I'm considering having a solar panel electrical system installed.

[techman]

Here is a good example of a "good" day. As LD1 says, you only get the peak output around noon.

 

[NorTracNY]

Wow, lots of people throwing around lots of numbers and estimates. Cost of electricity anywhere in the country is easily found on the web.

Maybe I'm wrong for some locations, but in NY, you should NOT be factoring in your delivery fee from your bill if you'll looking at an intertie system. Your price/kwh does not influence the delivery fee. NYS averages 16cents/kwh, but it varies greatly. Long Island is about 24cents, while we are just over 8.

Whether you look to DIY or not, talk to a professional installer. Places here guarentee the output of their systems. If it doesn't produce they pay you. For the panels I'm looking at there is a 0.5% drop every year. So in 20 years they are still guarenteed to produce 90% of what they produce at year 1.

In regards to selling back excess power, in NY anything you produce above what you use in a 12 month period is bought back at wholesale prices. In NY it doesn't pay to produce more than you use. Also, the delivery charge will always exist for people here unless you go off grid.

 

[edlegault]

For techman:

How does a person sell renewable energy credits?

 

[techman]

For techman:

How does a person sell renewable energy credits?

Go to: SRECTrade - Solar Renewable Energy Credit SREC Auction This org only seems to cover several states in the eastern part of the country. There may be something for other states as well. It is based on the laws in some states that they must attain a certain percentage of renewable energy in the state. So the states will buy credits towards that goal.

paul

 

[Rob-D]

Rob:

I see about 32% reduction. Weather, even haze will lower the output. Remember that the panel ratings is based on maximum solar energy of 1000w/m^2, which does not exist in most places, unless you live on the equator. Add temperature effects (hotter means less output), wiring and inverter efficiencies and the losses add up. My biggest factor is weather. Microinverters MAY help, but primarily where part of the array may be shaded. Otherwise the single, central inverter does as well. Also microinverters are relatively new and do not have as clean track record as far as reliability as some conventional inverters have.

PVWATTS gives a very good estimate of power capacity. In my case I am within 5% so far.

paul

Yes, I know PVWATTS and I know about some of the microinverters. I think Enphase made some mistakes along the way especially when they kept changing the MTBF (maximum time between failures) of their inverters, It went from something like 300 years to 100 years. They didn't have an answer when I asked them about it. They may have had electrolytic capacitor problems. My SolatrEdges use ceramics with a much better failure rate. Even with the SMPS (switch mode power supplies), as good as they are today, the capacitors take a beating and electronics on a hot roof only have it worse.

With east/west, like my set up, microinverters really come into play.

Rob

 

[Rob-D]

Wow, lots of people throwing around lots of numbers and estimates. Cost of electricity anywhere in the country is easily found on the web.

Maybe I'm wrong for some locations, but in NY, you should NOT be factoring in your delivery fee from your bill if you'll looking at an intertie system. Your price/kwh does not influence the delivery fee. NYS averages 16cents/kwh, but it varies greatly. Long Island is about 24cents, while we are just over 8.

Whether you look to DIY or not, talk to a professional installer. Places here guarentee the output of their systems. If it doesn't produce they pay you. For the panels I'm looking at there is a 0.5% drop every year. So in 20 years they are still guarenteed to produce 90% of what they produce at year 1.

In regards to selling back excess power, in NY anything you produce above what you use in a 12 month period is bought back at wholesale prices. In NY it doesn't pay to produce more than you use. Also, the delivery charge will always exist for people here unless you go off grid.

Some good points.

 

[vwnotrunning]

Do they make a tracking system that could adjust the PV to acheive a better angle? Or can you utilize some type of reflector system that could increase the output??

 

[Rob-D]

Yes that is my TOTAL rate. It works out the more you use, the less it is per kwh too. But my TOTAL rate averages 11 cents right now. That is the TOTAL of my bill/kwh usage. My last bill was 2396kwh usage and $251. That is about 10.5 cents. And up until about a year and a half ago, it was consistantally 8 cents. Than around november 2010, it started creaping up over about 6 months to the ~11 cents I am at now. And it has remained pretty stable for the last year. I track everything on an excel spreadsheet. For 2010, total yearly usage was 23,607 kwh and 2011 was 23,128.


