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Random Renewables Thread



  • Registered Users Posts: 6,507 ✭✭✭ the_amazing_raisin

    For anyone who has any form of heat recovery ventilation, I'm curious as to what happens if the house gets overheated in winter?

    Say you're cooking Christmas dinner for a bunch of people. I've noticed that something like a kitchen/dining room will get pretty warm with a bunch of cooking appliances going full blast, not to mention a bunch of guests trying to work their way through the wine cellar

    I guess the ventilation will try to distribute the heat to other rooms which are cooler, but will it eventually start bypassing the heat recovery and letting some cold air in?

    Or will it just try to keep as much heat in the house as possible and wait for it to eventually dissipate after all the guests have passed out from a combination of turkey, wine and heat?

  • Registered Users Posts: 2,978 ✭✭✭ randombar

    Just checked the time on my day night meter based on a comment here.

    looks like my time is 3 hours fast on the clock.

    Currently says 00:40 and it’s 21:40

    Was costing me a bit on charging the car and batteries!!!

  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 59,711 CMod ✭✭✭✭ unkel

    That's bad. I wouldn't let that rest. Contact ESB networks and demand a massive payout based on all your time of charging the car and other stuff at "night" rate when you were charged full day rates. Shouldn't be that hard to do some sums in Excel. It won't go anywhere of course, but if you end up in the small claims court you can be almost guaranteed that you will win the case (provided the sum owed to you is not more than €2500)

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022

  • Registered Users Posts: 2,978 ✭✭✭ randombar

    It is a dose all right but I think would be more of a dose going forward.

    Car was the main one really.

    I'd it set to stop charging at 8 and it's a 3.3kw charger so 6.6 units maybe twice a week at 0.22c instead of 0.11c

    Costed me an extra 1.45 per week the past while I'd say.

    Not sure if I want to flag it though cause I'm wondering if the nightsaver kicking in at 9 might work in my favour?

  • Registered Users Posts: 445 ✭✭ DC999

    Some lucky souls in the UK are getting a 1 year trial to test a new V2H charger before it goes to market. Would have loved to try that over here myself. They get it at a savage discount and get to keep it afterwards. Only Nissans for now, 'compatible CHAdeMO-based electric vehicle: Nissan LEAF (model year 2013 onwards), Nissan e-NV200'. Goes up to speeds of 6kw in and out.

    Vehicle To Home | Vehicle-to-Home (V2H) Bidirectional Chargers | INDRA

    Sure, cons are there's wear and tear on the battery. And car has to be in the driveway. But pros is it's largest house battery you'd ever have. And batteries are paid for to be used (whether in a car or house).

    If V2H became a runner, could even get a written off EV (that battery was good / safe in) and land it in a shed somewhere connected to a V2H charger. Then run forever more on night rate & solar :)

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  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 59,711 CMod ✭✭✭✭ unkel

    That's not new, that existed back 10 years ago. The nuclear disaster at Fukushima brought it on. That's why only CHAdeMO cars can be used.

    That said, here we are 10 years later and there are no other systems available for easy V2H. If I had an old Leaf or Outlander PHEV, for sure I would have signed up for that as long as I wouldn't have to pay for the hardware. The DC CHAdeMO bi-directional charger alone costs about €3k last time I looked

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022

  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 59,711 CMod ✭✭✭✭ unkel

    BTW many of us use a DIY powerwall in a very similar way. Unfortunately, V2H is not really where we need to go, we need to go V2G. Basically buy electricity when it is cheap and green off peak (or make your own) and sell it back to the grid at peak times when it's really expensive (and dirty to produce from fossil fuels)

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022

  • Moderators, Sports Moderators Posts: 16,446 Mod ✭✭✭✭ slave1

    As Unkel says, been around for nearly a decade in Japan, this was the biggest advantage CHAdeMO had/has over CCS, CHAdeMO is bi-directional.

