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As newbies looking at possibly installing a system on their own home, I see a lot of posts on new systems. I would love to see feedback from owners that are one or two year post install to let us know how their system is performing, maintenance issues if any, etc. How about it, how have your real world results been vs your system projections?
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Went online April 15, 2013 and have generated 14.7 MW to date. System size is 7.6KW AC which consists of (34) Suniva 260w panels with Enphase 215 micros. Zero problems. Check the meter and the monitoring website a couple of times a week and all is good. The only thing I do to them is rinse them off when they get dirty. Pretty easy access and I just rinse them with a hose and use a bucket with a long handle scrubber/ squeegee pole to get the water off so. Been generating really well as of late projected output is a little over 47kw hrs a day and yesterday I had a little over 54kw hrs in fact all week its been over 53kw hrs per day. Generating credits every day to be used later in the year. FWIW my Utility cost for electric only in the preceding year before I went online was $4,037, my first year of having solar I paid $798. Which assumes both years being equal I saved $3,239 not to bad for doing nothing. Definetly worthwhile investment for me. Good luck. -
Just so I understand… So the system has been in place for basically 13 months, and you have produced 14.7MW which converts to 14,700 kW on a 7.6kW system? Wow, I assume you are ecstatic about that. Can you share what your yearly kW usage was prior to the install along with avg monthly bill, and what those numbers were for the past year? Also, where are you located?
thanksComment
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FWIW, sounds a bit high, but possible. FWIW, further confirmation, even if anecdotal, that:
1.) Vendors underestimate solar output by something like 10-20%, using the red herring of conservative design, often to mask selling oversized systems.
2.) Sunpower would do about the same in the same orientation, size, load and location, but would have cost about 20% more.
I'd ask the MGE:
How much $$'s and did you get a performance estimate from the vendor ? Maybe I'm wrong on this.Comment
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I'm here in San Diego Cal (Clairemont). My year before solar usage was 16,169 kw hrs used. Average monthly bill was $337 per month.Comment
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we are not quite at 6 months post install. we went live on 11/30/13. produced 8,941 kwh since then. 11.76kW system with 2 SMA string inverters.
very happy with the performance. we wanted to cover 100% of our usage because we are adding an EV next month to replace our hybrid. just to give you some other numbers - our annual usage was about 18,200, and our Oct 2013 billing statement (our largest of the year) prior to solar was over $700 and maxed out at $0.39/kWh for Tier 4 on that bill.
for the month of April 2014, our net usage was -670 kWh. the year over year comparison was 1,208 kWh in April 2013. we did take a short vacation in April that resulted in approximately -90 savings that we didn't otherwise have the prior year. needless to say we are excited by the prospect of being able to charge our EV with the excess kWh.Comment
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JPM not sure what you mean by how much $'s. Total system cost? The only "vendor" estimate I was using was the Enphase Enlighten website that is used to monitor my system and yes I'm sure it's conservative to a point. They show an estimated production line and an actual production amount for comparison. Per day, week, month, lifetime, etc. and I think they average in non sunny days as well following normal weather patterns I guess.Comment
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My GT 7.755 kW DC system with a 7.5kW inverter went online 1/1/2013. To date, have produced 18.582 MWh. The average production is about 37 kWh per day. My day high was 60.8 kWh(Apr 29,2014) and the usual non-cloudy day production is about 45 kWh. Power use before solar in our all electric house was 25,000 kWh/year. It was reduced by 50%. At my current electric rate, I am saving about $1600/yearComment
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If by vendor you mean contractor/ installer then no. I installed system myself. The only prior estimate I had to go on besides the Enphase site was Pvwatts and I just layed out the system size, azimuth, degree, etc and they estimated 13,218 kw hrs for the first year. Actual production for that first year was 12,980 so I was under by about 10% or so. Hopefully I can catch back up this year if we actually have a summer with some sun.Comment
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To the OP........go to this site:
pvoutput.org
there you can compare over 15,000 (and growing) PV systems from all over the world. You can compare their PV output with expected output base on insolation at their location. You can see their panels and inverters used. You can sort by location to see PV systems in your area.
....and much more....just explore.....
Just be aware that some people believe that people lie about their PV production and that the site has a lot of bogus information. I don't subscribe to that point of view. Just a heads up.Comment
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Toady is the two year anniversary of our installation of a 6.9 kW Sunpower system in central Phoenix. It has produced some 24,650 kWh in that time. There have been no problems apart from the installer going belly-up shortly after my installation. I have a prepaid lease with Sunpower so the installer's demise is of no real consequence to me. It is covering about 2/3 of our usage and offsets all of our peak time needs. It is saving us approximately $1500/year and at that rate, the prepaid lease cost will be covered in about 4.5 years.Comment
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I agree totally at least in the Valley of the Sun. My cases may not apply to all.
I've installed two PV systems in the Valley of the Sun. The first one, in over 3 years of operation, performed 16.7 % better than vendor estimates on energy production. The second system is 20 days shy of one year in-service and is performing at 7.8% better than vendor's projections. Based on my previous system data and others' data going back to 2009 (over 5 years), the data shows the last 11 months of solar production is about 1.72% below the average for the 5 years of the data. If I make that adjustment to my current system to compare with the vendor's estimate, my equivalent production would be at 10% higher than the vendor's projections.
All vendor quotes were very similar in production numbers making adjustments for slight differences in system size. All vendors appeared to use utility rates that were based on the standard residential tariff applied to the amount of generation and would escalate the utility rates using higher rates than what I believe will occur. Also, I did not see any models or data that accounted for excess generation under net metering tariffs in the numbers especially as the vendor's proposed systems grew in size.
So, IMO the vendors are now set up to sell a system significantly larger than one economically needs (with lower estimate of production and higher estimate of savings). Most vendors will likely propose systems to generate 100% of usage with PV or have a zero utility bill. The vendors will sell a system 10-20% larger than needed while showing a proportional savings increase from the additional generation. Heck, if you get a 12%+ (after tax) first year return on this smaller system, why not spend more. Where else can one get a 12% return after tax that will only increase as utility rates rise. However, depending on the utility tariffs, the additional $ spent are likely earning far less than 12% on the additional generation and could tank if / when utilities change net metering and buy back rates.
So bottom line on "how have your real world results been vs your system projections": since I run my models with my assumptions and do not rely on the vendors numbers, my actual generation has been very close to my expected as well as my savings. I am getting what I paid for - not paying for more than I need.
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