my diy pv set-up - Page 11

jwxr7 · 07-08-09, 08:23 AM

sunday after the sun went down I reseated all the plug connectors for the DC and the one AC plug. The next day things seemed better, it produced a bit over 1200 whrs. I saw readings near peak inverter output too. Then I saw production #s a little above 1400 whrs for yesterday.

Daox · 07-08-09, 12:53 PM

Interesting. Perhaps its time for some dielectric grease.

groar · 07-09-09, 02:27 PM

Quote:

Originally Posted by jwxr7

I'm not sure what you mean by ? Is 11 and 15 the time, like between 11 am and 3 pm?

Yes, I always forget that some people have 2x12 hours per day

Quote:

I remember one day feeling the panels with my hand. They were extremely hot. Aren't the polycrystalline type like mine effected more by temperatue? I also felt the inverter and it wasn't too bad.

All solar panels are sensible to heat. Generally the lower the efficiency and the higher the loss of production because the panel is bigger so it receives more heat. Amorphous, polycrystalline and monocrystalline have different loss coefficient per °C. Mine are at 0.4%/°C. Monocrystalline have a lower coefficient while amorphous have a higher one. Last each panel loose power in time. Mine are guaranteed to have 80% of their initial power after 25 years. Amorphous can loose 20% in the first year then "stabilize" (ie loose "only" a couple % per year next). Best monocrystalline can loose very few power. Don't forget the important temperature is the one of the panels which are rated at 15°C (77°F). At 35°C (95°C) ambient, the panels can be at 75°C (167°C).

In such conditions my panels are loosing 18% : (1-0,4%)^(75-25) = 0.818. Today was rather cool and between clouds was produced a sustained 2.2kW. During last cloud-less day, was produced at most a sustained 1.85kW.

Quote:

The suns path thru the sky is actually quite far north in the morning and evening too. Making me want to angle my array that way slightly, or at least go totally flat. They seem to recommend this for lower lattitudes, but not mine.

Recommendations are generally for a fixed position all year long with a goal of having the max production over all the year, or the max production during the worst months. You may try to turn the panel to East with a low incline so you get a maximum of power when the temperature is lower. From the region, I can see that the systems producing more are those turned a little to the East as they are producing sooner and more in the morning.

Denis.

gascort · 08-04-09, 09:09 PM

regarding the input voltage, according to the Enphase website, http://www.solarpanelstore.com/pdf/E...reliminary.pdf
it says "peak power tracking voltage 22-40V"
Are you still using 12V input into your inverter? Can you put 14-15V into it?
Thanks.b

jwxr7 · 08-06-09, 06:41 AM

Quote:

Originally Posted by gascort

regarding the input voltage, according to the Enphase website, http://www.solarpanelstore.com/pdf/E...reliminary.pdf
it says "peak power tracking voltage 22-40V"
Are you still using 12V input into your inverter? Can you put 14-15V into it?
Thanks.b

I think that m190 may be the latest inverter size they have offered.
My inverter is actually an M200, see page 16 here for input specs. http://www.enphaseenergy.com/downloa...l_20081110.pdf
It does mppt (max peak power tracking) between 44 and 65 volts. My solar array has four 12volt panels wired in series for a nominal voltage of 48v. I guess I may never have described some of that info, sorry.

jwxr7 · 08-06-09, 06:43 AM

I haven't posted july production #s yet, but I remember them averaging about 1kwhr/day. I'll try to get more specific #s soon.

jwxr7 · 09-03-09, 02:37 PM

I had a chance to see my meter run backwards the other day. I was getting ready to go on vacation so I had everything off or unplugged except a few things. When the fridge was running the solar panels (in full sun) would make just enough power to cancel it out. When the fridge stopped running the meter cruised nicely in the other direction

.

MetroMPG · 09-03-09, 02:39 PM

Congrats, Jamie. That's a milestone worth noting.

Daox · 09-03-09, 02:58 PM

Wooohoo, thats really cool.

jwxr7 · 09-04-09, 07:08 AM

Here are some production #s.
For July 30 kwhrs were produced averaging 968 whrs per day. This includes the first week when I was having unusually low production due to a suspected bad connection.

For August 28 kwhrs were made averaging 903 whrs per day. This month had many rainy days that hurt the numbers.

07-08-09, 08:23 AM	#101 (permalink)
jwxr7 Apprentice EcoRenovator Join Date: Dec 2008 Location: mid michigan Posts: 137	sunday after the sun went down I reseated all the plug connectors for the DC and the one AC plug. The next day things seemed better, it produced a bit over 1200 whrs. I saw readings near peak inverter output too. Then I saw production #s a little above 1400 whrs for yesterday. (Support EcoRenovator.org & get rid of these annoying ads!)

09-03-09, 02:39 PM	#108 (permalink)
MetroMPG Infrequent noob Join Date: Aug 2008 Posts: 126	Congrats, Jamie. That's a milestone worth noting. __________________ . To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

09-03-09, 02:58 PM	#109 (permalink)
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 1,232	Wooohoo, thats really cool. __________________ To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

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07-08-09, 12:53 PM	#102 (permalink)
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 1,232	Interesting. Perhaps its time for some dielectric grease.

08-04-09, 09:09 PM	#104 (permalink)
gascort Helper EcoRenovator Join Date: Feb 2009 Location: Saint Louis, MO Posts: 58	regarding the input voltage, according to the Enphase website, http://www.solarpanelstore.com/pdf/E...reliminary.pdf it says "peak power tracking voltage 22-40V" Are you still using 12V input into your inverter? Can you put 14-15V into it? Thanks.b

08-06-09, 06:43 AM	#106 (permalink)
jwxr7 Apprentice EcoRenovator Join Date: Dec 2008 Location: mid michigan Posts: 137	I haven't posted july production #s yet, but I remember them averaging about 1kwhr/day. I'll try to get more specific #s soon.

09-03-09, 02:37 PM	#107 (permalink)
jwxr7 Apprentice EcoRenovator Join Date: Dec 2008 Location: mid michigan Posts: 137	I had a chance to see my meter run backwards the other day. I was getting ready to go on vacation so I had everything off or unplugged except a few things. When the fridge was running the solar panels (in full sun) would make just enough power to cancel it out. When the fridge stopped running the meter cruised nicely in the other direction .

09-04-09, 07:08 AM	#110 (permalink)
jwxr7 Apprentice EcoRenovator Join Date: Dec 2008 Location: mid michigan Posts: 137	Here are some production #s. For July 30 kwhrs were produced averaging 968 whrs per day. This includes the first week when I was having unusually low production due to a suspected bad connection. For August 28 kwhrs were made averaging 903 whrs per day. This month had many rainy days that hurt the numbers.