diy solar

diy solar

Solar Advice

JMMART

New Member
Joined
May 25, 2020
Messages
1
I have acquired 12 used solar panels (Sova Solar, model # SS280P-72, The panel info tag states, max power 280, open circuit voltage 44.4, voltage at pmax 36.7 and current at pmax 7.78) all panels work. I have also acquired Delta H6 6000w Grid Tied Inverter. I have 100 ft of solar copper wire, 5 pair 4 to 1 Y cables, 2 pair 2 to 1 Y cables, and solar crimping tool and mc4 end connectors.

My electric bill is 600-700 a month, all i am trying to do is lower my bill by half for now. So, I am building a 35X10 patio that will hold 15 of these panels. The questions I have are:
1. What else do I need to hook this up?
2. How do I hook up the panels in a series or parallel?
3. I have a 220v line for a Hot Tub i removed with a 50amp breaker to tie into. Can I tied into the grid there?

Thanks in advance for any assistance you guys can give me.
 
1. What else do I need to hook this up?
I assume you have racking and parts for that.
2. How do I hook up the panels in a series or parallel?
Every inverter is different. Usually there is a string sizing tool on their website. Mine were all in series so I did not need any Y cables. YMMV
3. I have a 220v line for a Hot Tub i removed with a 50amp breaker to tie into. Can I tied into the grid there?
That should get the inverter power into your breaker panel. You will need labels and permission from your power provider to actually feed into the grid. Do you have that yet?
There may also be a requirment for an AC disconnect that you could put where the Air Conditioner pull out disconnect was. Usually they want one with a handle but your permit will probably specify that.
 
this qty of panels should output around 25KWh per full sun day.

$600 power bill, how many KWh is that a day?

in my area, that would be around 220KWh per day, so, 25KWh isn’t going to cut the bill in half...
 
  • Like
Reactions: Eri
3. I have a 220v line for a Hot Tub i removed with a 50amp breaker to tie into. Can I tied into the grid there?

Thanks in advance for any assistance you guys can give me.

Code allows you to have main breaker plus back-fed PV breaker no more than 120% of panel busbar rating, and then only if at opposite ends of the busbar. If your busbar and main breaker are 200A, only 40A PV breaker is allowed. I have 225A busbar and 200A main so 70A PV is allowed. I think a 40A breaker will be sufficient for 6 kW inverter, but check the specs. Breaker should be 25% higher rating than max AC current. At 240 VAC the inverter will be nominally 25A, but would be higher current at minimum voltage.

If your breaker panel has the main in the middle rather than one end, you probably aren't allowed to connect any PV at all because the busbar could end up carrying the sum of main and PV, in excess of its rating. In that case, see if the utility offers a meter-side tap to feed a separate PV panel.

When you go grid-tie PV you (if you are a Californian) are now required to use a time-of-use rate plan. Depending on what hours you draw power (e.g. for air conditioning in the afternoon), the utility may say, "Thank you for giving us power, now here is your increased bill; pay us more dollars." Check your state codes as your mileage may vary.

Some older inverters won't be permitted to connect, but looks like yours is "Rule 21" compliant and has the other features now required for rooftop.

Because you are putting yours on a patio roof I don't think you need module-level shutdown (which is supported by your inverter). If it was on the house roof you would require an extra box per panel.
 
Back
Top