Saving energy and close to £1k per year with a hot water bottle

toby3210

I stumbled across this piece of research that showed that switching your thermostat down by 1 or 2 degrees (not off completely) and using a hot water bottle instead can save you close to £1k per year if you live in a detached house. 

I'm contemplating it as an experiment but would be great to hear how easy it was to do. Has anyone tried this and succeeded?

EssexHebridean

The higher saving is presumably assuming someone is heating that  (fairly large!) detached house with direct electric heating at standard rates - which mercifully, not too many people have to do. The gas saving is a bit more modest, to say the least, whether it takes into account the cost of filling the hot water bottle repeatedly through the day is another question! 

It’s well know that a good saving can be made by turning the thermostat down a degree and sticking an extra layer on - this is a slightly faffier version  of that. Good marketing by a hot water company though! 

Alnat1

I'd go with the heated throw rather than a hot water bottle.

QrizB

toby3210 said:

I stumbled across this piece of research that showed that switching your thermostat down by 1 or 2 degrees (not off completely) and using a hot water bottle instead can save you close to £1k per year if you live in a detached house. 

The article is on a website belonging to "The Hotel Water Bottle Shop" which could take your first clue that it's not quite what it seems! It's making some quite sweeping assumptions.

FreeBear

According to the Energy Saving Trust*, turning your thermostat down by 1°C can save 10% in energy costs - I need to call BS on this. Actual saving is more likely to be 3-5%, but still worth doing.

As for using a hot water bottle - I'd rather use an electric underblanket. The one I'm currently using consumes 10W on a low setting and has a timer to automatically switch off. If I need extra warmth under the duvet, I have a cat

*) https://energysavingtrust.org.uk/new-research-finds-96-of-uk-homeowners-are-concerned-about-their-home-energy-efficiency-yet-one-in-five-arent-taking-simple-steps-to-improve-it/

brewerdave

In a 5 bedroom detached my total gas bill for the year is £1k including cooking, hot water and heating - so a hot water bottle is going to replace all of that expenditure LOL

Scot_39

Alnat1 said:

I'd go with the heated throw rather than a hot water bottle.

Or a couple of cheap £10-12 per set pair of thermals - 1 set on one in wash etc -  work in all rooms as move around, easier for wfh at desk etc etc.

born_again

Sorry, but don't fancy walking around with a hot water bottle strapped to me. But what about the rest of the people in the house?
More people = more electric used to boil the water, so less savings. 

Think I'll pass on their offerings £17.99 to £99.99 😶‍🌫️🤣 Which nearly wipes out any savings...

Scot_39

The costs vs benefit will change for almost every scenario.

Like my suggestion above re thermals - its easy to save the £24 for one - especially with electric heating - by cutting rooms a couple of degrees.

But buying for say a family of 4 - thats near £100 - and for a home with gas at a half to third of average e7/e10 price /kWh for a moderate electric off peak user - a lot less clear.

And then would you need them anyway - as then say four folk in a room - gives more than just one's body energy release - and over several hours - thats not trivial energy / heat output - cf many rooms losses.

bob2302

FreeBear said:

According to the Energy Saving Trust*, turning your thermostat down by 1°C can save 10% in energy costs - I need to call BS on this. Actual saving is more likely to be 3-5%, but still worth doing.

3-5% seems a too low to me - although it might might be right for air source heat pumps because they are least efficient in the cold weather.

If you model losses as being, to a first approximation, proportional to T-T0, T0 isn't the outside temperature, it's a linear combination of the outside temperature. a suitably defined underground temperature, and if not detached, your neighbours'  room temperatures.  This makes 10% feasible imo.

victor2

My CH is off at night, so how would a hot water bottle save against that?