Old night storage heaters, smart meter and Solar PV battery system

hfj

I am trying to help some friends who have got in a pickle!  They have old night storage heaters but changed their electric setup last year, so they now have a smart meter, solar PV and 4kw battery storage system with Social Energy.  This system stores their solar energy and/or takes advantage of lower priced electric automatically (which is obviously at low peak times).  Social energy say that they are better off than on the old E7 meter.  So now they need to replace the old heaters.  Should they install modern night storage heaters or just standard electric heaters??  (Solar generates only a 5th of their needs and obviously not when they use the most in the winter).  Any help much appreciated.  

Ebe_Scrooge

If they're limited to electricity (i.e. no gas, oil or other alternative), then they need to take advantage of the cheaper-rate tariff.  I'm assuming this is still at night time - that being the case, storage heaters will be their best option.  All electric heating is 100% efficient - the only difference with modern storage heaters over the older ones will be that they're better insulated and more controllable.  So you'll get less heat leaking out overnight, meaning more available for when you want it during the day.

A cheap fan heater/oil-filled or convector radiator could be used to give a quick boost during the day if it's needed, but that'll be relatively costly to run as it'll use peak-rate electricity.  Unless it can run directly off their storage battery - but if it's only 4KWh (I presume that's what you meant when you said 4KW?), then it'll not power a radiator for very long.  And odds on they won't actually need the radiator on when the sun is out and the PV cells are kicking out plenty of juice.

Ectophile

The really important thing to realise is that solar panels generate the most electricity when you least need heating.

In the spring and summer, they can generate loads of power.  With a small battery, I'm pretty much self-sufficient in those months.

Winter is another matter.  The sun's low in the sky, the days are short, and it's often cloudy.  So the electricy they generate is of little use for heating.  For that reason, go for the cheapest form of heating to run - which may well be storage heaters on E7.

Bendy_House

hfj said:

I am trying to help some friends who have got in a pickle!  They have old night storage heaters but changed their electric setup last year, so they now have a smart meter, solar PV and 4kw battery storage system with Social Energy.  This system stores their solar energy and/or takes advantage of lower priced electric automatically (which is obviously at low peak times).  Social energy say that they are better off than on the old E7 meter.  So now they need to replace the old heaters.  Should they install modern night storage heaters or just standard electric heaters??  (Solar generates only a 5th of their needs and obviously not when they use the most in the winter).  Any help much appreciated.  

I think this would need calculating out properly if they wanted to arrive at the definitive answer. This would likely be complex, or at least 'involved'...

It would surely require an idea of their heating requirements over an average year, in kWh. They'd need to know the relative costs of leccy from 'Social' (when at the lowest cost - and when this would occur) compared to E7. And then they'd need to factor in the pros and cons of 'storage' vs 'standard', which I'm sure you know.

My gut says that IF you had enough battery storage capacity to run the heating for a solid majority of days over the year - which, at 4kWh, they surely don't - then 'standard' heaters might be best as they have the advantage of being fully controllable, being used only when actually required. ('Storage' will always charge up, and will always leak heat, whether needed or not. But E7 is cheaper. Modern storage heaters will have better control, and be better insulated, but they are still relatively bulky and have a high initial cost.)

The limiting factor, I think, is the 4kWh battery. This in essence means that it'll provide 4kW of energy for one hour, or 2kW for 2 hours. 2kW will/should keep a living area warm, but that's only for 2 hours once the sun goes down.

I presume your friends know what their current running costs are? (Quite high, I imagine!). 'Social energy' must surely also be able to provide a reasonably accurate estimate of their future costs, assuming 'standard' rads and a 4kW battery? Both sets of figures will be rough and crude, but they should give an indication to allow comparison.

They will also know the cost of E7 leccy? And should be able to find the cost of the cheap rate 'Social' leccy for - hopefully - a direct comparison? They'd also need to know when this cheap rate will be available - is it overnight and during the middle of the day, for example? And, can that cheap rate be used to charge up storage heaters, or will they be limited to just charging the battery?

hfj

 Bendy_House said:

hfj said:

I am trying to help some friends who have got in a pickle!  They have old night storage heaters but changed their electric setup last year, so they now have a smart meter, solar PV and 4kw battery storage system with Social Energy.  This system stores their solar energy and/or takes advantage of lower priced electric automatically (which is obviously at low peak times).  Social energy say that they are better off than on the old E7 meter.  So now they need to replace the old heaters.  Should they install modern night storage heaters or just standard electric heaters??  (Solar generates only a 5th of their needs and obviously not when they use the most in the winter).  Any help much appreciated.  

I think this would need calculating out properly if they wanted to arrive at the definitive answer. This would likely be complex, or at least 'involved'...

It would surely require an idea of their heating requirements over an average year, in kWh. They'd need to know the relative costs of leccy from 'Social' (when at the lowest cost - and when this would occur) compared to E7. And then they'd need to factor in the pros and cons of 'storage' vs 'standard', which I'm sure you know.

Mt gut says that IF you had enough battery storage capacity to run the heating for a solid majority of days over the year - which, at 4kWh, they surely don't - then 'standard' heaters might be best as they have the advantage of being fully controllable, being used only when actually required. ('Storage' will always charge up, and will always leak heat, whether needed or not. But E7 is cheaper. Modern storage heaters will have better control, and be better insulated, but they are still relatively bulky and have a high initial cost.)

The limiting factor, I think, is the 4kWh battery. This in essence means that it'll provide 4kW of energy for one hour, or 2kW for 2 hours. 2kW will/should keep a living area warm, but that's only for 2 hours once the sun goes down.

I presume your friends know what their current running costs are? (Quite high, I imagine!). 'Social energy' much surely be able to provide a reasonably accurate estimate of their future costs, assuming 'standard' rads and a 4kW battery? Both sets of figures will be rough and crude, but they should give an indication to allow comparison.

They will also know the cost of E7 leccy? And should be able to find the cost of the cheap rate 'Social' leccy for - hopefully - a direct comparison? They'd also need to know when this cheap rate will be available - is it overnight and during the middle of the day, for example? And, can that cheap rate be used to charge up storage heaters, or will they be limited to just charging the battery?

Thanks, yes it’s certainly not straight forward.  I’ve got the figures for use over the year and obviously peaks massively in the winter, so won’t get much benefit from the battery then.  Social energy give them rebates for the trading (which they do between 11pm -11am) and for use when prices are lower - so I suspect that storage heaters are still the best option.  I am assuming the suppliers will still be trying to even out the peaks and troughs in demand across the grid - which is why the new green EV tariffs are on offer through the night.  So any tips on which storage heaters are best?!?!?
   

Bendy_House

No idea :-(