LG 305s with SolarEdge Inverter - Los Angeles

[DanKegel]

My house is 25 years old and does not hold heat (or coolness in the summer) well. I am considering having some newer windows put in. Are there people/companies that will evaluate the over all energy efficiency of your home and provide ways to improve it?

There are probably some more cost effective changes than new windows, but yeah, new windows can help.

There are most definitely companies that will do overall energy audits & offer improvements.
There are even subsidies for making those improvements. See http://www.energyupgradeca.org/
But don't pay too much for an audit... comparison shop first.

And you can do a lot yourself. For instance, you can get a kill-a-watt meter for about $30
that will tell you what any one plug is using. I found out my fridge was drawing way too much power that way.

I don't foresee doing anything that will increase our consumption. We already have an AC hot tub and ovens. If anything we may change or get rid of those. I do have mostly LED lights and dimmers about the house. I honestly can't see why we are using so much electricity. Last year was around 13,000kWh in a 2,800 sqft home.

So about 33 kwh/day on average? Yeah, you can probably do better.

No matter what your goal with going solar is, you can get partway there a lot cheaper by figuring out where your power is going, and fixing that first.

And then go solar for enough of the rest to get you well down into Tier 1.

[thejq]

I just got an updated quote from the first installer for 24 LG-305s using a SolarEdge 6kW inverter with Power Optimizers. The price is $24,156 which comes out to about $3.30/W.

So since they can do the SolarEdge inverter, I guess the million dollar question is the SolarEdge Inverter or the Enphase micro-inverters.

Also is a 6kW Inverter large enough for a 7.3 kW system?

Why did you change from 20 to 24 panels? Otherwise the 6K inverter would match very well. Your south facing roof is ideal for energy production, so the 7.3 KW system with 6KW inverter will clip quite often.

I'm not too familiar with SMA's monitoring capability, but SolarEdge comes with life time per-panel monitoring for free. Enphase charges $250 I think. The latter two also allow you to integrate with pvoutput.org if you're into that.

Besides shading, some panels can also be partially obstructed occasionally by bird droppings, leafs or dirt. The high temperature at where the micro-inverters operate can be a reliability and maintenance concern. The optimizer uses ceramic caps and is significantly simpler, hence in theory more reliable under high temperature.

[J.P.M.]

I do not have any shading assuming they can fit the panels on the two parts of the roof they say they can. If they have to use another part of the roof there would be some shading in the late afternoon from a tree and chimney.

I just got an updated quote from the first installer for 24 LG-305s using a SolarEdge 6kW inverter with Power Optimizers. The price is $24,156 which comes out to about $3.30/W.

So since they can do the SolarEdge inverter, I guess the million dollar question is the SolarEdge Inverter or the Enphase micro-inverters.

Also is a 6kW Inverter large enough for a 7.3 kW system?

I would like to also reduce my energy consumption, but I have not gone down that path yet. This size system would be covering 70-80% of my energy.

Suit yourself, but if you go down the use reduction path before you go down the solar path, your bill will go down more eectively and any resulting system will be smaller. Solar first and you'll reduce the incentive to reduce usage. Any resulting system will be larger ( more $$ upfront), and you'll have done the less economically effective stuff (solar) first.

[SunStalker]

Great. Are both sections south-facing, or is one section west-facing?



They're pretty similar. Have you investigated reliability of each? With 24 units, that's plenty of chances for failure.



The extra power would probably just be dumped. How much of the day do you expect to be generating more than 6KW?

See also

http://www.solaredge.com/files/pdfs/inverter_dc_oversizing_guide.pdf

and

http://enphase.com/eblog/2013/%E2%80%9Cover-sizing%E2%80%9D-v-%E2%80%9Cright-sizing%E2%80%9D-new-ideas-for-one-of-solar%E2%80%99s-oldest-debates/

I regret not doing that before installing my first solar system and an AC-powered hot tub Thinking about energy use in the whole house might have saved me some money.

Do you at least have efficient light bulbs? (/me loves the Osram ones at Lowe's.)

All three sections of the roof that I am considering are south facing. I am leaning toward the string inverter because the lack of info I can find on the reliability of the micro inverters and like you I am concernded about having 24 of them on that hot roof.

My house is 25 years old and does not hold heat (or coolness in the summer) well. I am considering having some newer windows put in. Are there people/companies that will evaluate the over all energy efficiency of your home and provide ways to improve it?

I don't foresee doing anything that will increase our consumption. We already have an AC hot tub and ovens. If anything we may change or get rid of those. I do have mostly LED lights and dimmers about the house. I honestly can't see why we are using so much electricity. Last year was around 13,000kWh in a 2,800 sqft home.

