Grid Tie Tilt Kits

Go back in time, maybe just 5 or more years, back to the days of solar trackers and tilted arrays. Those were the days! Now all this great technology has given way to the inevitable: Low PV prices.

If you live in Christchurch and want a Grid Tie system then 33 Degrees is the ideal angle for mounting your array.

If aesthetics are important then to keep a low profile we would have designed for a landscape mounting configuration so the array(s) would be longer and lower.

But now you might want to look at this data comparison and perhaps have your array flat mounted to the roof and spend the tilt kit money on a couple of extra panels and larger inverter.... Just a thought but the figures stack up well....

33 degrees:


Station Identification
City: Christchurch
Country/Province: NZL  
Latitude: 43.48° S
Longitude:     172.55° E
Elevation: 34 m
Weather Data:     IWEC
PV System Specifications
DC Rating: 3.20 kW
DC to AC Derate Factor: 0.850
AC Rating: 2.72 kW
Array Type: Fixed Tilt  
Array Tilt: 33.0°
Array Azimuth: 0.0°
Energy Specifications
Energy Cost:     0.2800 dollars NZL/kWh
 
Results

Month
 
Solar Radiation
(kWh/m2/day)
AC
Energy

(kWh)
Energy
Value

(dollars NZL)
5.75      453  126.84 
5.67      407  113.96 
4.65      371  103.88 
3.67      288  80.64 
2.56      204  57.12 
2.09      162  45.36 
2.23      180  50.40 
2.96      242  67.76 
4.67      366  102.48 
10  5.01      407  113.96 
11  5.78      451  126.28 
12  6.05      482  134.96 
Year  4.25      4012  1123.36 

 
10 degrees (same sized array): (less a tilt kit $736 less Labour about half a day $260)
Station Identification
City: Christchurch
Country/Province: NZL  
Latitude: 43.48° S
Longitude:     172.55° E
Elevation: 34 m
Weather Data:     IWEC
PV System Specifications
DC Rating: 3.20 kW
DC to AC Derate Factor: 0.850
AC Rating: 2.72 kW
Array Type: Fixed Tilt  
Array Tilt: 10.0°
Array Azimuth: 0.0°
Energy Specifications
Energy Cost:     0.2800 dollars NZL/kWh
 
Results

Month
 
Solar Radiation
(kWh/m2/day)
AC
Energy

(kWh)
Energy
Value

(dollars NZL)
6.02      480  134.40 
5.57      402  112.56 
4.26      340  95.20 
3.11      242  67.76 
1.99      152  42.56 
1.55      115  32.20 
1.70      131  36.68 
2.42      194  54.32 
4.09      321  89.88 
10  4.81      393  110.04 
11  5.93      466  130.48 
12  6.42      518  145.04 
Year  3.98      3753  1050.84 
Same 10 degree angle but with 2 more panels and a larger inverter (an extra $1395 less a tilt kit $736 less Labour about half a day $260)

Station Identification
City: Christchurch
Country/Province: NZL  
Latitude: 43.48° S
Longitude:     172.55° E
Elevation: 34 m
Weather Data:     IWEC
PV System Specifications
DC Rating: 3.60 kW
DC to AC Derate Factor: 0.850
AC Rating: 3.06 kW
Array Type: Fixed Tilt  
Array Tilt: 10.0°
Array Azimuth: 0.0°
Energy Specifications
Energy Cost:     0.2800 dollars NZL/kWh
 
Results

Month
 
Solar Radiation
(kWh/m2/day)
AC
Energy

(kWh)
Energy
Value

(dollars NZL)
6.02      540  151.20 
5.57      452  126.56 
4.26      382  106.96 
3.11      272  76.16 
1.99      171  47.88 
1.55      129  36.12 
1.70      147  41.16 
2.42      219  61.32 
4.09      361  101.08 
10  4.81      442  123.76 
11  5.93      524  146.72 
12  6.42      583  163.24 
Year  3.98      4222  1182.16

The reason tilt kits are not so common is evident here, the price of PV halving in the last 4-5 years has made a big difference to the thinking of how we design systems. The only real downside to the Flat-to-roof mounted array is the winter energy is proportionally less and the summer it's  more.


Caution! Do not apply this to Off-Grid system design - the angle of the panels is much more important if you want to make maximum power through the Winter!