Solar Panels (tank sizing).

topazkk

We are planning to get solar panels installed at the moment and I have a few questions that I'd like to get peoples opinion on if possible. (2 Adults and kids aged 6, 9 and 13 in the house). I am aware of the rule of thumb 50lt/person + 50lt over.

We've been quoted

€3,650 for 300lt triple coil installed. (evacuated tube panels).

and

€4,500 for 400lt

but the installation of the larger tank necessitates moving the hot press location upstairs to an existing walk in hot press (small rad installed) but this in incurring an extra €800 for installation (although this could be less as it a bit of an unknown quantity until pipe runs are determined etc).

My questions are

1. Does anyone feel the larger tank merits the extra expense?

2. Could extra support be necessary to carry this volume (400lt) of water
upstairs?

3. Does this quote seem competitive otherwise?


Thanks in advance.

topazkk

Can anyone offer any advice or thoughts on this we really need to apply for the grant and they are looking for some specific information re number of tubes, area of panels etc.

Thanks, Brendan.

freddyuk

No one can help you as you have not provided very basic information.
You have not stated whether you have baths or showers or both. Power showers? Why triple coil cylinders? What other heat source do you have etc. etc.
Pressurised or open vented?
If you have been quoted for a system then what system is it for? How many collectors and what output?
For that sized family a 250 litre store with appropriate input is plenty so I wonder why you think 400 litre might be necessary. That store will weigh almost half a ton over a small area so unless the floor is strengthened it may be too big but you need someone to check for you.
I would not spend any money until you have been given proper advice and offered a proper design for your needs.
You may then get some opinions here.

ccsolar

topazkk wrote: »

Can anyone offer any advice or thoughts on this we really need to apply for the grant and they are looking for some specific information re number of tubes, area of panels etc.

Thanks, Brendan.

PM Sent

topazkk

freddyuk wrote: »

No one can help you as you have not provided very basic information.
You have not stated whether you have baths or showers or both. Power showers? Why triple coil cylinders? What other heat source do you have etc. etc.
Pressurised or open vented?
If you have been quoted for a system then what system is it for? How many collectors and what output?

Thanks Freddy,

Our reason for a triple coil is that we've got an oil fired heating system and also an open fireplace with a back boiler and the third coil for the proposed solar.

We've got four shower (gravity fed) and a bath but intend fitting a pump to supply these bathrooms on demand.

The system is open vented.

The proposed systems are 4.5m sq for to supply the 400lt
and 3m sq to supply the 300lt.

championc

Hi there

You sound like your system could possibly be undersized but this is based on my own experience. I have a 30 Tube King***n system with a 180L store. In the height of the summer on a completely sunny day last year, the store temperature increased by 30 deg C. Therefore, a 300L store would only have risen by about 15 deg C. So from my experience, I would recommend 50 tubes for 300L and you can work out yourself how many would be needed for 400L in order to get a reasonable return from the system. Anything smaller and I fear you will get little or no heat during days of Winter sunshine and a minimal return from Spring and Autumn


C

homer911

I have 40 tubes facing due south with a 300l tank with 3 teenage kids plus myself and the wife and find this to be about right for our usage.

Usage and roof orientation are most critical in a decision like this and only a professional, with an on-site inspection, can give you a properly sized system