Solar Panel Discussion

[Tadol]

I'm trying to get pricing for a small commercial building I have with 5 separately metered retail spaces, but its only about 6,000 sf and Solar City won't do any commercial systems under something like 5,000,000 sf. I got one bid that was quite non-specific from someone else for 68k, and another one with many pages explaining the benefits of going solar but little technical info that was for 98k -

I'm tempted to design and install a system myself, and just hire a commercial electrician to do the electrical part of it. I think I'd use enough panels to get a pretty good price - but I really wish this was all easier -

 

[TonyWilliams]

Honestly, it's just basic skilled labor (electrician, roofer, some manual labor). I'd just do it if you think you can.

Having said that, I think there may be a market for upgrades from existing solar systems that works for you. For instance, I'd like to sell / trade-in my existing SunPower 228w & Enphase M190 system for something bigger. Have you considered buying used? With microinverters, the panels don't even have to match in output.

 

[eschatfische]

If you are served by PG&E, there are no more solar rebates.

Not entirely true. While the state rebates are gone, San Francisco residents served by PG&E still have the GoSolarSF rebate: http://www.sfwater.org/index.aspx?page=133

 

[root710]

EDIT: I see the catch, the .62/kW only applies to usage above 200% of baseline, so a typical solar user will never see the credit at $.62, rather the typical peak credit would be reduced to 18 or 19 cents. Not a good idea.

Since this thread is about solar I will say 62 cents is a great price to sell your excess solar power produced on-peak.

If it's available to net metering customers, that's true. The hours for peak / off peak rates are the same as the DR SES schedule. It says experimental rate in the Tariff book information sheet. Maybe I need to check into this one too. Then I could charge a second car for free.

dstjohn99, did you ever look into SDG&E's DR-TOU rate? I thought it would be worth comparing to your other spreadsheet analysis. I thought I had heard somewhere that this was the best rate for getting the most bang for the buck from PV.

 

[dstjohn99]

dstjohn99, did you ever look into SDG&E's DR-TOU rate? I thought it would be worth comparing to your other spreadsheet analysis. I thought I had heard somewhere that this was the best rate for getting the most bang for the buck from PV.

No. Based on the combination of the TOU and tiered usage in the DR-TOU rate schedule, you would only get a $.62 per kW credit if you were above 200% of your baseline usage during peak hours. Most solar systems drive usage down to lower tiers, or less than zero at peak times. So my assumption is that you would never get the high rebate unless you used a lot of energy during peak. This might be a good rate for purchasing a solar system to just shave off the peak usage in the upper tier.

 

[RAVev4SF]

I just got a quote for a 17 panel system which is rated at 4.4 kwh from Sunrun. Since it was a Costco vendor I thought they might be a good company to work with. With zero down my initial monthly bill would go down $50 but would steadily increase 2.9% over 20 years. The best option seems to prepay the 20 years at roughly 11 cents / kwh (roughly $12,750, I'll also be getting $2,700 from the San Francisco Water Dept. for their go solar program and a $500 rebate from Sunrun), which should only leave me with a small bill from PG&E. My questions for those who have panels already are, are all panels equal, which are "better" or "cheap" materials same for the type of inverter I should ask for in the quote. The Sunrun rep said the system should cover 75 to 80% of my usage and I'll keep my TOU from PG&E. I've talked to Verngo and Sungevity but their prices seem a little higher, I'll talk with Solar City before I pull the trigger. Any advice out there.

 

[james]

I'm closing in on a system with "Your Energy Solutions" using a 3.35KW system (10 Sunpower panels with micro Powerone inverters) The all black Sunpower panels are more $ but more efficient. $16K out the door. I will probably put it on a home equity line of credit and take the 30% tax credit. I expect this system to cover 80 - 90% of my energy costs.

I also got quotes from SolarCity and Sungevity but really liked working with Your Energy Solutions. They are very professional and offered more options. You might want to check them out.

 

[Dsinned]

FWIW, I had a 4.25kW (17 - 250W panels) system installed on my home's 2nd story roof almost two years ago. The installation was done by Petersen Dean, headquartered in the East (SF) Bay. I "purchased" the system outright and after the Fed's 30% tax credit, my total cost was less than $11k. The system has Canadian Solar 250W panels and M215 Enphase Microinverters, with 100% remote monitoring of each module. So far, the system has generated a total of ~13MWh. This comes very close to "net zero" year round. I am only paying the monthly PG&E "service fee" - typically <$5/month - for all electric power consumption at my residence in San Jose.

I am very satisfied with my system installation and reliability of the panels and microinverters and the ability to completely monitor the entire system from the comfort of my home or remotely over the Internet.

 

[agleung]

SCE has discontinued their TOU-TEV plan and are offering 3 different TOU-D plans.

