DIY: Small Solar setup recommendation

arup

arup

Explorer
I want to cut down some electricity costs by installing a solar setup as my following plan, please recommend me if something is terrible and needs to be rectified. I wish to run all house lightings off solar power. I'm not much interested in the PM solar scheme which connects my solar to grid , and want to have a diy setup.

Panel - Luminous 12V 105W - Rs. 4500/-
Charge Controller - Luminous 12V 20A PWM - Rs. 750/-
Considering solar energy harvested daily 800/900watts, I chose battery as,
Battery 12V 80Ah Exide- Rs. 7000/-
For the DC to AC inverter part, I'd like to utilize an Foxin 600va UPS I have lying (with battery dead).

As per my idea, I have to increase the heatsink or add a 12v fan at the heatsinks of the mosfets of the UPS circuit because those would be hot after prolonged use.

This solar supply line will be fed into my house's all lights. Since all lights are LED tube/ bulbs those should run fine with UPS output voltages (which may not be sine wave) . I don't want to run FAN/TV or other heavy loads and overload my small solar setup.

This would require me to hire an electrician for connecting solar AC supply to all switch boards and connect the lights' switches to that supply line. This thing I'm not confident to do myself because only god and electricians know which concealed pipe goes to where . :p

Considering 3/4 tubelights , terrace lights, gate lights, kitchen, bathroom lights, etc ,whose combined wattage is around 150W my battery may supply enough power for the evening to night times..

Now I have to make a changeover circuit by using relay for when UPS output drops, the solar supplied AC line would be connected to mains AC line.
 
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Big setup. In theory, it should work.

arup said:
As per my idea, I have to increase the heatsink or add a 12v fan at the heatsinks of the mosfets of the UPS circuit because those would be hot after prolonged use.
Click to expand...
And the transformer also gets hot. Cut a big hole on your UPS and install a 12v/120mm fan from the outside. It should throw the hot air out.

arup said:
I don't want to run FAN/TV or other heavy loads and overload my small solar setup.
Click to expand...
You should be able to run a DC fan in case you got one of them.

arup said:
Now I have to make a changeover circuit by using relay for when UPS output drops, the solar supplied AC line would be connected to mains AC line.
Click to expand...
I didn't understand this part.
 
arup said:
I want to cut down some electricity costs by installing a solar setup as my following plan, please recommend me if something is terrible and needs to be rectified. I wish to run all house lightings off solar power. I'm not much interested in the PM solar scheme which connects my solar to grid , and want to have a diy setup.

Panel - Luminous 12V 105W - Rs. 4500/-
Charge Controller - Luminous 12V 20A PWM - Rs. 750/-
Considering solar energy harvested daily 800/900watts, I chose battery as,
Battery 12V 80Ah Exide- Rs. 7000/-
For the DC to AC inverter part, I'd like to utilize an Foxin 600va UPS I have lying (with battery dead).

As per my idea, I have to increase the heatsink or add a 12v fan at the heatsinks of the mosfets of the UPS circuit because those would be hot after prolonged use.

This solar supply line will be fed into my house's all lights. Since all lights are LED tube/ bulbs those should run fine with UPS output voltages (which may not be sine wave) . I don't want to run FAN/TV or other heavy loads and overload my small solar setup.

This would require me to hire an electrician for connecting solar AC supply to all switch boards and connect the lights' switches to that supply line. This thing I'm not confident to do myself because only god and electricians know which concealed pipe goes to where . :p

Considering 3/4 tubelights , terrace lights, gate lights, kitchen, bathroom lights, etc ,whose combined wattage is around 150W my battery may supply enough power for the evening to night times..

Now I have to make a changeover circuit by using relay for when UPS output drops, the solar supplied AC line would be connected to mains AC line.
Click to expand...
Man, I don't want to disappoint you, but there's a lot of "best case" assumptions in this. In India, you'll likely get ~4.5x WHr energy output daily from a x W panel, depending on your location (I chose Madhya Pradesh)(this figure is from 2 different solar calculators i tried). That cuts down your average output to ~500w at best. Then consider that you're not using a MPPT controller which cuts down your output to ~0.8x (400w at best).

Also consider inefficiencies of lead acid batteries , which are typically rated at 0.05C (20H) discharge rate. For your case that's ~4A, or 48w. If you go above this rate, the runtime reduces non linearly (8A (2x) might not run for 10 hours, but 9 (<0.5x)).

I'm not saying you shouldn't build the system, or that it won't meet your use case, but rather keep expectations in check.

Good luck with the build :) and do keep us updated.
 
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