Anyone help with a solar thermal panel problem?

[ABCwarrior]

Hi, not sure if this is in the right place but I may have a problem with my panel or Resol controller.
Had the neighbours over yesterday, all in the same style of houses for almost 3 yrs with identical panels on the roof. But on looking at the amount of "solar hours" generated in the last2-3 yrs it turns out they've both got readings of 2300-2400 whereas ours is at 1160? It seems to work ok in the summer, so anyone know why this big difference is showing? Is the panel defective, or the sensor/controller? There's no faults registering on the Resol unit? One neighbour is a t the southern side of the place and has 15-20m pines shading his house(when the snow melts his house is always last to go) so surely his panel should register a lot less hours....

 

[ALEC1]

are the boiler/immersion heaters set up the same?

 

[ABCwarrior]

Not sure what you mean Alec? We have an allegedly "eco" house- this seems to have a 210L "thermal store"- linked into this is a 4m2 solar panel to give hot water when conditions are right, a 12kw Woodwarm multifuel stove which provides hot water when the fire is on, two 3kw immersion elements for getting hot water when there is no heat from the fire and outside conditions don't work the panel properly. So our house presumably gets it's hot water by a cold supply going through the store, and also through the store is a pumped system to provide hot water into the house's 6 radiators in various rooms when the temperature in the store gets over 65c. The Resol thing monitors 4 things as far as I can see from the display- outside temperature at the panel, total "solar hours", and the temperature at the top and bottom of the tank.
But if mine is registering half the solar hours of my neighbours and all seems ok on the Resol display I don't know if there is a fault with the panel, the sensor, the display or what? I've dug out all the stuff and the panel is made by AES Solar up here in Forres (http://www.aessolar.co.uk/) so will give them a call in the new year, but it was all installed by a solar heating and plumbing "specialist", not the manufacturer of the panel, and as our house is 1 1/2 storeys we have no loft where the sensors are meant to go, so this installation firm put an internal spec sensor on the roof outside- one neighbour has had to have his replaced as water got into it and snow/ice had shattered the casing!

Maybe I should start with the manufacturer before calling out anyone to look at it?

 

[dcawkwell]

the controllers usually work on a difference before pumping heat from the panels to the thermal store so if you have the immersion heaters set to provide hot water until 9am and then go out to work it is unlikey the solar panels will get hot enough to ever switch on through the day
so compare your other setings with other neighbours first

 

[ABCwarrior]

We rarely use the immersion heaters at all- only usually in the summer, and all seems to be working ok, it's just this difference in the amount of "solar hours" between ours and the neighbours that is the cause for concern- maybe the panel isn't doing what it should in terms of efficiency and is defective? The panel isn't needed at this time of year anyway. Maybe the thing to do would be wait until early summer, and if there's a forecast of a sunny day then check with the neighbours what their "hours" reading is at the start of the day and at the end, and what temperature their tank is reading (providing I can get them to keep conditions the same- might be difficult to get them not to use their water during the day as they've all got kids!)

 

[Norcon]

Maybe your neighbours don't use the solid fuel as much or don't have it at all. What make is the thermal store?

 

[dcawkwell]

We rarely use the immersion heaters at all- only usually in the summer, and all seems to be working ok, it's just this difference in the amount of "solar hours" between ours and the neighbours that is the cause for concern- maybe the panel isn't doing what it should in terms of efficiency and is defective? The panel isn't needed at this time of year anyway. Maybe the thing to do would be wait until early summer, and if there's a forecast of a sunny day then check with the neighbours what their "hours" reading is at the start of the day and at the end, and what temperature their tank is reading (providing I can get them to keep conditions the same- might be difficult to get them not to use their water during the day as they've all got kids!)

so if you arent using immersion you are using another heat source and obiously this is keeping the store hot so the solar has no reason to switch on.
if the neighbours have kids and they are therefore using more water the solar has a chance to actually kick in. the solar wont come on if there is nothing to heat

 

[ALEC1]

younhave to ensure that the settings are identical on the controller, and that the installations are the same...may be they used more hot water too, keeping the pumping hours up due to a lower temperature at the bottom sensor...do they have bigger families?

 

[Agile]

I think thats likely to be the answer!

With their kids they will use more hot water during the summer when there is enough sunshine to heat more water.

Obvious solution get some kids!

Tony

 

[Dan Robinson]

Goddamitt, that reasoning doesn't work with my missus



Note to self... to get end away, buy solar panels.... has someone told the manufacturers yet?

 

[ABCwarrior]

Cheers for the replies- that may very well be the answer, as I work away quite a lot so maybe am only back 4/5 days a week, the missus works 2 on(48hr) shifts and 4 off, and with an elderly mother 50 miles away when she does come off shift she usually ends up there for 2 of the 4 days off. All houses are identical spec, but 2 of the 4 opted not to have a shower installed so have the bath going constantly I'd assume- they seem to run their fires through the summer too(total waste of wood/coal IMHO, the houses are well insulated and have a fair amount of glass so the windows are opened a lot in summer....I'd just use the solar + immersion, cheaper even and less hassle).

So in a nutshell it's probably ok, and the thermal store will be at a higher than average temperature than theirs more often so therefore the solar won't kick in until we use some hot water, so it's having to do a lot less work so that's why the solar hours reading is much lower?

 

[Agile]

I expect that your "hours" is only the hours when the panels are actually heating the cylinder.

If you have ensured that the cylinder is already hot from burning fuel or an electric immersion heater than the solar cannot help even if its a lovely sunny day!

Tony

 

[ABCwarrior]

Great advice folks- I know that for the central heating to come on 3 of the houses have had the thermostats set to kick in at 65c, but one neighbour has had his set at 85c. Is this too high and likely to cause any damage?
Thing is, when we had that mini hurricane up here we lost power for 26hrs- the installers have had to put in a "gravity" radiator on the upstairs because with the fire on, no electric to work the pump, there is a risk of it probably blowing up as the water in the tank just boils. I heard the tank bubbling away that night, but this "emergency" radiator was stone cold.
Nicest hottest shower I've had yet though....
If I got my thermostat shifted to 85c then surely I would get a much hotter, fuller tank. As it is the central heating is a joke, but I'd rather conserve hot water for showering and other stuff. Right now it kicks in and pumps what hot water has been generated around the radiators ensuring a pish shower most of the time, so all but the one constant radiator in the downstairs bathroom is off- the multifuel stove does do a good job of heating the house so the radiators are a surplus waste of time! In the summer they're not needed, and to run them from immmersions is financial madness....
I'll maybe photo the tank/pump and ask how easy it is to alter the pump kick in temperature.

Cheers again folks!

 

[mointainwalker]

All in all ABC, when I recall the other problems you have had with your house and the energy-saving "bits" , the eco label seems to have been just a marketing exercise and the developer not very conversant with what needed to be done.

Was this just a developer-built scheme or was there any public money/involvement ?

Have you got the other problems sorted out ?

 

[Agile]

Unfortunately, Building Regs and some planning aspects encourage developers to provide eco-homes. Its thought of as a selling point!

The reality is that many of these installations are hastily put together often by people without enough experience. One of them even asks for advice on this forum!

Many of them will work quite well but only when the user fully understands whats involved and plans/adjusts the use to maximise the benefit.

Many of the engineers on this forum have installed their own thermal solar system and find it very beneficial.

Far fewer others are very impressed and many gain little benefit at all. The problem is that personal intervention is often required to ensure hot water is available when required. Late risers benefit most!

Tony