Building Reserve and Using KWH

[bcroe]

Those are very good numbers! So my question is; you
said you gifted 5,600kW back to the PoCo. Did the PoCo wipe your credits to
zero on your interconnect anniversary? Rade

I started out pretty obsessive about energy consumption
when I moved here in 2004. I tracked down every load on
some 60 circuits, and was eventually able to eliminate some
240W of Vampire loads, coming to some 2100 kWh a year.
Many of these loads were outside the house (garage door
opener, attic fan, etc), so they did not even contribute at an
inefficient level to heating the house. Many were reduced
from 4 or 15W, to well under 1W. All this was done before
going solar in 2013. In 2018 use of mini split heat pumps
allowed adding in without energy purchases, some items
previously not allowed, including frequent air circulation
thru my electronic air filter, a summer time dehumidifier,
and continuously warming a shop building.

I did not give the PoCo back 5600 kW, the most power I can
generate is 15kW. I did accumulate an energy surplus of
5600 kWHOURs by the (April 2) reset day, which means
starting the next Net Metering year at zero under my plan.
Surplus is a gift to the PoCo, not to worry as it cost me
nothing extra to generate. This is a zero carbon footprint,
zero energy purchase operation, not a for profit. Bruce Roe

[Mike 134]

Northern Illinois ComEd is the power company for me. If i have a surplus on my April bill it just goes POOF!!! Not even a thank you for the free KWHs from the power company. Then the "new year" starts again building credits (I hope).

[Rade]

Those are very good numbers! So my question is; you said you gifted 5,600kW back to the PoCo. Did the PoCo wipe your credits to zero on your interconnect anniversary?

I'm coming up on my 1st anniversary on May 10; I'm kinda hesitant to celebrate for the moment. As I often complain, our house is a bit of a power hog and right now, I am at a 1,220kW deficit if we are going to break even next winter. But the weather is warming, the electric furnace has been turned off and our power meter is finally, consistently clicking downward (more power back to the grid than the house is using). >If< the weather continues to cooperate, we may make up that deficit by our anniversary. In May of last year, we generated 1,900kW of power (peak for the year).

And that brings me back to my question - Our anniversary is on May 10. I'm wondering if any credits I am (finally) generating will be zeroed out at that time? No one in any know seems to be able to answer that; our PoCo website only states that my credits will continue to accrue and then be used towards standard billing once we have to begin pulling from the grid. I guess I will find out on May 12 when the next statement comes in. We churned through our credits by February.

I think it was you who advised to just be patient; thank you! Yes, all in all, during the first 4 or so months, we had about a month total of new system configuration bugs that knocked our generation down during peak sun season. The bugs seem to have been worked out and our solar architecture has been running rather well for many months now. Looking forward to... not being so damn obsessive about power consumption.



Rade

[bcroe]

Net Metering year 11 concluded, generated about 28,800 kWh.
Still running the original panels and inverters. With the relatively
warm and somewhat less cloudy winter, the surplus was around
5,600 kWh given as a gift to the PoCo. The only original wiring
is the 220 ft buried DC conductors between the combiner box
and the inverters. Bruce Roe

[Rade]

POCO is Power Company.

Merci!

[Ampster]

Question: What is a "POCO"? It's not an acronym I am familiar with.

POCO is Power Company.

[Rade]

Question: What is a "POCO"? It's not an acronym I am familiar with.

[bcroe]

This has been a year of very little rain, but local farmers managed to
get an average corn crop anyway. There were a lot of clouds that
did not produce any rain, just hurt solar. As of 1 Nov NetMetering
winter reserve matched my past best, 14,000 kWh. Usually it then
starts to reduce, but record warm weather and a few more sunny
days have it still holding 13 Nov. With any luck there will be plenty
of kWh thru this winter. Equipment has been doing well since the
switch repair.

Bruce Roe

[PNPmacnab]

Once again Nyle announced the e8 water heating heat pump adapter,
might soon be available. It is still in the process of being Energy Star
certified, UEF tested, UL tested, and other things. If I ever get one,
the energy reserve might be exhausted, better than giving it away.

IMGP2436.jpg

A friend of mine just got a e8 end of May and finally got around to installing it. He is quite impressed. He got build #4, just after the ones sent off for regulatory testing. So, I guess that is still experimental as it has no certification. Surprised it is a 120V unit with the market being primarily commercial. He uses it in singe pass full temperature output.

[bcroe]

Bruce, I use silver conductive grease on every connection and a torque screwdriver or wrench. Not to be confused with dielectric grease. It’s expensive but we’ll worth it IMO. Use very sparingly as excess will short a circuit. If + and - are near each other.
Never had a connection failure in my system.

