Solar power for shed

New to renewable energy? Have questions? Here's a great place to ask them and view information about wind and solar power basics.

Solar power for shed

Postby colint50 » Sat Jan 14, 2017 11:52 am

Hi all, I am hoping that I can get some guidance and suggestions from those that are more knowledgable on solar than myself. A retired neighbour is wanting to install a small system into his shed. He has a small workshop where he tends to use rechargeable tools and then a large space that his grandchildren use occasionally for weekend stayovers, on a rural property in the Hunter Valley.

He has already purchased 4 x 190w solar panels - specs CEEG model SST SE 190-72M, Pmax 190w, 5.08 Amps, Open cct volts 44.48v, SL open cut current 5.42A
He would require a MPPT, inverter and batteries plus the option of utilising a generator for charging batteries if required in overcast weather periods.

Expected power usage:
1. Small workshop use of rechargeable tools and the occasional use of say an electric saw where a bit of extra grunt is needed
2. General lighting (led's) probably around 6-7 lights -should these be 12v or 240v?
3. Occassion also use of shed by grandkids (late teens or so) - most of the lights would be utilised, say 6 hours overnight, also they have portable car fridges such as Engel, Walcott, etc around 40-60 litres. I haven't been able to find much detail on something like this, however I would expect that they may draw around 2A each, and there could be up to 3 of these units in use.
Maybe it may be beneficial for the neighbour to just buy a bar fridge?

My thinking was to go with 12v lighting, MPPT 20A unit, inverter 1500w, batteries say 4 x 120ah, given that panels total 760W.

I would gratefully appreciate any advice and suggested equipment......thanks in advance
colint50
Solar Fanatic
Solar Fanatic
 
Posts: 30
Joined: Fri Jun 08, 2012 2:25 pm

Re: Solar power for shed

Postby davidg » Sat Jan 14, 2017 9:56 pm

colint50 wrote:He has already purchased 4 x 190w solar panels - specs CEEG model SST SE 190-72M, Pmax 190w, 5.08 Amps, Open cct volts 44.48v, SL open cut current 5.42A
He would require a MPPT, inverter and batteries plus the option of utilising a generator for charging batteries if required in overcast weather periods.

If going 12V then you need to understand that the panels will be 4 in parallel, so will require fusing for each panel preferably in both the positive and the negative leads. Rating MAX 12A the fuses are there so that should a single panel develop an issue (short circuit for instance) and start accepting current rather providing it then the fuse/s will "blow" rather than the panel having a total meltdown (fire).

colint50 wrote:My thinking was to go with 12v lighting, MPPT 20A unit, inverter 1500w, batteries say 4 x 120ah, given that panels total 760W.

A true MPPT charge controller will need to be 60A for 12V with 760Watts of panels and if the panels are set-up properly, under various circumstances it will be able to produce this sort of current. Proper MPPT charge controllers that handle this sort of current are in excess of $300.00 at the very least, elcheapos while they may say they are MPPT they most certainly are not.

A decent inverter preferably a pure sine wave LF (Low Frequency) inverter are by far the best option. Check the efficiency of the unit.

N.B. Pass though or Bypass efficiency or similar is a rubbish spec %, ignore it as the inverter is not actually providing power in that mode, you want the actual inverter efficiency and not the eco mode either.
Hybrid & Off-grid Systems - You could store Sun to use later- I Do!
SELECTRONIC SPMC-482 7.5kW, 7.2kW's of Arrays

with AC-Coupled Grid-Connected Inverters,
1100Ah 48V Bank

Auto Backup Genset
PVOutput Stats

We Sparkys light up your life :)
User avatar
davidg
Solar Crusader
Solar Crusader
 
Posts: 1870
Joined: Sat May 05, 2012 8:38 pm
Location: Dandenong VIC- GRID - Power Retailers are a pain


Return to Q&A - wind and solar power basics

Who is online

Users browsing this forum: No registered users and 3 guests

new solar power specials