MrTWales

Wouldn't I need to do a few things in order to get paid for exporting? Saying that, even the import rates alone would probably make it work out better. Edit - it seems that I just need an MCS cert and smart meter. The later is a bit of a faff given lack of space in the meter box, and the freaking installers haven't given me the certs yet, but it looks like a great option.

Thanks, I need to think about this but when I've looked around I didn't think it was viable to change tarrifs now. I was with Green Planet but when they fell over I got switched to Shell and I certainly don't want to stay with them! All the switch websites say that it's not going to make sense to switch now. What I would like, if possible, is a dual rate where it's cheaper at night as I could charge the battery at night. Octopus used to have amazing rates but they did only offer them (or at least the rates I saw) if you have an electric car. I understood that getting any export payments was not worth jumping through hoops at the moment? I have what I guess is probably a medium sized system, on a flat roof, but it's doing pretty well compared to what I expected. The average generation this month is 17.6Kwh per day so for the summer I'm going to have weeks where I'm exporting a fair bit. You are correct about the battery - it's 3 x 3.6Kwh, so about 9Kwh is useable energy as I have it drawing down to 6%. It's been useful as I don't think I've drawn from the grid this month, other than the small bits that you can't help (which still annoy me!). My average draw from the grid for March was 2.3Kwh and 2.6Kwh for February, which shows how well the battery copes with a good day followed by less sunny days.

I didn't realise how complicated it can be to get the most out of water heating and solar panels. In my case the thermostat tweak, barely half a tick, made a big difference. The water was then too hot to use on it's own (ie without a mixer tap). Maybe next time we have loads of solar I'll use a thermometer to see hot hot is it once it's passed through a tap.

All, thanks for the responses. My conclusion is that, without doing anything fundamental, I can't do much except for setting the thermometer to the max for the immersion (not gas). It was turned almost all the way before, but now it certainly is hotter (it would be too hot without a mixer) and when I turned the immersion on today it stayed on for longer than it ever has before so that's am improvement. It still seems slightly odd that, after a shower at 2pm, the immersion only flicked on briefly many times. I guess the thermoneter is in a place where the water is still hot, and it certainly is! I probably got over 11Kwh into the water today. Also, 28.8 Kwh today - woot!

These are all great points. To be honest, I keep the boiler water heating to a minimum and I even stopped the automatic scheduling. Now, for example, with me on my own (the wife and kids are away) I won't use the gas at all at this time of year and even in winter it would be on for 30 mins in a week if it's just me - otherwise maybe 4 or 5 (at the most) 30 mins heating bursts per week. I get the impression that this is very low useage, but I don't care if the water isn't always hot. Worst case is having to wait 15/20 mins for a shower, but it's usually OK and managable. The tank keeps the water hot for days if it's not used. Having a decent battery helps also as it's usually nowhere near depleted in the morning for this month, so if I know there is sun the next day I've probably got 4-5Kwh spare so I could stick the immersion on in the evening for a hour or so without worrying, provided that we don't have the oven + some other things on at the same time I guess. It would be much simpler with the diverter. I've chased again today! Honestly, all they have to do is install the thing (which I have) and give the warranties and they get the final £1k.

Totally agree. I have a diverter unit that just needs to be installed (the installers ran out of time so will have to come back to install). It's been months but I didn't chase much over the winter as it wouldn't have been used. Though, to be fair, chasing hardly seems to help. I had the immersion turned on for a while today yet still managed to feed in over 9Kwh...sigh.

I've not touched anything and it does seem low. I'll turn it to 55 but I only ever put the gas water heating on for 30 mins max, and not even every day, so it may not make much difference. I'll turn the other know the final bit more to the right!

Damn I really had no idea. I assumed that the water just flowed through a copper pipe in the boiler and this was sent into the tank via a loop!

OMG I just have the turn the dial a bit to the left to help things a bit!

