Solar Thermal Install

[armalites]

I assume you already know this but just in case, you need to make sure the system is all in place filled and functioning before you put the tubes in the manifold.

Something you can do to avoid dumping(you still need to have it in place) is to run the system at a higher temperature and fit a blend valve to lower the temperature of the hot water.

I was chatting to a guy at the place I got my kit from and he ran his cylinder at 85 degrees and even when he went on holiday in the middle of summer with nobody using the hot water the stats showed it never dumped heat once. The other benefit is your tank of water has more capacity.

 

[Gareth J]

Just to recap, these are the bits I picked up free:

This:

View attachment 337274

This:

View attachment 337275

This inverter:

View attachment 337276

View attachment 337277

3 of these batteries:

View attachment 337273

View attachment 337272

No idea what to do with it but think I need some PV panels.

Good haul!

The sma is a decent brand. I think it can be used to tie the batteries and grid together but you'd need to check the manual. The victron should, judging by the blurb on the front. Either way, you should probably check they work unless you know they do. Wiring is very simple, mains in one side, DC, (probably via mc4 connectors) the other. You'd need a DC supply capable of exceeding the inverters cut in voltage (again, in the manual) but your batteries might be able to do that.

In all honesty though, 1500W is a bit on the low side. Unless you only have a very small roof space. https://base.k2-systems.com/ do a useful system calculator that lets you populate your roof with an imagined setup so you can test how many panels will fit in the physical space and what kW that equals. The DNO will let you fit a 3.68kW inverter and you can oversupply inverters...4kW of panels is usual.

For interest, just pricing a new but budget tin roof mount system. Is coming in at ~£1600+vat for 4kWp and a 3kW inverter including brackets and wire.

 

[Onoff]

Been up 8 years now

View attachment 335364View attachment 335365

Are they stainless rails?

Just the 10 tubes?

 

[Trevorleach]

Are they stainless rails?

Just the 10 tubes?

I literally cannot remember what I did yesterday never mind eight years ago!
I did think of more tubes but after reading about dumping excess heat I settled on the smaller set up

 

[gaz1]

this one 20 years old

I wouldnt build mine this way

extra info

 

[Gareth J]

Too late to edit but my info above is out of date, up to around 5kw of panels on a 3.68kw inverter is now common.

 

[DAPPH]

Large, detached, uninsulated house...

Buy your own second / third hand drilling rig ( EX British army sales ?) and put nine 600 mm dia 90 mtr bores down , slip the alkathene pipes inside re bar cages & cable tie them to the bar ,weld the vertical steel joins as the cages go down and slip the cages down the holes . cap the top two mtrs with rain channel pipe and back fill with sand or a weak concrete mix . Ground heat will still be easily extracted through the concrete a it will always be moist & at 10 oC or so

The guy on TV who did this spent a lot of money hiring the people & plant in to do it .. buying then selling on a drilling rig once you've used it seems the cheapest way to go .
The stubs of protective pipe surrounding the rebar cage tops were all disc cut so the alkathene pipes could be brought out , insulated & run to a common point for the heat exchanger gear . The rest of his house floor was cast around & over everything after a really thick insulation layer was put down . IIRC his first yearly heating bill was around £9 a month for the electricity .

 

[Onoff]

In all honesty though, 1500W is a bit on the low side.

Sorry, what's that in reference to?

 

[Onoff]

Just putting it out there as I'm trying to get my head round where I am with it all.

The oil boiler is currently sat in the otherwise unheated utility. 4" block ling outer wall with a couple of large, single glazed windows, one DG window and a double glazed door. Seems mad to be pumping heat into that space where we're not living.

The orange circle is the position of the HW cylinder that sits in the insulated loft space under the above pictured, SW facing hip.

SWMBO has a hankering for a pantry and we've discussed bringing he kitchen forward into what is currently covered external space where the hot tub is at the mo. Plan was to build a stud wall where the blue lines are.

A thought here to, instead of a pantry make a mini plant room. Move the HW cylinder there plus any solar tank. That along with a UFH manifold.

I suppose the first thing would be to move the kitchen "out" to line up with the lounge wall and end up with a functional "mini" kitchen whilst I gut/dig down the original.

A slight bug in this plan is the kitchen floor is 100mm higher than the nominal floor level in the rest of the house. It all needs digging up and reinstating with a good chunk of insulation underneath and UFH.