It seems TOU-D-A is better for EV charging at night whereas TOU-D-T suits residential with solar PV.
If my solar PV will cover most of my usage in kWh, is there a reason to go with TOU-D-A over TOU-D-T?
Any fellow SCE/solar PV/EV users care to chime in? Thanks.

 

[dstjohn99]

So for TOU-D-T if you are generating excess during peak hours, do you get at .34 credit or .49?

 

[pchilds]

So for TOU-D-T if you are generating excess during peak hours, do you get at .34 credit or .49?

Yes, but you are paying .13 or .27 to charge at midnight.

 

[smkettner]

So for TOU-D-T if you are generating excess during peak hours, do you get at .34 credit or .49?

Yes. You get both. I mean you get either. Depends on the baseline prorata allocation. So first you get 34 then 49 on a sliding scale.

 

[smkettner]

Any fellow SCE/solar PV/EV users care to chime in? Thanks.

Since you are close to even on kWh I doubt it will matter much. You will probably have a monetary credit that gets cancelled at end of the year because you did not produce more than you consumed with either rate plan.

If you have a net kWh credit SCE may pay you some money but it will not be at any of these retail rates.

 

[miimura]

So for TOU-D-T if you are generating excess during peak hours, do you get at .34 credit or .49?

If your net usage for that billing period is below 130% of baseline, you only get $0.34/kWh credit. If your net usage is over that level, then the time periods are assigned by their proportion. For example, if 25% of your net usage is during the peak period, then 25% of Tier 1 will be billed at Peak rate, and so on, whether positive or negative.

I've fabricated an example below. In order to get the usage above 130% of baseline, I added a whole bunch extra Off-Peak usage. This would be like charging a second car.

You can see above that you would be credited $8.55 for 26.65kWh above 130% of baseline whereas you would only be credited $5.75 for 56.64kWh below that. That is based on a 10cent to 32cent tier spread from PG&E.

[Edit: added example calc]

 

[drmanny3]

I am in the same situation trying to figure out which system to go with. This last year it was pretty hot and I found us turning on the air right at 6:01 pm to try and bring the temp down. While we got credit during the day On Peak first at the level 1 then at the level 2 we seemed to burn a lot of that during the 6:01 to about 10:00 pm. And if we ran the air at night 10:00 to about midnight we ended up in level two at the off peak. That rate was fairly high. We then burned up what ever we had left charging the Rav4EV. We have great insulation but our house never the less heats up. We can keep it fairly acceptable till about 4 or 5 pm. By then the heat has worked its way through the house. The interior gets to about 83 or 84 degrees by 6 pm. So of course we turn on the air. With respect to the rates I like the B except for the $16 charge per month. I understand that SCE is trying to balance out the energy production and consumption. I am not sure we can go till 8:01 pm during the hot summer before turning on the air. I noticed a mistake in the chart for Option B. Off Peak is stated at 6 pm - 10 pm It should be 8 pm - 10 pm to correspond to the On Peak which is 2 pm - 8 pm. I am hoping to participate in the sub meter program that Tony has been in for several years. I applied and am waiting for the EMotorwerks to meet the SCE requirements. That would then separate me from having to balance the charging of the car with maximizing the application of our solar panels and our comfort level. I am trying to review my solar production against the consumption. SolarCity allows me to look on a daily basis with respect to what I produce, but now what I consume. What I have is free. They did offer a software package that looked at both consumption and production allowing you to see where you were at any given moment. I understand that was an expensive add on.

Month............Electricity produced(SolarCity)kwh...........Consumption(SCE) Total............SCE On Peak............SCE Off Peak............SCE Super Off Peak.............SCE Super Off Peak/Total
Jan................406.....................................................589.........................................-63..........................326........................326....................................55%
Feb................446.....................................................647.........................................-82..........................250........................478....................................74%
Mar................634.....................................................385.......................................-217..........................199........................403...................................105%
Apr................784.....................................................269.......................................-315..........................104........................480................................... 178%
May...............848.....................................................350.......................................-324..........................144........................532................................... 151%
Jun................855.....................................................167.......................................-346..........................117........................396................................... 236%
Jul.................805.....................................................617.......................................-278..........................382........................513..................................... 83%
Aug...............836.....................................................599.......................................-327..........................315.........................612....................................102%
Sep...............680...................................................1068.......................................-150...........................573.........................644....................................60%
Oct................531....................................................648.......................................-152...........................351.........................450....................................69%
Nov...............415....................................................826.........................................-50...........................307.........................571....................................70%
Dec...............318....................................................695........................................+38...........................283.........................375....................................54%




Thus far I am into my ninth month with SCE for billing purposes. I currently owe $330 for the nine months. I will probably incur more charges for Jan and Feb and probably pick up some credits for Mar. My overall SCE bill for a year will probably be around $400 this year. That is not too bad given that we had a pretty hot summer and I drove the Rav4EV about 10,000 miles. Our Prius gets 40 mpg. If I drove 10k miles at $4.00 per gallon the cost would have been about $1000. Had I driven my NSX-T with supercharge the cost would have been $2200. So I am pretty happy. My dilemma is which TOU do I choose. The A or B

 

[pchilds]

SCE screwed up and sent me a check for $28, the retail value of my unused electric credit. Anyone else get a check that they shouldn't have from SCE?

