothes washing you there is not much you can do. But it is helpful and peace of mind to find out exactly where you are burning the elec.

Agree. I'm very quickly arriving at the position that it is what it is.

Over time things may improve slightly in terms of kwh.

Discovered that my oldish plasma tv draws 280watts. It easily on for 8 hours of the 24hrs where we used 20kwh. That's 2.24 kwh straight away.

Was pleasantly surprised to see how little the washing machine uses. 420watts per 40 degree wash (cold fill).

Thanks for all the feedback everyone.

Do-more

sas wrote: »

The oven and hob devour electricity. I plugged the OWL in around 4pm on saturday. We cooked saturday evening and again sunday morning. By 4pm on sunday we'd used 20kwh.

Just wondering if it's a standard electric hob you have or induction?

sas

Do-more wrote: »

Just wondering if it's a standard electric hob you have or induction?

Induction

fclauson

sas wrote: »

No night rate. The figure I heard for benefiting from night rate is 4kwh per 365 days a year. That's alot. I haven't yet actually run the math on mine though.

maybe I have my maths wrong - but to quote ESB (there are other fine electrical providers out there who offer the same sort of thing)

NOTE: Customers who move from the 24 Hour standard to NightSaver standard price plan can enjoy annual savings of € 99 (inc VAT). This is based on customers with an average annual usage of 5,300kWhs and 40% night usage.

Wasn't aware of this. You got any links to this info?

Its the standing charge which gets varied if you are a "low user" - not certain if this is done up the front and then lowered or done at end of period.

sas

fclauson wrote: »

NOTE: Customers who move from the 24 Hour standard to NightSaver standard price plan can enjoy annual savings of € 99 (inc VAT). This is based on customers with an average annual usage of 5,300kWhs and 40% night usage.

I didn't do that math, I read the 4kw figure somewhere.

40% usage at night is unrealistic for alot of people in my opinion unless you are on electrical based heating, be that a heatpump or storage heaters. Either that or you are heavily dependent on an immersion for hot water.

I'm currently averaging 20% night rate. I have a day and night tracker on my meter so I can keep an eye on it and see if it would be possible for me to get to the 40%. I'm not on an actual night rate tarriff though as it stands.

sas

Hi,

To bring this to closure. We're averaging 13.5kw per day consistently. We are all making conscious efforts to turn tvs off etc. but it's not making meaningful difference.

Our cooking appliances are devouring it. As they are new they aren't going to be changed anytime soon so that option is out.

I will continue to monitor over the next year.

Thanks for your thoughts.

SAS

Outkast_IRE

sas wrote: »

Hi,

To bring this to closure. We're averaging 13.5kw per day consistently. We are all making conscious efforts to turn tvs off etc. but it's not making meaningful difference.

Our cooking appliances are devouring it. As they are new they aren't going to be changed anytime soon so that option is out.

I will continue to monitor over the next year.

Thanks for your thoughts.

SAS

Yup any use of energy to create heat will drive it up big time.
Theres no winning if you get a gas hob/oven thats another bill anyway.

sydthebeat

if its any consolation, the extra energy created as heat from cooking etc is being used directly to heat your house.