    A 24kWh Nissan Leaf had around 21.5-22.5kWh available (Nissan never confirmed) but at this stage those batteries are well degraded, lets say to around 14-15kWh. This car would cost approximately €7k. A 20kWh DIY setup with much safer batteries costs around €2.5k.

    Financially speaking it's all too late, the world has moved on

  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 59,711 CMod ✭✭✭✭ unkel

    A Leaf sold on DD at the weekend for €4k, not a bad option at all if you could get the V2H hardware (worth about the same) installed for free for some sort of trial though 😂

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022

  • Registered Users Posts: 2,980 ✭✭✭ graememk

    Interesting video on lengionella

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  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 59,711 CMod ✭✭✭✭ unkel

    Excellent. I realised a long time ago that the standard advice to heat up your entire cylinder to 60C at least once a week was way OTT.

    His added strong points are that there are rarely / never victims in domestic houses, quite likely there is legionalla, but simply not enough of it to make you sick. And that there is more risk from scalding from hot water than from getting sick from legionella

    After watching that video, I'll never ever worry about legionella again or do any extra heating up because of it. We have a super high turnover of our cylinder although it's big. And the only time we would be absent from the house for a few weeks would be the summer, upon our return the entire cylinder is always at the max of 60C because our solar thermal setup so not a single little monster would still be alive 😁

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022

  • Registered Users Posts: 445 ✭✭ DC999

    Was bingeing on him / them when was supposed to be sleeping last night. Have some class stuff. Did one on if it’s better to run heating 24*7 – which seems nutttttssss of course. And it came down to ‘it depends’ – it works in some cases and not in others. He said it’s more down to thermal mass (having solid stuff that can absorb the heat and release slowly) than insulation levels. And there’s less wear on boiler as it’s tipping along slowly (condensing boiler which I don’t have). House not overshooting on temp as heating catches up like mad...

    But understandably he said don’t do it if heating from electricity at day rate costs – would cost mad money (bar the lucky souls here with 8c night rate and larger batteries). Was more focused on heatpumps and condensing boilers. 

  • Registered Users Posts: 1,625 ✭✭✭ bullit_dodger

    Yeah, that one about turning off when leaving the house verses leaving on 24x7 has been banging about for years. Comes up a lot on the channels. It's not "a depends" really, you should knock it off IMHO

    The reason is pretty straightforward if you think about "your house as a system". We know that no matter what you do (insulate etc) will have energy losses from your house. If you didn't then if you heated it to 21C it would remain forever at 21C even though you turned off your heating system.

    If you take a ridiculous example of extrapolating it out and go on holliers in January for 2 weeks. Naturally you wouldn't leave on the heating as you'd be paying for those loses even though there's no one in the house. Stands to reason then that there is some "tipping point" shorter than 2 weeks where it might be favorable to leave on, verses turning it off and back on again. So, what would that time be then, if it was better in fact.

    With normal losses the time that it takes my living room to cool down is about 2 hrs (depends of course on how cold it is outside etc) but generally speaking. So after 2 hrs the energy I've put into the room at zero hour is mostly gone. So, if you're leaving the house for more than 2 hrs, then you'd be putting energy into the room which is otherwise not used (by you) in feeling warm, i.e. wasting energy. If you left the house for less that that, then there might be an argument as you have to heat up piping etc.

    Course heat pumps change the landscape as they don't work the same way as boilers (above). They tend to move the temp slowly, but even then, I'd turn it off if leaving for work and probably turn back on via remote control/timer 2 hrs before coming home.

