Hello all !
I need your help validating my calculation before I press the "buy all the stuff" button
I'll try to keep it concise :
Two years ago I moved my workshop to an old stone building next to my house. Between my activity (bike frame building) and arranging my workshop on the spare time, I'm finally at the point where I can assemble all the solar parts an heating parts.
The plan is to push solar heated water through my concrete floor and that would be what drives my calculation. In a later part I'll use the excess energy to directly power part of my business activity adding batteries to the mix (hence my presence here).
One thing I was sure as I started this project two year ago, is the use of Dacians geniuosisty (yes that term probably does not exist) so I bought an SBMSO.
So, here are my calculations. Please correct me if I'm wrong :
Note I consider ideal situations of solar conditions and elements efficiency. The plan is a first order of approximation (...) calculations so I can start somewhere.
The Workshop :
Volume to heat : 260m3 (105m2 x 2,5m)
Building Energy loss : 1,2W/(m3.K) (for a "not bad" isolated workshop)
Temp Delta : 15°C (its a workshop...)
Total energy loss :
260x1,2x15 = 4,6kW.
Lets consider that I need 5kW of continuous power to maintain a delta of 15°C in my 260m3 workshop.
Considering I will only be able to gather solar energy for 4 hours / day, I will have to store 24/4x5= 30kW in my water tanks during that 4 hours.
So 7,5kWh power to generate with solar and dissipated as heat in my water tanks.Resistive Elements :
By using 36V 1200W resistive elements, I will need 6,25 of them. Lets take 6.Solar panels :
On the solar side, I plan to buy "330W" 60 cells pannels. To reach the 7,5kWh power I would need 22 of them.Water tank :
Now for the water reserve : Hot would be at 38°C (heating floor entry) and cold would be 28° (heating floor return), so 10° delta (maybe a bit much for the concrete also considering this would be an average). And I need 30kW in that.
Mass of water needed = 2600 l (Liter). I will take 3 x 1m3 water tanks.
All of this is not my field of expertise and I except I could be completely wrong in my calculations. This is why I'm here... :-)
Does it all make sense ? Is it coherent ?
Last note : To start, I only plan to buy 12 panels, 3 resistive elements and 1m3 water tank and keep my stove for this winter ^^
Thank you all for the time you took to read me.