6 hours ago, maxomill said:

also I see  no lighting mentioned,

The fish only read during the day

On 11/22/2017 at 5:35 PM, Clement said:

The owner would like to go complete off grid

The client uses 100kWh a day requiring 20kWp to be "virtually off grid" - if you want a system to reduce the bill a bit then just about anything will do that to some degree. If the grid is reliable, the fish not too fussy and authorities not too difficult then a grid tie system of whatever size you like and gennie backup is the way to go.

7 hours ago, maxomill said:

im curious here

I have one inverter 4kw which can run my house and my pool pump off solar during the day . what about have a single inverter ,say for argument sake a  four 3kw inverters  running  each of the four  items since they are all single phase and  again four battery banks  since they may be spread out over a large area. or maybe two 5 kw inverters running 2 items and two battery banks . they should be able to handle the start up currents  but maybe not start them up at exactly the same time . this also allows for  breakdowns  and if you lose an inverter you don't have to shut down every thing , so get an extra spare inverter and swop it if you do have a problem. to me this covers most bases

wouldn't this also make the battery banks easier to maintain / handle  as nobody really likes to parallel to much.?

 also I see  no lighting mentioned,  just saying

you could run off solar during the day and power  at night  and so still have savings like the grid tie so at the end of the day you are saving

just another quick thought  . the axpert V series has a self consumption mode  and a grid tie feature

cheers

Thanks for that. Makes alot of sense and coming to lighting, the shelters 're made of transparent plastic material and it's not a priority at the moment since work is mostly done during day time

grid tie is fantastic but off grid makes it more complex

I once bred a batch of bass and  a light just above  the water would attract insects  which a lot of would land up in the water . the fish were there having a feeding frenzy .

a bug zapper was also added  there and the fish loved the cooked food as well

point is it saved a lot on feed costs

cheers

 

On 23 November 2017 at 5:11 PM, pilotfish said:

In Joburg where I live you will get 42c for feed in, and charged Time Of Use rates for consumption. Based on the 8hr/14hr split, of your 14hr consumption period you would be charged 302c for 3hour, 125c for 3 hr, and 90c for 8 hr.

@pilotfish Is Eskom now allowing customers to feed into the grid? Or is it City Power who is allowing it?

I used info in City Power documents for the above response, I don't think Eskom smiles on grid-tie

On 11/22/2017 at 11:08 PM, pilotfish said:

4.1kW x 24hr = 98.4kWh per day (ouch!), call it 100kWh so you will need about 20kWp array. So a real cheapo solution would be as follows;

• 6x Axpert MKS 5k in parallel (for the panel capacity, not for the output power which will be way overkill),
  • about R60k
• Each Axpert with 10x 315Wp panels = 3.15kWp x6 = 18.9kWp (not quite 20kWp but close enough),
  • about R150k
• Assume 8hr solar day and 14hr solar night, so your battery bank must carry you for about 14hr's on average.
• 4.1kW x 14h = 57.4kWh supplied by battery, if you use lead acid and limit it to 50% drain you will need 120kWh battery bank.
• 120kWh / 48v = 2500Ah battery bank,
• Ritar make a 2v 1500Ah battery for R4000 - you will need 48 of these for a 3000Ah bank
  • about R192k

That's about R402k, plus R48k for installation sundries and R50k for me that's about R500k - sounds like a bargain!

Note that this wouldn't be Off-Grid but Grid-Assisted (not grid-tie, you wont be feeding any power back anywhere) so that the Axperts can take power from the grid when needed. You will get probably 80% of your power requirement from the PV system with the grid helping out with the other 20% on them dark and dingy days.

If it was me I would want to save R10k a month on the utility bill to make capex worthwhile - I reckon you will save 2500kWh per month so your power cost must be R4/kWh or higher to give this system the green light - if not then just pay the utility bill.

Sounds like a blast, have fun

 

8 hours decent sunshine is a bit over-optimistic. Rather work on 5-6 hours.

Thanks alot for the feedback and recommendations. I appreciate.