  • Registered Users Posts: 445 ✭✭ DC999

    For me too, it's a turn it off and have it on a timer / turn on remotely. That said I'm messing with a small electric rad in the ‘core’ of the house - sitting room + kitchen. To stop the temp getting too low. We get decent solar gain in there so once it’s sunny it needs little heat. Otherwise it takes too long to heat up when kids get back from school and then gets too warm. Weather is still mild but at mo that 400w heater keeps the 2 rooms warm and only use 1.5kWh a day. Gonna get an infrared rad to try for WFH room. Rest of the gaff can freeze for now 😊

    But he did show some cases where it was close energy wise. Was down to the efficiency dropping on the combi boiler or heatpump or UFH when they’re run too hard or not the right setup for the house. I’ve none of those but was watching out of interest. Same analogy as driving fast somewhere. Get there faster (room hotter quicker) but use more juice V slow and steady.

    We’ve put our money into an EV and solar. So house insulation wrap and new windows + non gas boiler are not on the cards for years (but are weaning off gas where we can).

  • Registered Users Posts: 2,980 ✭✭✭ graememk

    I'd be in the camp of keeping the house "warm"

    The majority of my heat is from solid fuel, and I'm usually in for food at 11& 1ish so it's not hard to keep it topped up/ticking over.

    I do have the house to set back to 18 during the day and at night.

    Currently heating to 20c ATM and so I'm still playing about with that. Possibly will bump that to 21 for the living room.. and maybe the hall. As the heat can drift into the other rooms.

  • Registered Users Posts: 1,625 ✭✭✭ bullit_dodger

    Course a lot of that Graeme is where the thermostats are located inside the room as well as the room itself. Your like me with the Tado's and the one in my living room (colder room in general with 3 external walls) needs to be set to 21C while the TV room which only has one external wall is comfortable with 19-20C.

  • Registered Users Posts: 445 ✭✭ DC999

    Part of the argument in video was if people are in the house at random times (like you there), then a more constant temp if better. And that 'set back' outside the main hours saves costs of course.

  • Registered Users Posts: 6,507 ✭✭✭ the_amazing_raisin

    I'm in the leaving it on all the time and controlling with thermostats camp. I've got it set to 19C most of the time and will turn it up if the house is cold

    The controller is on a timer where it switches off around the middle of the day for a couple of hours. This gives us a bit of time to open the windows to vent and air the house

    The other advantage is if I forget to set the thermostat down the timer will automatically reset it since it controls both

    I'd second that thermostat placement is critical, and I'm in the camp where room by room thermostats are a good idea. Our upstairs is controlled by one of those junk mechanical thermostats in the front bedroom which is north facing. What we find is that when the wind is out of the south the back rooms get cold because of the draft.

    To get the back rooms warm we need to set the heating high enough that the front bedroom gets unbearably hot

    Having individual room controls would help a lot with this

  • Registered Users Posts: 6,507 ✭✭✭ the_amazing_raisin

    Can you link to that video? I was looking through the channel history but couldn't spot it

  • Registered Users Posts: 454 ✭✭ silver_sky

    I've only got a thermostat in the hall downstairs and one on landing upstairs. No individual room thermostats. :( Still trying to get it dialled in. I added zigbee thermometers into most rooms and have been tracking the temperatures - not connected to the heating system obviously. I'm seeing some patterns in the temperature when it falls below what I want so will set the heating around those times. It's quite different for downstairs vs upstairs.

    I need to sort out ventilation as that's one issue I'm sort of battling against - those natural vents are a joke. The sitting room seems to fair worse with draughts. Right on the back of your neck when sitting on the couch isn't pleasant. :(

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  • Registered Users Posts: 6,507 ✭✭✭ the_amazing_raisin

    Sounds similar to my house, take a nicely insulated and airtight house and then drill a big hole through every wall to let the cold breeze in

    I'm considering an MHRV for similar reasons, want to improve air quality and stop the cold draughts

    I'm hoping it'll add a bit of sound insulation as well as I get the noise of planes flying over quite a lot during the night

  • Registered Users Posts: 1,625 ✭✭✭ bullit_dodger

    The Tado system is pretty good. If you already have thermostatic valves on your rads, you can fit them yourself in about 60 seconds without a wrench even. Effectively creating a "Zone" for every rad (and you can link rads into rooms) etc. Control the heating from your phone or a thermostat, or on the rads themselves. e.g if I'm upstairs and turn one one of the rads and the system is "off" then it will wirelessly turn on the boiler.

