My apologies to those who PMed me, and who I'm only getting round to now. (edit to add: a ball of my PMs were marked read at some stage, presumably by me, so some of your queries are over a year old-if you did get in touch apologies again, and if you still need info, drop me a line and I'll try not to be *quite* as slow in coming back to you)
My supplier, (it was a self install), has ceased doing domestic work, and are now concentrating on the commercial side of things. As I assume they may still supply the gear, I can't name them here, but I'll PM those who contacted me in the hope that they'll get the same great service I did.
I had a couple of issues down the line, unrelated to the install, or the quality of the equipment supplied, and they could not have been more helpful.
Hello, I don't have solar panels installed in my house yet, but i used to work installing them for a period of about 2 years. Just one thing that should be mentioned when you are considering the payback period for the cost of the install...
If you are installing a new stainless steel cylinder for your old copper one it should last a lifetime and you should never have to replace it again, where as you will probably at some stage need to replace your copper cylinder.
I have worked out the electricity cost for the pump unit if its a good economy one it will cost about 15 euros to run for a year.
One more thing is that while solar panels do primarily heat hot water, because when your heating comes on it has to pass through your domestic cylinder (through another coil) you will notice the heating doesn't take as long to heat up thus saving you a bit more on heating costs.
One more point is that even if it does take 8 years to pay for the system, at least you know after that it will be saving you money for nothing. and the way oil prices are going the cost benefit in the future will most probably be far better.
I'm just at the final stages of a putting in a new heating system in my house. Switched from oil to gas, removed gun barrel etc. I planned to get the solar in at the same time but unfortunately my budget won't allow it. I will be putting in a 250L dual coil cylinder and the plumber will run the provision for the solar. Is it ok to use copper with compression fittings or should he be using the stainless steel flexible piping which is more expensive?
Copper pipes should be fine, although the stainless steel pipe tends to be insulated a lot better as there will be no patching around fittings, but this will be negligible if the copper pipes and fittings have been insulated well.
The only thing is with every compression fitting you are increasing the chance of a leak on the system. Might be an idea making sure that any fittings in the pipework will be accessible.
If it was me doing it i would probably try pay a bit extra and put in the Stainless steel piping.
year of installation, May 2011
m2 area, 6
orientation, south 37 degree angle
flat plate or tubes, flat plate
cylinder size, 300l
summer heat dump strategy ( if any ), no but covered panels while on holidays
self installed. Put in the 300l tank last year as the copper tank developed a leak and thus i got the go ahead from "the boss" to put in action what i had been planning for about a year previous. so i replumbed the house (S??t builder), put in a new condensing boiler, controller and trv's on the rads. only got around to putting in the panels this May as i was getting the roof insulated in march and april (dormer, completely stripped, vapour block and completely sealed to wall plate, rafters built up to 300mm, insulated with glass fibre, etc U value calculated to 0.12). after the roof was being re tiled i went up and installed the panels with the help of the family pullng on ropes etc.
very happy with it! Water heating costs have plumeted.
Does the orientation make a huge difference? My roof faces southeast, rather than due south.
Do these systems just heat washing water, or do they heat radiators as well?
What's the ideal size for a standard three-bed semi?
I'm no expert - just my 2 pence worth.
Watch your roof and see what time the sun hits the roof in the morning and what time it loses it later in the day. However, given the fact that the air temp is lower in the mornings, it would not quite be as efficient as a SW facing roof.
As for sizing, you really need 50 tubes with a 300l store (or I have 30 tubes with 180l). It really heats hot washing water but if oversized on the tubes side, could in theory be used to transfer heat from the store into a rads circuit to take the chill out of a house in late spring or early autumn (via a second coil) - that next on my to do list !!
Likewise I am no expert but this link let's you input all the various data for your location, orientation, roof pitch etc. and calculate the output of a solar PV panel.
By running the calculations for due south and for your actual orientation you can see what drop off you have from the ideal. As it's based on calculating the solar radiation I presume it's also reasonably valid for solar thermal.
FWIW my roof is also facing south east and the passive house planning program calculates that 8m2 of tubes will give me 69% of my yearly estimated DHW demand.
There is a small fall off when you go from S to SE. About 10%, and slightly more than that if the roof is steep. If you have a SE roof with a 30 degree pitch, that is better than a SE roof with a 45 degree pitch.
We have a computer simulator that can give precise figures based on your geographical location, roof orientation and pitch and the type of panel used. PM me if you want that.
Our roof is a standard sort of pitch - it's a typical 1930s semi - but I have no idea what that pitch is. Any tips? If I lean out the skylight and put a spirit level on the roof will it show the percentage pitch?
I really wouldn't worry to much about the pitch of the roof, unless it is at a very shallow or deep pitch it wont make too much difference. As for the roof being not due south, i don't think many roofs are, so there would be a loss of efficiency but what we would have recommended as installers would have been to just add a few extra tubes to compensate if you are using vacum tubes that is.
I'm just wondering what figure to put in that calculator, though.
Unfortunately it's designed for people from another planet than mine. Azimuth? Installed peak PC power? Tracking options? They might as well be speaking Greek.
Firstly as it may not have been obvious, the calculator in the link calculates the amount of electricity generated by a solar photo voltaic panel.
It will not calculate the amount of hot water you will get from a solar thermal panel.
The idea was more that you could see for yourself how much a panel mounted on your roof would produce compared to the ideal south facing orientation.
The Azimuth is the direction in which your roof is facing, so if it is facing directly south you put in 0 and if it is facing due East you put in -90.
So you only need to pick your location off the map and put in a value for the pitch of the roof and for the azimuth and all other values you can leave at the default.
The idea was only to demonstrate to you that it is not the end of the world if you don't have a roof facing due south.
For example my own roof is facing approx. south east (-43) and is at 45 degrees pitch but I lose only 5.2% compared to the optimum for my location which is facing due south with a 37 degree pitch.
@championc What is this 'coil' of which you speak?