@batalto We don't have batteries but it might be something we consider in future, as we are planning on getting a wind turbine (not that it would have been much good in this cold spell!). 

My current tariff that ends towards the end of March is 30.15p normally, and 7.5p for four hours, plus just 24.38p standing charge. I suspect it makes complete sense for us to stay on this, but the Cosy Tariff certainly looks good for when we need to switch. 

These are our current Cosy Tariff rates:

Posted by: @cathoderay

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Posted by: @kev-m

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I don't have a smart meter but I'm going to try and switch and have Octopus install one. 

At the risk of sounding like a tin foil hat conspiracy theorist, I have 100% resisted having a smart meter installed, despite heroic attempts by my energy supplier (EDF) to get me to have one. I say heroic, but really they are just dishonest, repeatedly claiming I have to have the 'essential' upgrade, when of course there is nothing essential about it, and I absolutely do not (yet) have to have one.

My principal objection to smart meters is not EMFs and all that, but that we are sleepwalking into a social credit system. Firms like Octopus (just like Tesco with their club card scheme) bribe and coerce people into signing up to whatever part of the social credit system it is that they are trying to implement. In Tesco's case, the bribe is significantly lower prices, the cost is Tesco know everything there is to know about your grocery shopping, from how many units of alcohol your household consumes weekly, to what your grocery carbon foot print is. There are already credit cards that allow you to (voluntarily for now) set a limit on your carbon spending, when you go over that limit, 'the card says no'...

The bribe with smart meters is lower tariffs, the cost is partly you tell your energy supplier how much energy you use and when, but the real cost is you give your supplier the ability to shut off your supply remotely. You want to warm up the house a bit? When you try to do so, you find 'the smart meter says no'... 

You can extend the dystopia very easily. What if the energy industry implodes in a not so distant energy crisis, and the government effectively nationalises the industry (as happened with the banks during the financial crash, point being these things can and do happen). The government now has remote access to control your energy supply. Is that something you really want to allow?

 

If my understanding is correct, NG would not be able to turn off electrical devices within your home without your permission, and even then the devices would need to be configured to accept the turn off signal.

Which would you rather have, selected devices such as your fridge or freezer or even your heat pump, to be turned off for a limited time period with minimal effect to your lifestyle, or to have everything switched off due to a power cut that may last for an extended period of time.

Posted by: @derek-m

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If my understanding is correct, NG would not be able to turn off electrical devices within your home without your permission, and even then the devices would need to be configured to accept the turn off signal.

That is my understanding too, because of safety concerns, eg what if you need an electrically powered medical device of some sort? Turning off the power then might 'turn off' some unfortunate person as well. The other key thing at present is they need access to your property, there is no master switch one per property, outside that they can use to turn you off. That changes when you have a smart meter, they can turn you off remotely.  

Posted by: @derek-m

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Which would you rather have, selected devices such as your fridge or freezer or even your heat pump, to be turned off for a limited time period with minimal effect to your lifestyle, or to have everything switched off due to a power cut that may last for an extended period of time.

I knew this was a contentious topic when I posted it. For me, it is about being in control of your property, not government or a corporation taking control. There are examples online of folk who signed up to a fancy smart tariff, and didn't spot in the small print (reality is most people don't read all the small print all of the time) it said their supplier could vary their supplier as the supplier saw fit. This approach is very authoritarian, and some people love it, particularly the controllers, but sometimes also the controlled. Its a bit like the smart cities thing, and the travel restrictions being put in place in cities like Oxford and Canterbury. Of course the council is doing it for both your good and the greater good, but it is still very authoritarian.

"Of all tyrannies a tyranny sincerely exercised for the good of its victims may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." 

C S Lewis, God in the Dock: Essays on Theology and Ethics, 1970 

Posted by: @scrchngwsl

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Isn't the important variable here is the average temperature of the house over the 24 hour period? If you turn it off for 3 hours, and the temp drops 3 degrees from 21C to 18C say, then turn it back on and it takes 3 hours to raise the temp back up to the set point again, then the average temperature of your house for the full 24 hours will be slightly lower (20.5C or so). Your heating requirement will therefore be slightly lower, as the Delta T between inside and outside temperatures is slightly lower. So yes you should save energy because you're effectively setting the thermostat to be half a degree lower.