I am again bringing the main PV wiring into a more regular review,
even using a temp gauge to check for a box heating up after a
few hours at max power. I will be using some kind of terminal
protection on everything now. And spare shutdown assemblies
are prepared and sealed, just in case. The post mortum hints to
me, the issue has been the aluminum terminal block that came
bolted to the DC shutdown switch assembly. I am replacing all
of these with copper terminal blocks + anti corrosion stuff.

This year the big solar item is the smoke. Usually not so common
here in nothern IL. Even smoke not looking so thick, has a big
impact on solar energy. I am used to seeing the 15KW system
peaked out for nearly 8 hours a day many times. But recently it
has trouble getting up to the full 15KW capacity. Even when the
sky is not cloudy, production might be down 20% or more. Still
the array is fighting it, energy reserve is about 7.8MWh vs 8MWh
best at this date.

Then there is air quality, worst numbers I have ever seen. But
smoke containts physical particulate, which my electronic air filter
can remove no matter how small. The furnace blower operates it
around 20 minutes every hour. This really works, even before the
smoke, I could see that the dust particles in a beam of sun were
way down. The overall PV system produces enough energy to
allow this luxury (?) at no extra cost beyond cleaning the filter.
The blower motor (a standardized direct drive) was recently
replaced as the original was about to fail. All motor wires were
the same, though I did need to touch up the impeller balance.

Bruce Roe

[DanS26]

Bruce, I use silver conductive grease on every connection and a torque screwdriver or wrench. Not to be confused with dielectric grease. It’s expensive but we’ll worth it IMO. Use very sparingly as excess will short a circuit. If + and - are near each other.

Never had a connection failure in my system.

[Mike 134]

After a decade the 15KW system here has again developed
wiring problems. The twin 7.5KW inverters normally are a
match to around 1%, but lately EAST was lagging some. A
quick check with the clamp on DC ammeter indicated all
strings were close to a match. More checking, after half a
day running full power (that is up to 8 hours with this
configuration) the EAST DC disconnect box was getting pretty
warm.

As usual I set up a night work light and waited for the darkness.
Inside the Square D 361 box a 6 gauge wire looked like it
was cooking its insulation. The 361 is rated 30A against
the 22 I run, and 600VDC against my 400, 3 contact positions.
Something about the plus array wire was making poor contact
and getting ready to burn out. It was not my wire clamp screw.

I had this same failure on another contact years ago, I had
just moved the wires to the spare position. Something was
not making good contact, not sure if it was the bolts holding
metal together, or the switch contact. Is there a contact lube
that should be used on these?

Fortunately I have a lot of spare parts, and these boxes are
designed so a few screws from the open door side allow
replacing whole units. I found a nice switch section, made
sure all its screws were pretty tight, and soon had it installed.
Hand test today indicated proper cool operation.

There are plenty of the 361 outdoor boxes on Evil Bay, some
with 600V fuses (that I do not need), and some with just a
switch. Bruce Roe PVburnedDC.jpg

Is that brownish color light rust on the rivets? Perhaps some condensation over the past 10 years leading to the poor connection.

[bcroe]

After a decade the 15KW system here has again developed
wiring problems. The twin 7.5KW inverters normally are a
match to around 1%, but lately EAST was lagging some. A
quick check with the clamp on DC ammeter indicated all
strings were close to a match. More checking, after half a
day running full power (that is up to 8 hours with this
configuration) the EAST DC disconnect box was getting pretty
warm.

As usual I set up a night work light and waited for the darkness.
Inside the Square D 361 box a 6 gauge wire looked like it
was cooking its insulation. The 361 is rated 30A against
the 22 I run, and 600VDC against my 400, 3 contact positions.
Something about the plus array wire was making poor contact
and getting ready to burn out. It was not my wire clamp screw.

I had this same failure on another contact years ago, I had
just moved the wires to the spare position. Something was
not making good contact, not sure if it was the bolts holding
metal together, or the switch contact. Is there a contact lube
that should be used on these?

Fortunately I have a lot of spare parts, and these boxes are
designed so a few screws from the open door side allow
replacing whole units. I found a nice switch section, made
sure all its screws were pretty tight, and soon had it installed.
Hand test today indicated proper cool operation.

There are plenty of the 361 outdoor boxes on Evil Bay, some
with 600V fuses (that I do not need), and some with just a
switch. Bruce Roe PVburnedDC.jpg

[bcroe]

Here I am again, smoke from wild fires in the NW is sending haze over
the IL area again. While not terribly severe, it is enough to cause the
inverters to drop out of clipping (about 7600W each), to more like 7300
or 7400W. Bruce Roe

[DanS26]

I recently added an antenna to my mid-1800's barn with a very slick metal roof.........

IMG-0756.jpg