[DanKegel]

I do not have any shading assuming they can fit the panels on the two parts of the roof they say they can.

Great. Are both sections south-facing, or is one section west-facing?

So since they can do the SolarEdge inverter, I guess the million dollar question is the SolarEdge Inverter or the Enphase micro-inverters.

They're pretty similar. Have you investigated reliability of each? With 24 units, that's plenty of chances for failure.

Also is a 6kW Inverter large enough for a 7.3 kW system?

The extra power would probably just be dumped. How much of the day do you expect to be generating more than 6KW?

See also

http://www.solaredge.com/files/pdfs/inverter_dc_oversizing_guide.pdf

and

http://enphase.com/eblog/2013/%E2%80%9Cover-sizing%E2%80%9D-v-%E2%80%9Cright-sizing%E2%80%9D-new-ideas-for-one-of-solar%E2%80%99s-oldest-debates/

I would like to also reduce my energy consumption, but I have not gone down that path yet. This size system would be covering 70-80% of my energy.

I regret not doing that before installing my first solar system and an AC-powered hot tub Thinking about energy use in the whole house might have saved me some money.

Do you at least have efficient light bulbs? (/me loves the Osram ones at Lowe's.)

[SunStalker]

$3.45 is a pretty good price.

I agree, SolarEdge is worth considering.

Is your house on http://solarmap.lacounty.gov ? (Maybe PM me your address?)

Do you have any shading?

Have you already reduced your energy consumption and/or gotten an energy audit?

What are your goals?

I do not have any shading assuming they can fit the panels on the two parts of the roof they say they can. If they have to use another part of the roof there would be some shading in the late afternoon from a tree and chimney.

I just got an updated quote from the first installer for 24 LG-305s using a SolarEdge 6kW inverter with Power Optimizers. The price is $24,156 which comes out to about $3.30/W.

So since they can do the SolarEdge inverter, I guess the million dollar question is the SolarEdge Inverter or the Enphase micro-inverters.

Also is a 6kW Inverter large enough for a 7.3 kW system?

I would like to also reduce my energy consumption, but I have not gone down that path yet. This size system would be covering 70-80% of my energy.

[DanKegel]

$3.45 is a pretty good price.

I agree, SolarEdge is worth considering.

Is your house on http://solarmap.lacounty.gov ? (Maybe PM me your address?)

Do you have any shading?

Have you already reduced your energy consumption and/or gotten an energy audit?

What are your goals?

[sensij]

Without shade, it is hard to say that there will be very much difference between a string inverter, microinverters, or optimizers. There are a few mechanisms by which the panel level MPPT might outperform a single string inverter, but I have not seen any data that shows those marginal performance boosts are enough to justify the cost premium.

Without shade, I've come to see choosing SolarEdge or Microinverters as more or less equivalent, and mostly in the realm of engineering curiosity more than actual performance. If you like to tinker and actually care about what each panel is doing, there are reasons why you might want SolarEdge and other reasons microinverters could be interesting; there is not a globally correct choice. Installers will talk bad about each other's products all day long, and I don't put much weight to those opinions.

If you just want a lower bill electric each month and don't want to think about your system any more than that, without shade, a string inverter may be just as cost-effective as the alternatives, and probably more so. Careful review of systems on an aggregation site like PVOutput.org can support or refute this idea, but it will take some time and effort to compare the data carefully enough to be sure.

[SunStalker]

I'm almost ready to pull the trigger on a solar system for my home. For reference, here are the quotes I have gotten so far (No incentives included):

Size/Panels/Inverter/Cost/$ per Watt
6.1 20xLG 305 Enphase M250 $21,045 $3.45
6.9 21xSunPower E20-327 SMA SB6000TL-US-22 $39,799 $5.80
7.0 27xREC Solar REC260PE SolarEdge SE6000 $27,500 $3.92
5.0 20xHyundai 250 SolarEdge $18,511 $3.70


I am currently leaning toward the LG Panels, but I am not feeling comfortable with the micro-inverters. The company say they could to an SMA string inverter for $0.20 less per Watt. I would like to get the the LG Panels with a SolarEdge inverter with Power Optimizers. Every company except for the one using the micro-inverters said to stay away from them. I shouldn't have any shading issues on any of the panels.

First how are the quotes looking? Second, is their an installer in the Los Angeles area (I'm in Northern Los Angeles in Santa Clarita) that will do the LG panels with the SolarEdge inverters? If so please PM me details.

Thanks for the help.