Advice on a PV install quote (residential)

[ktriv]

Hello.

Got the following quote from an installer -

1. 3.990 KW DC system with (14) REC Solar panels (8 panels West facing and 6 South facing), SolarEdge SE3800 for $9050. I have asked the installer to consider the price with SolarEdge SE7600.

Thoughts on this configuration and the price? foo1bar this was a quote from sunwork, thanks for the reference.

[JSchnee21]

Welcome ktriv ,

That's an outstanding price -- almost too good to be true. It's rare to see turnkey installs below ~$2.75 per watt. $2.75 to $3.25, sometimes even more, are much more common.

Have you calculated the anticipated kWh of this system based on your location, roof orientations, and pitch (pvwatts.nrel.gov and/or SolarEdge Site Designer)? What percentage of your annual electrical usage will such a small system offset?

Given the unbelievably low price of $9050 / 3990 = $2.27 per watt, any changes / upgrades will undoubtedly significantly increase your cost.

Some things to potentially consider:

1) if roof space is a concern, it seems like it is, you could go with higher wattage panels. It looks like you have 285W panels as is? For added cost you could likely upgrade as high as 320 to 335W to increase your system size and annual production (14*335=4690). That's a 17.5% increase in DC kW, but the cost of the premium panels will likely add at least $0.50 to $0.75 per watt.

2) the new Solar Edge "HD" inverters are smaller and more efficient -- perhaps that's what you've listed above, not sure. I believe they come in 3800, 5000, 6000, and 7600 watt sizes.

3) you might also want to consider consumption monitoring if you want to keep track of your home energy usage.

4) Ethernet connectivity is your best bet for the inverter, otherwise GSM cellular works fine, but uploads less data, less frequently.

5) Be sure to get the extended 25yr warranty for your inverter, its only a few hundred more. The optimizers already include it.

[J.P.M.]

I wonder if that's a prepaid lease ?

What do you pay per kWh now ? How much electricity do you use/year.

What does PVWatts think such a system will produce as a long term system average ?

Run the two orientations and combine the model's output for an estimate of long term system output.

On price: sometimes regional differences will make a difference. I might expect price drops around here once people figure out what the new T.O.U. time schedules will do to system cost effectiveness, but probably not quite that much. Terrible to pay too much. Worse to pay too little.

Caveat Emptor.

[ktriv]

Thanks @JSchnee21 @J.P.M.

Yep, the price appears too good to be true hence trying to figure out whats the gotcha here. Per PVWatts this system will generate 5,960 to 6,308kWh per year which is a bit (100-200KwH) higher than our current annual consumption, however we also own an EV that I plan to charge during off-peak hours.A 3.990 KW DC system is designed to offset approx 95% of our current electrical usage.

1. roof space is not a concern, plenty of room for expansion.
2. SolarEdge 7600 HD is what I had in mind with extended warranty for 25 years.

[ktriv]

Thanks @J.P.M. This is not a prepaid lease. PG&E E1 rate and we're usually in Tier 2, hence 20-30c/Kwh - annual consumption is 5600kwH (approx) Per PVWatts, the expected output is 5,960 to 6,308kWh per year for our location.

@JSchnee21 Thanks for all the suggestions. Roof space is not a concern (lots of room for expansion) and SolarEdge 7600HD is my preference (with 25 yr extended warranty and ethernet connection). This system will offset approx 95% of our current usage and we also plan to charge our EV at home during off-peak hours.

[ktriv]

Thanks JSchnee21, @J.P.M..
We are currently on PG&E E1 plan and during summer months end up in Tier 2 - hence 20-35c/kwh, annual consumption is ~5600kWH. Per PVwatts 5,960 to 6,308kWh per year is expected. This should offset ~95% of our current usage (we also have an EV that we plan to charge during off-peak hours at home after we switch to EV plan)

Roof space is not an issue, plenty of room for expansion and yes, I have not factored in the 100-200$ for inverter 25-year warranty. awaiting the new quote with SolarEdge 7600 HD (with ethernet connectivity)

[JSchnee21]

FYI, there's a new version of the 7600HD with a DC L2 charger if your inverter will be near your garage / driveway. Do you have any shading at all? Personally, I'd consider going with slightly larger system now given the outstanding pricing you're getting -- especially if you're going to upsize the inverter. While you can add panels later, depending on your PoCo and AHJ it may require just as much paperwork, permitting, and inspections as the original system.

[J.P.M.]

Thanks JSchnee21, @J.P.M..
We are currently on PG&E E1 plan and during summer months end up in Tier 2 - hence 20-35c/kwh, annual consumption is ~5600kWH. Per PVwatts 5,960 to 6,308kWh per year is expected. This should offset ~95% of our current usage (we also have an EV that we plan to charge during off-peak hours at home after we switch to EV plan)

Roof space is not an issue, plenty of room for expansion and yes, I have not factored in the 100-200$ for inverter 25-year warranty. awaiting the new quote with SolarEdge 7600 HD (with ethernet connectivity)

For my part, you are most welcome.

Whether you know it or not you will be on Time Of Use ("TOU") rates soon. That will have an impact not only on how much you pay for what you take from PG & E, but also, because TOU pricing times will probably be less favorable to PV generators, any PV system will be less cost effective compared to a PV system working against the old rates.

I'd get informed about what's going to happen as part of the education process.

[cebury]

Where are you at? My own install was $2.90/watt contract signed 23 months ago. If the install is a relatively easy one, it can come down to where you live. If you are in SF in the city, very small rural town, up in the mountains, etc thats a lowball quote. In a decent sized community city like Sacramento, Fresno, Bakersfield, etc prices are much lower.

During Summer, because I use so much of the electricity I generate running the AC I would install the extra panels now vs. Later. Your own usage profile determines what rate plan is best, since someone is home during the day, TOU is not beneficial to me (only the old E6 TOU is just barely better than E1). But if I had several more panels, it would have paid off for me sooner.

Goto your account on PGEs website, what does it show in the Compare Rates section for TOUA and TOUB? Just because you are getting an EV doesnt mean you should switch to an EV plan, especially since you are in Tier1 rates for most of the year. It might be worth the money to buy an extra meter and go with the dedicated EV plan. It really depends on your usage profile.

[ktriv]

@JSchnee21 Thats a great point, checking with the installer/designer for additional panels for an adding another electric vehicle. We do not have a shading issue due to a tree/anything blocking direct sunlight.
@J.P.M. Thanks. I am aware of NEM 2.0 and was under the impression that EV-A is essentially a "TOU" rate. Is that not accurate ? (full disclosure: most of my reading on NEM2 has been on the forums here and PG&E rates).
Thanks for all the great ideas, I'm now considering if a 5KW system might work best with new SolarEdge HD Series (with L2 charger) and switch to EV-A TOU.
cebury : great point. thanks for your input.

[J.P.M.]

@[URL="https://www.solarpaneltalk.com/member/44018-jschnee21"]@J.P.M. Thanks. I am aware of NEM 2.0 and was under the impression that EV-A is essentially a "TOU" rate. Is that not accurate ?.

Yes it is, but you wrote you were on E-1. Planning to change, or having TOU forced upon you gives the same result - a TOU rate will change the cost effectiveness of any system. In either case, if/when the TOU times change will probably will probably also make existing TOU rates less cost erffective for PV.

I'm less familiar with PG & E's rate structures than my own.