Even as efficient as those inverters are, look at the WHOLE. You say you have a 6.4kwh system and are on pace to do ~700kwh this month.

We have a little over 12 hrs from sunrise to sunset in march. Using my mentioned 10 hours, and 30 days/month, that would be 1920kwh. Even only using half of the 12 hrs (6 hours) a day, should land you in the 1150 kwh range, yet you come in at ~700kwh.

Now I know that the first few hours and last few do little. I understand that. And understand that mid-day is optimal. I am not trying to dis-credit anything here. Just mearly pointing out how difficult it is to figure these things when you look at a system that is "rated" for X.X kwh, it is hard to correlate that to REAL WORLD numbers. With your system and sharing the info, we are better able to get a REAL Idea of what the production is going to be. Now we know it takes a 6.4kwh system to produce ~700kwh in march and probabally ~1000kwh or so in the summer.:thumbsup:

Knowing stuff like that makes us better able to calculate cost of payback more accuratly than trying to use what the pannels are "rated" at.:thumbsup:

And for me, without net-metering and lower utility rates, COP is still 20+ years and not a viable option at the moment for me.

Yes, and I think it's a good point to establish that there are those who fall outside the benfit of renewables at this time. Again, there are no silver bullets and I think there are a lot of changes ahead.

Rob

 

[Rob-D]

Do they make a tracking system that could adjust the PV to acheive a better angle? Or can you utilize some type of reflector system that could increase the output??

There are solar trackers, some work, some don't work well but the bottom line is that for the cost of a tracker in many places it's cheaper to just add more panels. Also when you add a tracker you add mechanical complexity to a system even if it's the type of tracker that works on hydro fluid.

Rob

 

[SPYDERLK]

I e-mailed my state DOE about some incentives and stuff, and they linked me to that site as well.

According to it, with my 11cent per kwh rate, a 5kw rated system is only going to save me $619/year. And at ~$15k to install ($3/watt) payback is going to be well over 20 years

And thats probabally a pretty realistic figure. They break it down by month. And according to Rob-d's chart, it appears his 6.4kw system is on pace to do 600-700kwh this month. And the pvwatts site lists a 5kw system producing 507kwh for march. So thats probabally pretty close to real world #'s.

Not sure how much location changes it, but If I use a 6.4kw system like rob's, it is showing 648kwh for march.

Glad I found that site with some realistic #'s. Because a novice like me is looking at a 5kw system and thinking it "should" be capable of ~1500kwh or so a month. thats 5kwh x 10hrs/day x 30 days. Obviously in optimal conditions. I didnt realize the inefficiencies were that high. Cause pvwatts says in the peak summer months, a 5kwh system is only making 633kwh.

Even if my electric coop did net metering, I doubt it would matter much on a system that small. and at $15k, even if I take 30% off for the credit, I am still looking at 10k+. And that is still almost a 20 year payback time.

It just isnt there for me yet.

Always keep in mind that the sun delivers 1100W per square meter at the earth surface. Unless you can cant the panel to always stay at a rt angle/normal to the rays it will be difficult to harvest from this potential except during the 4hrs [~10-2] of peak sun. [Photoelectrics go from 10% efficiency upward at escalating cost -- greater demand will ultimately deescalate the cost.] During those 4 you can expect about 100W/M2 of finished electrical power. Following the sun would extend the time, esp on clear days. As tech evolves this will become more economical and capable. For now, staying away from hi tech servo, I would use a conservative yearly figure of 400WHrs/M2/day for finished power. Sizing a collector using that figure factored against your average demand should come close to zeroing your grid intertie meter.
... As you know, I plan to stay away from batteries because the grid is reliable and we have gen backup for any severe interruption. -- also an electric golf cart for micro storage.
larry