Thanks. The boiler is amazing really, esp when combined with the heat retention of the tank. I doubt we've averaged more than 2.2 hours a week of gas for heating the water, and that's a family of four. But when I'm getting 24Khw from the panels and using 10Kwh I really want to heat up what I can via that method! I undid the box thing and see this. It feels like there are two dials - the red one on the blue bit and the small black one at the top right - and one may be setting the temperature before the immersion cuts out?

Thanks, this does make sense. What I stuggled with is why the immersion stops after about 90 mins max (so 4.5kwh maybe) - unless it just does that even if the temp isn't at the set level (as I'm assuming that the middle being hot would mean that most is).

That box is about 40% up from the floor and has one screw holding it in place. I'm thinking of going for it and unscrewing to see what is behind it - I couldn't kill myself could I? Maybe I can change the temp!

I guess it's that little box thing near the middle? It seems fairly low! I'm even more confused than I was before now.

Thanks, I get that but if it's heating from the bottom and cuts out at, say, 55 degrees then wouldn't it have to heat the whole lot before it stops?

I don't know! There are freaking all sorts of pipes sticking out and I have no idea how the damn thing works. It does seem odd if it's at the bottom though as it doesn't heat that much water, but maybe it is.

My cylinder is called Megaflo cl210. Overall I've been very impressed with how it keeps water hot, but maybe I can improve this aspect somehow with a longer rod. Assuming I ever hear from the effing installers again I'll ask about this when the diverter is fitted.

Yes this is a good point. I can't see this easily and assume I have to unscrew something, but I'll discuss this when the installers finally finish the damn job and fit the diverter. The water does get hot enough, but going from 55 degrees (say) to 60 would help make the hot water last longer.

I get there is no stirring as such, but doesn't the path the water takes with gas effectively cause some swirling? With the electric, it draws 3kw for a while then stops and flicks on only briefly for the day so I assume it's getting the top part to whatever temperature it's set for and then it stops. The gas heats more water in 30 mins (from cold) than the immersion heater does if it's on all day.

I have one waiting to be fitted, but when I switch the immersion on by hand it draws the 3kw for about 60/90 mins but then flicks on and off very briefly for the rest of the day, but the quantity of water heated isn't as much as if gas is used no matter how long it's on for. I guess it just heats the top bit.

Many thanks - re the latter point, this makes sense but I can't control the kids always washing their hair at night etc. It just hacks me right off to give about 10Kwh to the grid in the day but then run out of water water at night! I'll see if I can make sense of the cylinder. I'm still waiting for the diverter to be installed (I'm using the switch manually now) so it may be something I can discuss with the installer as an extra job, esp as immersion heating rods don't cost all that much. I'm generally keen to do what I can myself but this would be way beyond me.

Ah nice. Was the tank always set up like this? My talk isn't that old but I can't imagine it's doing this given how little water is heated.

I've had panels since the winter, and now many days are providing lots of excess energy I'm using some of this to heat the water in the tank. This does work but I'm noticing that the amount of water heated seems far less than when gas is used, even if the immersion heater is switched to on all day. It's OK mostly, but very noticeable if a couple of people have showers. I'm assuming that this is because the gas heating involves passing water through the boiler so you get water swirling around a bit, whereas the immersion heater just heats water at the top of the tank and not below the depth of the heating rod goes. My question is, is there anything anything I can do to heat more water in the day (when I'm passing loads back to the grid for nothing)? I can't think of any way to get the water swirling around, so that only leaves the length of the heating rod? I've got no idea how long my rod is (ahem) but I'm guessing that it's not super long.

Thanks, not sure I understand all that data but it is interesting. Looking at some meter readings I took, there have certainly been days when it's been 0.1Kwh per day (in fact 0.35Kwh over a 5 day period at one point). It's hard to know how much has, in theory, not been needed and is just down to how the systems work for any long periods but I'll have more idea going forward as solar + battery should cover the usage for long periods now and so far this month the battery has never been depleted, with lots more sun predicted over the next week. Maybe today was especially bad. Someone mentioned before than induction hobs can cause some import and I did use that rather then the gas hobs.

Thanks, I'll look through it.

Thanks. I hoped that there was something I could do, but at least I know so I'll stop fretting!