    tado° Smart Radiator Thermostat - Wifi Add-On Smart Radiator Valve For Digital Multi-Room Control, Easy Installation, Save Heating Costs - Works With Alexa, Siri, And Google Assistant : DIY & Tools

    Full system is....

    tado° Wireless Smart Thermostat Starter Kit V3+ Incl. Stand – Full Control Over Your Boiler And Hot Water From Anywhere, Save Energy, Easy DIY Installation - Works With Amazon Alexa, Siri, and Google : DIY & Tools

    Recommend these.

  • Registered Users Posts: 445 ✭✭ DC999

  • Registered Users Posts: 454 ✭✭ silver_sky

    Yeah that's it exactly. Very new and well insulated house... then some annoying draughts. :( Also have some noise but it's mostly cars, or even if someone is standing on the road outside talking you can hear it very clear (depending on the room).

    I currently have a wired EPH 3-zone system with upstairs, downstairs, and water. It has the motorised valves on the tank and heating loops also. How would this work?

    Most rads have TRV's except for hallway and bathrooms. I leave the bathrooms valves either off entirely or on very low level. I need to get the hallway changed to a TRV either way.

  • Registered Users Posts: 2,980 ✭✭✭ graememk

    If you switch to tado valves only you can just the valves (need the hub too)

    Keep your original timer, only drawback is that the tado can't call for heat.

    Wait until black Friday or prime day for deals on tado.

    Next level is switch your timer to the tado controller. Then the tado can control your boiler (either by a simple relay or fancier communication if the boiler supports it)

    By default it can control 1 zone and water. Simply the 2 zones can be joined, as one, if all rads are on TRVs. It then can call for heat on demand,

    Extra zones can be controlled by the tado wired thermostats, but you need to email them to setup a separate zone in your account,

  • Registered Users Posts: 2,980 ✭✭✭ graememk

    Usually enjoy these videos, very neat work but am I watching this right..

    They are putting in an eddi.. to monitor their export?

    Surely the solax inverter with a battery would have some monitoring..

    Or the FIT meter?

    An eddi is a v expensive energy monitor.

    That channel already has installed an emon pi which is a fraction of the price...

    But if the customer wants it.. the customer can get it if they please...

  • Registered Users Posts: 6,507 ✭✭✭ the_amazing_raisin

    Has anyone ever looked into biomass powered micro CHP for a home? I was thinking of looking into something which can power me through the coldest few months where there's no hope of solar PV meeting me needs

    Micro CHP seems like a possibility since it reduces the heating load and could also charge batteries. However most of them are gas powered and I've no gas supply to my home.

    So it's either bottled gas or some other fuel like biomass

    I've seen systems out there but they're focused on commercial buildings and are way too much power for my needs

  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 59,711 CMod ✭✭✭✭ unkel

    Forget it. Bottled gas is ludicrously expensive. If you have a modern house with HP heating, you don't need to use fossil fuels, maximise PV first, maybe go bigger battery second. But the latter ONLY if you DIY and get the parts for reasonable prices. I don't get all those people coming out of the woodwork in the last year or so, now we have FIT, that spend a fortune on a battery that will never pay for itself

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022

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  • Registered Users Posts: 2,980 ✭✭✭ graememk

    To get electrical generation from heat.. from burning stuff is difficult on small scale. Especially at house scale for heat and power.

    By the time your generating enough power to be useful, you have waaay too much heat.

    Usually electric generation is getting something to spin, so turbines, engines, so a Stirling engine is a candidate.

    Tec's/peltier modules are solid state and can generate power if you could "cool" the other side.Id say its doable.. but not worth the headache!

    Maybe something that could sit on top of a stove and have a massive heat sink on it.. you might be able to charge your phone!

    Better off just insulating!