Choice of intelligent switches ?

Cash_Cow_2

I think I'm settling on a Solar iBoost since it has a wireless CT clamp. Put the switch in the living room fed from an existing 13a socket; feed storage heater from unit via a fused outlet. Total DIY and all for £275.:j

Martyn1981

Cash_Cow wrote: »

I think I'm settling on a Solar iBoost since it has a wireless CT clamp. Put the switch in the living room fed from an existing 13a socket; feed storage heater from unit via a fused outlet. Total DIY and all for £275.:j

Sorry to be a bit negative, but I'd have thought diversionary switches like these only really make sense if you can divert summer (for simplicity - BST) generation. The amount of GMT generation you can divert will probably be too small to ever payback the cost.

Remember that spare leccy isn't proportional to generation. Say you generate 20kWhs in the summer (daytime) and use 5, then you have 15 spare. But in the winter if you generate 10 (half), then only 5 (third) spare (and less as gen falls off).

Is it worth it? Could you just use a lower power storage heater and switch it on using MkI eyeball/forecast/luck and any unfortunate import just goes against the £275 saving?

Mart.

John_Pierpoint

So a Solar iBoost only tries to automate what we could do ourselves, were we prepared to sit in front of a divided screen showing generation and current consumption; then flick on/off the immersion/small storage heater when the "spare" generation allows?

Obviously having a 1kW immersion would create opportunities for a 4kWp inverter to heat water during the winter on the days when the sun shines through a cloudless sky?!

In simple terms what does the more expensive technology do? Play with the voltage/send pulses/play about with the sine wave for amps v volts/a mixture of all three techniques (?).
[As a 21 year old in the 1960s, a similar neighbour in a build-it-yourself wooden chalet kit home, lit it with fluorescent tubes and was proud of his ability to pull off some similar trick with his sine phases - I did not really understand then and I still don't now - in those days we called "geeks" DIY radio hams - perhaps he went on to invent something like the wind up radio]. .

orrery

Martyn1981 wrote: »

Is it worth it? Could you just use a lower power storage heater and switch it on using MkI eyeball/forecast/luck and any unfortunate import just goes against the £275 saving?

Tried it and it simply doesn't work. Bearing mind the cost of electricity v gas, the penalty for getting it wrong is roughly 4:1. I tried using a 110v site transformer to give me various heating powers from 100W upwards for maximum flexibility, but immediately you focus on actually doing something (rather than watching the solar monitor) up pops a bank of cloud and you're importing for ages before you notice.

Buy a box to it automatically or forget it, is my advice.

EricMears

orrery wrote: »

Tried it and it simply doesn't work. Bearing mind the cost of electricity v gas, the penalty for getting it wrong is roughly 4:1. I tried using a 110v site transformer to give me various heating powers from 100W upwards for maximum flexibility, but immediately you focus on actually doing something (rather than watching the solar monitor) up pops a bank of cloud and you're importing for ages before you notice.

Buy a box to it automatically or forget it, is my advice.

A Wattson meter is one of the best ways to monitor whether or not it's sunny enough to switch something like that on. If you have one, it's a fairly modest additional cost to add an Optiplug to the installation and automate the process.

Cash_Cow_2

Eric! That was my next post as Martyn does have a point based on this cost. For £150 you can have a hard on/off at a preset level; with an Optiplug connected to a Wattson. All DIY too of course. I guess it could be set low at say 200w and this would be fine with a resistive 2.5kw element load? I also get the bonus of a gadget for monitoring that is always on (unlike my Sunnybeam).

I spend about £60 a month on gas - even if I can only minimise this by a fiver a month that this will paid for in a little over 2 years. Family bonus is maybe a warmer house too?

Cash_Cow_2

orrery wrote: »

Tried it and it simply doesn't work. Bearing mind the cost of electricity v gas, the penalty for getting it wrong is roughly 4:1. I tried using a 110v site transformer to give me various heating powers from 100W upwards for maximum flexibility, but immediately you focus on actually doing something (rather than watching the solar monitor) up pops a bank of cloud and you're importing for ages before you notice.

Buy a box to it automatically or forget it, is my advice.

Agree - left the 800w heater on overnight yesterday! Dohh!

Cash_Cow_2

Sadly I don't think Optiplug will work :-( If its a 1.5Kw resistance it will wait till it has 1.5kw to feed it :-( It 'learns' the load.

EricMears

Cash_Cow wrote: »

Sadly I don't think Optiplug will work :-( If its a 1.5Kw resistance it will wait till it has 1.5kw to feed it :-( It 'learns' the load.

It was really more of a suggestion for orrery who was having problems with a 110V transformer when not being watched. The Optiplug will automate that process but it can't of course offer proportional control.

legoman62

Cash_Cow wrote: »

I spend about £60 a month on gas - even if I can only minimise this by a fiver a month that this will paid for in a little over 2 years. Family bonus is maybe a warmer house too?

I'm using energysavingexp's (from this site) excellent switch idea.....been running it since April 2012 with no problems. Cheap to make, if you are a DIYer and are willing to fit a 1kW immersion heater. I use virtually no gas for the summer months (April - Sept) and less than I would without it, in the winter ones:D