my diy pv set-up

[MetroMPG]

Glad to hear you've got that array better anchored.

[jwxr7]

Last night was probably a worst case scenario. The ground was as soft as it usually ever gets, the array is still at the winter angle catching the most wind, and we had wind exceeding 60 mph.

It was still dark when I left this morning, but it looked like it stayed put. I'll look closer when I get home to see if it was pulling at it anchors.

[Daox]

Good to know it didn't move on you!

Also, I'm liking the weekly updates. Its interesting to see the fairly wild fluctuation in power generation. I wonder if in summer if that will tame down?

[Xringer]

Originally Posted by jwxr7

I have a mechanical meter on my house and it will run backward when backfeeding the grid.

We have had a huge warm-up here the last couple days. It was 60f yesterday (we were around -20f only a week ago) so the ground was soft enough for me to screw in a mobile home type anchor to help hold my array in place. It's a good thing too, we Are supposed to get high winds when the cold air moves back in tonight.

Since this seems like only an experiment,(?) I'm wondering if you have the approval of the power company for your connection to their grid?

Trying to work with the power co. is something I don't have much interest in doing.
However, I'm interested in the Enphase Micro-Inverters, but since they are not made for off-grid operation, I'm a bit reluctant to start buying them.

I wonder if one could fool the Enphase units into thinking they were on the grid, by using a 220vac power inverter?? And then use the power on isolated house circuits that require power 24-7.?.

[Xringer]

Originally Posted by jwxr7

Monday, I just finished installing and wiring everything in time to catch sunset on one of the only sunny days we have had . The forecast doesn't look promising anytime soon either. I didn't have my energy monitoring system hooked up yet that day as the sun set, but I did put a current clamp style meter on one of the hot wires and observed a current that was reduced as the sun faded away. So I assume things are working .
Enphase sells an EMU for power production monitoring and stuff, but I cannot justify the cost with my single inverter installation. If I get ahold of more panels and more inverters, then I will probably look into getting an EMU. For now I rigged up a Kill A Watt energy meter to read one side of the 240v ac line that the inverter uses. I should be able to multiply the watt hour readings by 2 to get a good idea of what the system is producing. A note on the Kill A Watt; it reads the current on the neutral line. Trying to do what I am, that is a problem. The 240 system to the inverter doesn't use the neutral for current carrying, just communication. I had to route one of the hot wires thru the Kill A Watt's neutral side and the neutral thru the other. The Kill A Watt doesn't seem to mind, and seems to be reporting current consistant to my clamp on meter.
One drawback of this monitoring set-up is that it doesn't tell me which direction the power is flowing. The Kill A Watt doesn't know the difference. I do know the stand by power used by the inverter though, so I can figure it out.

The way I understand 230VAC is, the neutral line is the return for the two 115VAC lines that make up the 3 wire 230v outlet.




I remember one time when a fuse blew out on a drier. No heat at all, but the motor kept turning. My shirts were getting a ride, but stayed wet..
It was a 115V motor.. It sure seems like that neutral is going to be used to pass current whenever a load is placed between one of the hot sides and the neutral..
------

"direction the power is flowing"
IIRC, the specs on the inverters say they use a VERY small amount of power when the sun isn't out. You may not even be able to get a reading on your Kill-a-Watt.

Cheers,
Rich
PS: I do Electronics, I'm not an Electrician.

[jwxr7]

Originally Posted by Xringer

The way I understand 230VAC is, the neutral line is the return for the two 115VAC lines that make up the 3 wire 230v outlet.


"direction the power is flowing"
IIRC, the specs on the inverters say they use a VERY small amount of power when the sun isn't out. You may not even be able to get a reading on your Kill-a-Watt.

Cheers,
Rich
PS: I do Electronics, I'm not an Electrician.

I'm no electrician either, just EET . I won't speak of other appliances using 240v ac, but in the case of my inverter, the 240v circuit for the inverter carries zero current under normal operation. I have never measured any current in the neutral, with any of my meters. That's why I had to switch things around in order to monitor w/ the Kill-A-Watt. Somewhere in the literature it says the neutral is used for communication.

I have seen nightime increments from time to time from standby loss. Most likely it was close to rounding to the next digit before night and it used enough standby to increment it. I don't count these nightime increments in my production #s I post.

[jwxr7]

I've got a bunch of production #s here from Feb 12th thru Feb 24 2009.
Thurs zero
Fri 220 whrs
Sat 160 whrs
Sun 1260 whrs
Mon 1380 whrs
Tue 1100 whrs
Wed 20 whrs
Thurs 480 whrs
Fri 560 whrs
Sat 100 whrs
Sun 800 whrs
Mon 1320 whrs
Tue 1040 whrs

[Daox]

Doesn't look too bad, but what happened on Wednesday?

[Xringer]

Re: "never measured any current in the neutral".

If you are only using your inverter to supply 230V Only devices, I can see how that could happen.
But, if you plug in a 120V appliance, it's not going to be across the 230 lines,
but one side of the 230 and the neutral.. So, if your 120V 60W lamp comes on, it's getting it's power from 120V & Neutral.

What is your load?? Are you sending the inverter output to a 230V battery charger??

[jwxr7]

It's grid tied. The grid is the load.