Jancauskas Solar  
The System    
   

Three Sharp solar modules with an individual Enphase inverter behind each module.

 

 Fancy on-line monitoring system updated every 5 minutes - click here

  
 

 		  
     
 

Aerial view before the big diseased tree was cut down prior to purchase. Phillips Ave runs almost straight north-south.

  
       
 
The solar panel 240 Vac output enters the meter from the right and then exits out the meter to the main panel on the left. The monitoring system to the left of the meter gets its information from the inverters by communicating over the power lines from a normal wall outlet and then has a LAN cable which connects to the internet router.
  
       

How Much Electricity Should It Produce?

As shown by the solar site survey chart below, the solar access for this site is constrained by mature trees to the east and west as well as the nearby house to the south. The trees block the direct sunlight just about the same time the edges of the wall would. The roof angles are also poor for solar access, so the one wall area chosen was about the only good spot for 'urban solar.'
  Proximity of winter shading from neighbor's house shown below on Jan 31.
 
Adding up the numbers from the center part of the diagram gives the following percentages of the total possible sunlight that the panels see per month.

 

Solar Pathfinder Percentages of total available sunlight            
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
56% 69% 87% 90% 90% 88% 90% 90% 90% 74% 66% 56%
NREL Daily Data kWh/m^2/day
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg
90 degree wall mount 2.9 3.2 3.1 2.9 2.6 2.5 2.6 3.0 3.4 3.5 2.6 2.3 2.88 You lose about 34% for vertical mount
compared to tilted at the "optimal" 39 degrees
Monthly Totals kWh/m^2/month
90 degree wall mount 89.9 89.6 96.1 87.0 80.6 75.0 80.6 93.0 102.0 108.5 78.0 71.3
Pathfinder Percentages x Monthly Totals Total  
90 degree wall mount 50 62 84 78 73 66 73 84 92 80 51 40 832

Annual kWh/m^2
Convert to kWh 22 27 37 34 32 29 32 37 40 35 23 17 365 Annual kWh
per method below
 
 
Compare these value to values calculated using PVWatts V1  
 
PVWatts V1 23 35 33 32 26 22 25 31 36 38 22 17 332 Annual kWh
   (with shading factors)
 

                                                                                                 So the two methods are relatively close

How Does Actual Production Compare?

 

PVWatts  NREL Data  
Month Actual kWh  Expected kWh Performance Variation Expected kWh Performance Variation
Sep 31.9 36.0 -11.3% 40.2 -20.7%
Oct 34.3 37.7 -9.0% 35.2 -2.4%
Nov 40.9 21.8 87.8% 22.6 81.3%
Dec 25.8 17.4 48.8% 17.5 47.7%
Jan 23.0 23.0 0.2% 22.1 4.3%
Feb 23.1 25.5 -9.5% 27.1 -14.7%
Mar 40.0 33.1 21.0% 36.6 9.2%
Apr 38.1 32.4 17.6% 34.3 11.1%
May 24.3 26.1 -6.9% 31.8 -23.5%
Jun 23.3 22.0 5.9% 28.9 -19.4%
           
Total 304.8 274.9 10.9% 296.2 2.9%
Graphed Output Comparisons       
         
         

 

 

And from the table of daily watt-hour production data below you definitely get higher peak production in colder weather, just not a lot of sunny days.
Per the NREL historical data, October should have been the peak production month, but November was unusually high.  Peak production drops off in warmer months because of a the sun being higher and at a less optimal angle to the modules, as well as from reduced output as a result of higher temperatures.

Daily Production 

 

 

How to Convert  kWh/M^2  into actual kWh  (Joe's attempt to figure things out - not a standard calculation methodology)

Yearly incident energy = 832 kWh/m^2/year from NREL data
Each module = 1.2  m^2 (used about 95% of actual area to account for spaces between cells)
Yearly incident energy for 3 modules = 2996 kWh
Module efficiency =  13.1% %
System Efficiency =  87.1% % (from PVWatts V1 calculation)
Expected Annual production = 342 kWh - about 2% of annual usage. (Time to work on other energy efficiency projects.)
Expected daily production = 0.94 kWh - so about 1 kWh/day

 

Yes, even at these low production levels the outside main meter can run backwards (with most everything in the house turned off).  Click here or on the meter to see the video.

But...a meter spinning backwards only records about 80% of the energy so you get a new meter with your interconnect agreement.

  
     

Project Cost

Solar Modules (pre-owned), 3 Sharp NE-170U1 with ground lugs and wire ties $1,136.88
Inverters and interconnect cables $565.07
Energy Monitoring Unit $280.60
Mounting rails and hardware $215.90
Solar output revenue meter $52.08
Miscellaneous wire, conduit, disconnect, meter base, hardware $226.75
Zoning and Electrical Permit $37.35

DP&L Interconnection Agreement Fee

 $95.00

Monitoring System annual renewal fee

 $6.00
Total (without labor): $2,615.63
 
$/watt $5.13

Project Schedule
3/27/2009   Decided to do something, don't wait for grants
4/8/2009   Order NEC Code Handbook
5/15/2009     Initial layout complete
6/3/2009    Zoning approval
6/4/2009   Requested bids on packaged components
6/4/2009   Submit Interconnect Agreement to DP&L
6/10/2009   Selected bidder, order placed
7/29/2009    Interconnect verbally approved by DP&L
8/4/2009    Received rails
8/5/2009   Received modules
8/6/2009   Received inverters
8/19/2009   Mount unistrut
8/22/2009   Mount panels and inverters
8/31/2009   Take out electrical permit
9/2/2009   Panels installed and functional
9/5/2009   Clean up wiring
9/11/2009   City of Dayton Inspection
9/17/2009   Notice to DP&L that system is complete
9/23/2009   DP&L Response to system completion
10/3&4/2009 Ohio Solar Tour
12/21/2009   Request PJM GATS #
12/22/2009    PJM GATS # Approved and Record Created
1/15/2010   PUCO e-filing
1/22/2010   Note from DP&L will schedule meter replacement
1/26/2010   DP&L meter replaced
1/27/2010    Received Interconnect Agreement
1/28/2010   Revceived DP&L Interconnect Invoice
1/29/2010   Signed Interconnect Agreement
2/4/2010   Filed revised affidavit
2/24/2010   GATS notice that still need PUCO number
3/26/2010   Received PUCO certificate
3/29/2010   Updated GATS submittal, noticed Number error
4/1/2010   Called PUCO that number was PA, not OH
4/1/2010   Received new PUCO certificate
4/8/2010   GATS notification of change

Contact: joeandsimone@woh.rr.com

Green Energy Ohio Presentation

Intro to Solar Homework Problem - Design an Off-Grid Solar-Powered Zombie-Proof Bunker

Some Construction Photos

     
     
  Baseline output meter reading of 00000 kWh