The loss in efficiency from turning off and on the heat pump once per day is surely negligible compared to the reduced energy requirement from having the temp of your house be 0.5C lower.

Yes of course it is. But you will see lots of advice that warns against turning a heat pump off, ever, because it will take so much energy to start it up again. I already knew that was nonsense but this is the data to prove it. For my house...

I’ve been implementing the terrific advice from @derek-m to help de-installerise my 16kW Daikin ASHP set up, which has reduced grid consumption considerably to the point I’m on average using 1-1.5kW per hr to run the system, which is a huge reduction from last winter. In the light of this thread, one thing I think I could try to further fine-tune the system overnight settings based on how it seems to be performing thus far. The weather compensation settings currently have our house (240 dezoned internal sq m) at between 20C and 21C during the day; and we are currently seeing only around 1 degree temperature drop recorded overnight. Ambient temps are 3-10C overnight thus far in December. Setback kicks in at 10pm until 7am and is set to 18C with a programmed 5C drop in leaving water temp, but the house never gets near 18 overnight at the moment; the leaving water and return water temps equalise and drop to 29 degrees or so and the pump seems to circulate this water constantly during the setback hours, or at least that’s what I’ve observed when I can’t sleep for thinking about ASHP’s and wander into the tech room and start pressing buttons.

Below are some (grid) consumption figures

• November ‘F3’ (overnight, 11pm to 7am, so more or less equivalent to the setback period) consumption with the ASHP turned entirely off was on average 4.2 kWh per F3 period, or 0.52 kW per hr – i.e., our background non-space heating consumption;
• Switching on the ASHP in December, and using the weather compensation settings and setback as above, consumption was on average 9.3 kWh per F3 period, or 1.16 kW per hour - or an additional 5.1kWh over background, non-space heating consumpion.

 I’m still very much a newbie, and this thread set me thinking on how setback actually works:

• Does the setback use any significant energy other than the circulation pump? That is, is the additional 5.1 kWh consumed during the setback period just the circulation pump? The range of LWT setback temps on my Daikin allows up to a 10 degree reduction, so I assume that if I reduced that parameter further (e.g., from 5 to 10 degrees) consumption might increase to achieve the requested lower LWT? The manual seems to suggest that the setback function ‘allows the possibility to lower the room temperature’. That sounds suspiciously like a cooling function, which I was told wasn’t possible with my installation (i.e., a summer setting to cool rooms pumping low temp water around the UFH and rads). That said, I don't actively want to spend money to cool the rooms during winter;
• The alternative to setback seems to be to use a scheduled program to send an off/ on instruction at the desired time - e.g., an off instruction at 10pm, and an on instruction at 6am; now, I’m not clear if the current setback is helping to keep the room temps at 20-21C during the night (LWT and RWT seem to be the same - around 29C), or if that’s just the extra insulation I added to the attic over the summer. I can see two potential issues in using an off/on cycle from reading these threads – firstly, the presumed additional kw needed to fire things up at 6am when ambient temps are coolest and we have no PV; and secondly, the presumed lower room temps during the morning that would result from the weather compensation settings inputting the same amount of energy into slightly cooler rooms than at present.

Ultimately, I’d be interested to know if turning off setback saves the 5kWh (ca. 100 euros per month on the bill at present) or if its false economy due to the reasons above. I suppose the way to test this is just to have the system turn ‘off’ during the F3 hours for a week or so, monitor room temps overnight (I have a thermometer which gives hour-by-hour data), monitor comfort levels in the house during the morning, and then see what effect this is all having on grid consumption, offset by increasingly lower temperatures as we head deeper into winter. Does that sound a reasonable approach or am I missing something about how setback works v using off/on? 

Posted by: @morgan

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We are with Octopus but they can't install a smart meter for us.  We ring our meter readings in to them.

Have they said why not?  I was going to switch to them and get one.  I won't be doing this now since because I have an E7 meter I would have to go onto an E7 tariff at 44p daytime while I waited for a smart meter.  It sounds like that might be a long wait.

The more I hear about Octopus the more cynical I am about their true green credentials.

I'll stick with British Gas and my wood/coal burner.