 

[agleung]

I am in the same situation trying to figure out which system to go with. This last year it was pretty hot and I found us turning on the air right at 6:01 pm to try and bring the temp down. While we got credit during the day On Peak first at the level 1 then at the level 2 we seemed to burn a lot of that during the 6:01 to about 10:00 pm. And if we ran the air at night 10:00 to about midnight we ended up in level two at the off peak. That rate was fairly high. We then burned up what ever we had left charging the Rav4EV. We have great insulation but our house never the less heats up. We can keep it fairly acceptable till about 4 or 5 pm. By then the heat has worked its way through the house. The interior gets to about 83 or 84 degrees by 6 pm. So of course we turn on the air. With respect to the rates I like the B except for the $16 charge per month. I understand that SCE is trying to balance out the energy production and consumption. I am not sure we can go till 8:01 pm during the hot summer before turning on the air. I noticed a mistake in the chart for Option B. Off Peak is stated at 6 pm - 10 pm It should be 8 pm - 10 pm to correspond to the On Peak which is 2 pm - 8 pm. I am hoping to participate in the sub meter program that Tony has been in for several years. I applied and am waiting for the EMotorwerks to meet the SCE requirements. That would then separate me from having to balance the charging of the car with maximizing the application of our solar panels and our comfort level. I am trying to review my solar production against the consumption. SolarCity allows me to look on a daily basis with respect to what I produce, but now what I consume. What I have is free. They did offer a software package that looked at both consumption and production allowing you to see where you were at any given moment. I understand that was an expensive add on.

Month............Electricity produced(SolarCity)kwh...........Consumption(SCE) Total............SCE On Peak............SCE Off Peak............SCE Super Off Peak.............SCE Super Off Peak/Total
Jan................406.....................................................589.........................................-63..........................326........................326....................................55%
Feb................446.....................................................647.........................................-82..........................250........................478....................................74%
Mar................634.....................................................385.......................................-217..........................199........................403...................................105%
Apr................784.....................................................269.......................................-315..........................104........................480................................... 178%
May...............848.....................................................350.......................................-324..........................144........................532................................... 151%
Jun................855.....................................................167.......................................-346..........................117........................396................................... 236%
Jul.................805.....................................................617.......................................-278..........................382........................513..................................... 83%
Aug...............836.....................................................599.......................................-327..........................315.........................612....................................102%
Sep...............680...................................................1068.......................................-150...........................573.........................644....................................60%
Oct................531....................................................648.......................................-152...........................351.........................450....................................69%
Nov...............415....................................................826.........................................-50...........................307.........................571....................................70%
Dec...............318....................................................695........................................+38...........................283.........................375....................................54%




Thus far I am into my ninth month with SCE for billing purposes. I currently owe $330 for the nine months. I will probably incur more charges for Jan and Feb and probably pick up some credits for Mar. My overall SCE bill for a year will probably be around $400 this year. That is not too bad given that we had a pretty hot summer and I drove the Rav4EV about 10,000 miles. Our Prius gets 40 mpg. If I drove 10k miles at $4.00 per gallon the cost would have been about $1000. Had I driven my NSX-T with supercharge the cost would have been $2200. So I am pretty happy. My dilemma is which TOU do I choose. The A or B

If I read your numbers correctly, your real consumption is production + consumption, i.e. all your production was consumed in any given months. e.g. Jan is 406 + 589 = 995 kWh. BTW what is your system size?

 

[drmanny3]

My system is 5.1 AC or 4.63 DC. Your correct in that for Jan it is 406 plus 589 = 995 kwh. Because we are on TOU we get credit for the On Peak when it is shown as -negative. The credit is more than a 1.1 and helps keep the costs down.
Manny

 

[root710]

I am looking at purchasing a system with LG PVAC modules. They are 300 watt modules with built in LG micro inverters. Thus each panel puts out AC current and they are pretty much plug and play for replacing or adding on to the system. Being built specifically for these panels the micro inverters appear to be very efficient and I would expect will have minimal clipping and ideal optimization of the energy production.

I like not having hi-voltage DC current on my roof, all the associated conduit and the bulky string inverter associated with the standard systems.

Does anyone have experience with AC modules or have any comments about such a system? These LG panels are new so I can't find any reviews of the panels online. It seems that historically LG makes a good PVAC product. Panel efficiency is something like 18.5%.

Comments?

 

[smkettner]

SCE screwed up and sent me a check for $28, the retail value of my unused electric credit. Anyone else get a check that they shouldn't have from SCE?

Probably the Climate Credit that apparently is refundable.