micro tie inverter

kbhale · 04-21-10, 01:41 AM

I hope to have enough panels for a 300 watt micro-tie inverter. I pay $0.13 per KWH. If I am able to pump 4 hours of, lets say 250 watts in to the grid per day it would come to 250w x 4 = 1kwh. Which would equal $0.13. A 30 day month at 1kwh per day price, $0.13 x 30= $3.90. Year $0.13 x 365= $47.00.

Am I calculating this right?

The micro tie inverter is $95.00 on ebay. It would take 2 years to recover the investment but it would be 365 KWH per year that I'll not need to buy from a coal fired grid.

I known I can pump more Wattage. I just want to be sure my thinking on the math is right.

kbhale · 04-22-10, 01:14 AM

open voltage. Most of the micro inverters say they need at least 14 volts to work.

I turned my old garage into a green house than BBQ kitchen. Now use solar water for hot water. So i'm going to use this hot water heater with a 12 volt 600 watt element as a energy dump.

My combiner finished.

This is Nuisance the cat. He is sitting on the 600 gallon hot water storage and in front of the storage batteries.

I've been buying the harbor freight panels as they go on sell. They are 45 watt per set at 12 volt. I'm wiring them so, each set has it's own 5 amp glass fuse.

It's 83 feet from panels to batteries. Have 6 sets now 270 watts. Plan to have 8 panels at 360 watts. 360w / 12v = 30 amps. Unlike AC. DC loses a lot of energy over distance. I required 0 AWG a wire as big around as your little finger to carry the power.

All the panels are facing south. Might have been better if they faced South South West.

I am trying to keep things to code. At least looking like code.

This is a great site to learn the basics.
http://www.freesunpower.com/index.php

Xringer · 04-22-10, 12:29 PM

Wow, I just looked at those panels. - Harbor Freight Tools - Quality Tools at the Lowest Prices

Before shipping, they cost $5.55 a watt. That seems a bit high to me.
If you plan to add more PV, you might want to look at some of these.
155w solar panel, solar module 155w or, 120w solar panel, solar module 120w
Minimum order is 2 for the 120w and 4 for the 155w.

I've been watching those little 300w grid tie solar panel power inverter DC28-55v to AC
on Ebay, since they use higher voltage, I could put some panels in series, run higher voltage (& less current),
which would allow the use of smaller (cheaper) cables.

Anyway, they are manufacturing new models of mini-inverters
every month it seems. I've seen new models with LCD displays
and some that output 220vac, and a larger range of power handling.

If you look at the EnPhase idea of 1 inverter per panel, you can see
how power-point-tracking can really help out your harvest.
So, IMHO this is a good reason to buy inverters to match your panel
or panel pairs..

kbhale · 04-22-10, 10:16 PM

I buy them out of pocket when they are on sell or have coupons. The most I’ve paid for a set is $160.00, $3.55 a watt. The store is 5 minutes from my house. For now I’m just getting two more sets. Which will max out my 30 amp charge controller.

Plan to buy a 3k-5k pallet of thin film next year. I decided to go solar water / heat and insulation this year.

Until I get all the solar heat up and going I’m not using a lot of the energy the pv panels are turning out. A micro inverter could make the extra energy useful. A LED read out and counter would be great.

What I really need to do is make a decision on what voltage to use 12vdc or 24vdc so I can get a proper charge controller and inverter system setup.

04-21-10, 01:41 AM	#1
kbhale Helper EcoRenovator Join Date: Jan 2010 Location: Evansville IN Posts: 88 Thanks: 0 Thanked 1 Time in 1 Post	micro tie inverter I hope to have enough panels for a 300 watt micro-tie inverter. I pay $0.13 per KWH. If I am able to pump 4 hours of, lets say 250 watts in to the grid per day it would come to 250w x 4 = 1kwh. Which would equal $0.13. A 30 day month at 1kwh per day price, $0.13 x 30= $3.90. Year $0.13 x 365= $47.00. Am I calculating this right? The micro tie inverter is $95.00 on ebay. It would take 2 years to recover the investment but it would be 365 KWH per year that I'll not need to buy from a coal fired grid. I known I can pump more Wattage. I just want to be sure my thinking on the math is right.

04-22-10, 01:14 AM	#2
kbhale Helper EcoRenovator Join Date: Jan 2010 Location: Evansville IN Posts: 88 Thanks: 0 Thanked 1 Time in 1 Post	open voltage. Most of the micro inverters say they need at least 14 volts to work. I turned my old garage into a green house than BBQ kitchen. Now use solar water for hot water. So i'm going to use this hot water heater with a 12 volt 600 watt element as a energy dump. My combiner finished. This is Nuisance the cat. He is sitting on the 600 gallon hot water storage and in front of the storage batteries. I've been buying the harbor freight panels as they go on sell. They are 45 watt per set at 12 volt. I'm wiring them so, each set has it's own 5 amp glass fuse. It's 83 feet from panels to batteries. Have 6 sets now 270 watts. Plan to have 8 panels at 360 watts. 360w / 12v = 30 amps. Unlike AC. DC loses a lot of energy over distance. I required 0 AWG a wire as big around as your little finger to carry the power. All the panels are facing south. Might have been better if they faced South South West. I am trying to keep things to code. At least looking like code. This is a great site to learn the basics. http://www.freesunpower.com/index.php Last edited by kbhale; 04-22-10 at 01:27 AM..

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04-22-10, 12:29 PM	#3
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Wow, I just looked at those panels. - Harbor Freight Tools - Quality Tools at the Lowest Prices Before shipping, they cost $5.55 a watt. That seems a bit high to me. If you plan to add more PV, you might want to look at some of these. 155w solar panel, solar module 155w or, 120w solar panel, solar module 120w Minimum order is 2 for the 120w and 4 for the 155w. I've been watching those little 300w grid tie solar panel power inverter DC28-55v to AC on Ebay, since they use higher voltage, I could put some panels in series, run higher voltage (& less current), which would allow the use of smaller (cheaper) cables. Anyway, they are manufacturing new models of mini-inverters every month it seems. I've seen new models with LCD displays and some that output 220vac, and a larger range of power handling. If you look at the EnPhase idea of 1 inverter per panel, you can see how power-point-tracking can really help out your harvest. So, IMHO this is a good reason to buy inverters to match your panel or panel pairs..

04-22-10, 10:16 PM	#4
kbhale Helper EcoRenovator Join Date: Jan 2010 Location: Evansville IN Posts: 88 Thanks: 0 Thanked 1 Time in 1 Post	I buy them out of pocket when they are on sell or have coupons. The most I’ve paid for a set is $160.00, $3.55 a watt. The store is 5 minutes from my house. For now I’m just getting two more sets. Which will max out my 30 amp charge controller. Plan to buy a 3k-5k pallet of thin film next year. I decided to go solar water / heat and insulation this year. Until I get all the solar heat up and going I’m not using a lot of the energy the pv panels are turning out. A micro inverter could make the extra energy useful. A LED read out and counter would be great. What I really need to do is make a decision on what voltage to use 12vdc or 24vdc so I can get a proper charge controller and inverter system setup.