@kev-m 

Simply because we live in a rural area and they aren't installing here at the moment.  No indication as to when that might change.

Posted by: @marzipan71

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I’ve been implementing the terrific advice from @derek-m to help de-installerise my 16kW Daikin ASHP set up, which has reduced grid consumption considerably to the point I’m on average using 1-1.5kW per hr to run the system, which is a huge reduction from last winter. In the light of this thread, one thing I think I could try to further fine-tune the system overnight settings based on how it seems to be performing thus far. The weather compensation settings currently have our house (240 dezoned internal sq m) at between 20C and 21C during the day; and we are currently seeing only around 1 degree temperature drop recorded overnight. Ambient temps are 3-10C overnight thus far in December. Setback kicks in at 10pm until 7am and is set to 18C with a programmed 5C drop in leaving water temp, but the house never gets near 18 overnight at the moment; the leaving water and return water temps equalise and drop to 29 degrees or so and the pump seems to circulate this water constantly during the setback hours, or at least that’s what I’ve observed when I can’t sleep for thinking about ASHP’s and wander into the tech room and start pressing buttons.

Below are some (grid) consumption figures

• November ‘F3’ (overnight, 11pm to 7am, so more or less equivalent to the setback period) consumption with the ASHP turned entirely off was on average 4.2 kWh per F3 period, or 0.52 kW per hr – i.e., our background non-space heating consumption;
• Switching on the ASHP in December, and using the weather compensation settings and setback as above, consumption was on average 9.3 kWh per F3 period, or 1.16 kW per hour - or an additional 5.1kWh over background, non-space heating consumpion.

 I’m still very much a newbie, and this thread set me thinking on how setback actually works:

• Does the setback use any significant energy other than the circulation pump? That is, is the additional 5.1 kWh consumed during the setback period just the circulation pump? The range of LWT setback temps on my Daikin allows up to a 10 degree reduction, so I assume that if I reduced that parameter further (e.g., from 5 to 10 degrees) consumption might increase to achieve the requested lower LWT? The manual seems to suggest that the setback function ‘allows the possibility to lower the room temperature’. That sounds suspiciously like a cooling function, which I was told wasn’t possible with my installation (i.e., a summer setting to cool rooms pumping low temp water around the UFH and rads). That said, I don't actively want to spend money to cool the rooms during winter;
• The alternative to setback seems to be to use a scheduled program to send an off/ on instruction at the desired time - e.g., an off instruction at 10pm, and an on instruction at 6am; now, I’m not clear if the current setback is helping to keep the room temps at 20-21C during the night (LWT and RWT seem to be the same - around 29C), or if that’s just the extra insulation I added to the attic over the summer. I can see two potential issues in using an off/on cycle from reading these threads – firstly, the presumed additional kw needed to fire things up at 6am when ambient temps are coolest and we have no PV; and secondly, the presumed lower room temps during the morning that would result from the weather compensation settings inputting the same amount of energy into slightly cooler rooms than at present.

Ultimately, I’d be interested to know if turning off setback saves the 5kWh (ca. 100 euros per month on the bill at present) or if its false economy due to the reasons above. I suppose the way to test this is just to have the system turn ‘off’ during the F3 hours for a week or so, monitor room temps overnight (I have a thermometer which gives hour-by-hour data), monitor comfort levels in the house during the morning, and then see what effect this is all having on grid consumption, offset by increasingly lower temperatures as we head deeper into winter. Does that sound a reasonable approach or am I missing something about how setback works v using off/on? 

I think the only way is to try it and see.  It's good you can set back the LWT.  The Ecodan can't do that other than manually and it has to be by room temperature. It's possible your house won't drop more than 2-3 degrees if well insulated.  Even at the current -5 in the UK, my house hasn't dropped to any less than 17 C between 12 and 5am and normally stays above 18.

Posted by: @cathoderay

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The other key thing at present is they need access to your property, there is no master switch one per property, outside that they can use to turn you off.

Surely they can remove the meter fuse in most homes with external meter cupboards?  And how do you know they aren't already wiring in remote controls if they want them? Smart meters seem to have fragile connections and need multiple attempts to change  settings so they're not going to be a good way to disconnect people soon: putting foil or lead in the meter cupboard would probably stop them!