EV tariff for hot tub (no ev)

CRAIGEMMA

After calculating shifting usage etc I came to conclusion a fixed tariff at 20.38 and standing charge 45p with fuse was best option 

barker77

dunstonh said:

There is also the option for economy 7.

Is it possible to get economy 7 with a smart meter if never had it before ? Wasn’t sure if needed different wiring etc 

lohr500

barker77 said:

dunstonh said:

There is also the option for economy 7.

Is it possible to get economy 7 with a smart meter if never had it before ? Wasn’t sure if needed different wiring etc 

It is possible.

Traditionally, Economy 7 meters were usually set up such that you had a dedicated distribution board/fuse box which was only live during the off-peak hours. Things like storage heaters were connected to this second fuse box so they only started heating up in the off-peak window. The main fuse box stayed live all the time and also benefited from the cheap off-peak rates. Switching of the off-peak fuse box was controlled either by a mechanical or radio controlled time switch, or directly by the meter. The meter would have two registers. One recording peak hour usage, the other off-peak.

However a smart Economy 7 meter can be fitted to an existing single rate meter installation without any modification.

The only thing is that you wouldn't have the benefit of a dedicated meter controlled fuse box which is only energised during the off-peak window.
Individual appliance timers have to be used to switch on and off any devices that you want to use only during the off-peak period. 

It can work well, especially if you already have timer control on things like immersion heaters, washing machines, dishwashers, etc.

It is what I do. 

The main drawback is that you have to make sure any timer clocks are set to the correct time and checked regularly so they don't drift from the off-peak time. Also some Economy 7 supply times remain on GMT all year long, so depending on the make of the time switch the timers and times may need changing when we switch to and from BST. 

Hope this makes sense.

subjecttocontract

Hot tubs use significantly less energy than would be needed to recharge an EV. It would be obvious by looking at the consumption that the customer is not charging an EV. 

Grumpy_chap

CRAIGEMMA said:

After calculating shifting usage etc I came to conclusion a fixed tariff at 20.38 and standing charge 45p with fuse was best option 

I'd quite like that - the best EDF will give me is over 26 pence per kWh and over 45 pence daily standing charge. 6 pence per kWh would be a big saving.

With regard to the question about heating the hot tub during overnight low rate from an EV tariff.  Does that actually work out more cost effective overall?  Heat at night on low rate.  The hut tub will then be nice and warm at 7 am in the morning and losing heat all day until the OP decides to use the hot tub.  It will need top-up heating to keep it warm or to re-heat just ahead of use.  Presumably the highest heat load is when the lid is off and the hot tub in use.  Presumably that will not be during the hours of low EV rate electricity.

Obviously, as this is MSE, the most MSE thing to do is turn off the hot tub and use it cold as a paddling pool.

QrizB

CRAIGEMMA said:

After calculating shifting usage etc I came to conclusion a fixed tariff at 20.38 and standing charge 45p with fuse was best option 

Glad you've found a tariff that works for you!

lohr500

Grumpy_chap said:

CRAIGEMMA said:

After calculating shifting usage etc I came to conclusion a fixed tariff at 20.38 and standing charge 45p with fuse was best option 

I'd quite like that - the best EDF will give me is over 26 pence per kWh and over 45 pence daily standing charge. 6 pence per kWh would be a big saving.

With regard to the question about heating the hot tub during overnight low rate from an EV tariff.  Does that actually work out more cost effective overall?  Heat at night on low rate.  The hut tub will then be nice and warm at 7 am in the morning and losing heat all day until the OP decides to use the hot tub.  It will need top-up heating to keep it warm or to re-heat just ahead of use.  Presumably the highest heat load is when the lid is off and the hot tub in use.  Presumably that will not be during the hours of low EV rate electricity.

Obviously, as this is MSE, the most MSE thing to do is turn off the hot tub and use it cold as a paddling pool.

Over the past few weeks since installing it, I've been monitoring the heat loss on our 1300 litre foam walled Lay Z Spa Toronto hot tub.

With daytime temperatures of around 12 deg C and moderate winds in a relatively exposed location it has only been losing 2 deg C between 08:30 and 18:00 each day.

The heater is set to 40C, which means it is still at a very pleasant 38C when we start using it in the early evening.

In the past few days with the seasonally abnormal higher ambient temperature it has only lost 1C through the days. 

It is sat on an insulating matting base and has the additional all over thermal cover fitted when not in use.

With 30 minutes use, including running the air jets for some of the time, the temperature then drops by another deg or two, but still acceptable. I think the air jets accelerate the heat loss though as you end up blowing lots of ambient temperature air through the water.

The heater is scheduled to switch on daily for just under 7 hours, coinciding with the off-peak Eco7 timings.

I'm sure if it was used for several hours and left uncovered for an extended period through the day, then the temperature would drop more, perhaps to the point where more heat may be required.

But for our usage pattern, the overnight heating schedule is working well so far.

powerful_Rogue

lohr500 said:

Grumpy_chap said:

CRAIGEMMA said:

After calculating shifting usage etc I came to conclusion a fixed tariff at 20.38 and standing charge 45p with fuse was best option 

I'd quite like that - the best EDF will give me is over 26 pence per kWh and over 45 pence daily standing charge. 6 pence per kWh would be a big saving.