?

The losses here must be incredible. Sitting in the lounge with the 2kW fan heater on AND the 2kW oil filled rad. Still bloody freezing! Slowly getting warm.

 

[Gareth J]

Sorry, what's that in reference to?

The "pAC" written on the back of the sunny boy. I think it (1550W) refers to the rated power of the thing

 

[Onoff]

The "pAC" written on the back of the sunny boy. I think it (1550W) refers to the rated power of the thing

So I can only have 1550W of panels connected to it?

 

[Gareth J]

So I can only have 1550W of panels connected to it?

Download the manual. It'll be more than that, probably ~2-2.5kW. but it won't output much over 1.55kW. you can have more than the rated power of panels - how much more depends on the manufacturers spec. If that makes sense

 

[Onoff]

Download the manual. It'll be more than that, probably ~2-2.5kW. but it won't output much over 1.55kW. you can have more than the rated power of panels - how much more depends on the manufacturers spec. If that makes sense

Thanks, tbh I'm so new to all this (and a slow learner ) my head hurts.

I wonder if it would be a smart thing to put a PV install on the SW facing garage roof as this needs re-felting too? Garage is in the left.

 

[Gareth J]

Thanks, tbh I'm so new to all this (and a slow learner ) my head hurts.

I wonder if it would be a smart thing to put a PV install on the SW facing garage roof as this needs re-felting too? Garage is in the left.

View attachment 337521

Nothing wrong with that, it'll bias production towards the afternoon, which can be a bonus if it's a useful time of day or if your local conditions mean it's often cloudyin the morning. But total production won't be so high as due south. Could be a good option combined with, in future, a second array on the SE side if the house. Shading though? Those trees look ominous. Once you have a good idea of potential size of array, (the k2 base tool I linked to can help there), there's a useful estimation tool at pvgis; https://re.jrc.ec.europa.eu/pvg_tools/en/
Will help gauge potential output.

Other things to consider with using the garage; power supply? Is it big enough? Considering the relatively small roof size and the fact this is a welding forum, I'd hazard a guess that the supply cable will not be a limiting factor, but do check!

 

[Onoff]

Am I dreaming or is their a building reg (or similar) that says if you re-roof more than 25% of the roof area you then have to upgrade the whole roof in terms of insulation?

 

[Onoff]

Other things to consider with using the garage; power supply? Is it big enough? Considering the relatively small roof size and the fact this is a welding forum, I'd hazard a guess that the supply cable will not be a limiting factor, but do check!

I've been mulling tray mounts atop the dormer.

Running a new supply is on the cards sometime anyway. Currently bodged overhead it's great for the squirrels to access the roof! Plan is underground.

 

[Gareth J]

I've been mulling tray mounts atop the dormer.

Running a new supply is on the cards sometime anyway. Currently bodged overhead it's great for the squirrels to access the roof! Plan is underground.

A fair bit can be saved by doing a DIY install. If that means buying some more expensive mounts, it still might be worth it.

I've an account with the K2 program, anyone can register but if you want me to roughly mock up a set to check if the sunny boy inverter is appropriate for the garage hip, I will if I get time. Pm me your postcode, the pitch and dimensions of the roof. Don't get too hung up on the sunny boy though, a new SMA of that size is about £400+vat. A Chinese one, ~£250. Worth using if you can but not worry comprising the amount of panels you can fit IMO.

I've no knowledge about tiled roofs, some look easier than others.

 

[Roger440]

Am I dreaming or is their a building reg (or similar) that says if you re-roof more than 25% of the roof area you then have to upgrade the whole roof in terms of insulation?

I think so. Just ignore. Whos going to know?

 

[Trevorleach]

150 litre tank, bottom of it is 54degc heated by solar, and top is at 66degc heated by boiler.

 

[Onoff]

On a bit of a side mission at the mo. I want to hit the button and buy a PV set up to go on the SW facing garage roof. @johnser has kindly been talking to me about it.

I was looking at in roof panels.

I've been told "You need to allow perimeters for trays / apron course at the footer and a gap at the top for wind sheer. For MCS anyhoo".

Clearly if the garage didn't have a hip and was a gable end it would be better for ease of layout.

I'm really not sure what to do.