With regard to the question about heating the hot tub during overnight low rate from an EV tariff.  Does that actually work out more cost effective overall?  Heat at night on low rate.  The hut tub will then be nice and warm at 7 am in the morning and losing heat all day until the OP decides to use the hot tub.  It will need top-up heating to keep it warm or to re-heat just ahead of use.  Presumably the highest heat load is when the lid is off and the hot tub in use.  Presumably that will not be during the hours of low EV rate electricity.

Obviously, as this is MSE, the most MSE thing to do is turn off the hot tub and use it cold as a paddling pool.

Over the past few weeks since installing it, I've been monitoring the heat loss on our 1300 litre foam walled Lay Z Spa Toronto hot tub.

With daytime temperatures of around 12 deg C and moderate winds in a relatively exposed location it has only been losing 2 deg C between 08:30 and 18:00 each day.

The heater is set to 40C, which means it is still at a very pleasant 38C when we start using it in the early evening.

In the past few days with the seasonally abnormal higher ambient temperature it has only lost 1C through the days. 

It is sat on an insulating matting base and has the additional all over thermal cover fitted when not in use.

With 30 minutes use, including running the air jets for some of the time, the temperature then drops by another deg or two, but still acceptable. I think the air jets accelerate the heat loss though as you end up blowing lots of ambient temperature air through the water.

The heater is scheduled to switch on daily for just under 7 hours, coinciding with the off-peak Eco7 timings.

I'm sure if it was used for several hours and left uncovered for an extended period through the day, then the temperature would drop more, perhaps to the point where more heat may be required.

But for our usage pattern, the overnight heating schedule is working well so far.

lohr500 said:

Grumpy_chap said:

CRAIGEMMA said:

After calculating shifting usage etc I came to conclusion a fixed tariff at 20.38 and standing charge 45p with fuse was best option 

I'd quite like that - the best EDF will give me is over 26 pence per kWh and over 45 pence daily standing charge. 6 pence per kWh would be a big saving.

With regard to the question about heating the hot tub during overnight low rate from an EV tariff.  Does that actually work out more cost effective overall?  Heat at night on low rate.  The hut tub will then be nice and warm at 7 am in the morning and losing heat all day until the OP decides to use the hot tub.  It will need top-up heating to keep it warm or to re-heat just ahead of use.  Presumably the highest heat load is when the lid is off and the hot tub in use.  Presumably that will not be during the hours of low EV rate electricity.

Obviously, as this is MSE, the most MSE thing to do is turn off the hot tub and use it cold as a paddling pool.

Over the past few weeks since installing it, I've been monitoring the heat loss on our 1300 litre foam walled Lay Z Spa Toronto hot tub.

With daytime temperatures of around 12 deg C and moderate winds in a relatively exposed location it has only been losing 2 deg C between 08:30 and 18:00 each day.

The heater is set to 40C, which means it is still at a very pleasant 38C when we start using it in the early evening.

In the past few days with the seasonally abnormal higher ambient temperature it has only lost 1C through the days. 

It is sat on an insulating matting base and has the additional all over thermal cover fitted when not in use.

With 30 minutes use, including running the air jets for some of the time, the temperature then drops by another deg or two, but still acceptable. I think the air jets accelerate the heat loss though as you end up blowing lots of ambient temperature air through the water.

The heater is scheduled to switch on daily for just under 7 hours, coinciding with the off-peak Eco7 timings.

I'm sure if it was used for several hours and left uncovered for an extended period through the day, then the temperature would drop more, perhaps to the point where more heat may be required.

But for our usage pattern, the overnight heating schedule is working well so far.

Get yourself something like this to place on top of the water under the cover. Also really helps retain the heat.

https://www.amazon.co.uk/dp/B01MY2D5BE?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1&th=1

Ignore the price, I paid £28 a few years ago for this, so worth having a look around for something similar and cheaper.

lohr500

powerful_Rogue said:lohr500 said:

Get yourself something like this to place on top of the water under the cover. Also really helps retain the heat.

https://www.amazon.co.uk/dp/B01MY2D5BE?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1&th=1

Ignore the price, I paid £28 a few years ago for this, so worth having a look around for something similar and cheaper.

The hot tub already has an inflatable lid similar to your link fitted into the top cover. And then on top of that I have the thick thermal cover. I wonder if another inflatable disk would make much difference? I guess if I could find one cheap enough then it might be worth trying.

masonic

barker77 said:

dunstonh said:

There is also the option for economy 7.

Is it possible to get economy 7 with a smart meter if never had it before ? Wasn’t sure if needed different wiring etc 

Just to add I have switched between economy 7 and single rate a couple of times now. The change takes a few days to register in the national database, but Octopus will apply an E7 tariff immediately if you want. I'm using the current 12 month E7 fix as an alternative to Agile, given the reduced standing charge. The off-peak times for Go wouldn't suit me (besides me not being eligible).