Residential PV Solar system size Calculation
Manual System Sizing
Tool
Using the amount monthly kWhs from
your utility bill, and the amount of sun hours your location receives, you can
find the size of your system, in DC watts, needed to cover 100% of your usage.
Sun Hours
Monthly Usage |
< 3.0
|
3.5
|
4.0
|
4.5
|
5.0
|
5.5
|
6.0
|
6.5
|
50kWh
|
0.7kw
|
0.6kw
|
0.5kw
|
0.5kw
|
0.4kw
|
0.4kw
|
0.3kw
|
0.
kw
|
100kWh
|
1.4kw
|
1.2kw
|
1.0kw
|
0.9kw
|
0.8kw
|
0.8kw
|
0.7kw
|
0.6kw
|
150kWh
|
2.0kw
|
1.7kw
|
1.5kw
|
1.4kw
|
1.2kw
|
1.2kw
|
1.0kw
|
0.9kw
|
200kWh
|
2.7kw
|
2.3
kw
|
2.0kw
|
1.8kw
|
1.6kw
|
1.6kw
|
1.4kw
|
1.2kw
|
250kWh
|
3.4kw
|
2.9kw
|
2.5kw
|
2.3kw
|
2.0kw
|
2.0kw
|
1.7kw
|
1.6kw
|
300kWh
|
4.1kw
|
3.5kw
|
3.0kw
|
2.7kw
|
2.4kw
|
2.4kw
|
2.0kw
|
1.9kw
|
350kWh
|
4.7kw
|
4.1kw
|
3.5kw
|
3.2kw
|
2.8kw
|
2.8kw
|
2.4kw
|
2.2kw
|
400kWh
|
5.4kw
|
4.6kw
|
4.1kw
|
3.6kw
|
3.2kw
|
3.2kw
|
2.7kw
|
2.5kw
|
450kWh
|
6.1kw
|
5.2kw
|
4.6kw
|
4.1kw
|
3.6kw
|
3.6kw
|
3.0kw
|
2.8kw
|
500kWh
|
6.8kw
|
5.8kw
|
5.1kw
|
4.5kw
|
4.1kw
|
4.1kw
|
3.4kw
|
3.1kw
|
550kWh
|
7.4kw
|
6.4kw
|
5.6kw
|
5.0kw
|
4.5kw
|
4.5kw
|
3.7kw
|
3.4kw
|
600kWh
|
8.1kw
|
6.9kw
|
6.1kw
|
5.4kw
|
4.9kw
|
4.9kw
|
4.1kw
|
3.7kw
|
650kWh
|
8.8kw
|
7.5kw
|
6.6kw
|
5.9kw
|
5.3kw
|
5.3kw
|
4.4kw
|
4.1kw
|
700kWh
|
9.5kw
|
8.1kw
|
7.1kw
|
6.3kw
|
5.7kw
|
5.7kw
|
4.7kw
|
4.4kw
|
750kWh
|
10.1kw
|
8.7kw
|
7.6kw
|
6.8kw
|
6.1kw
|
6.1kw
|
5.1kw
|
4.7kw
|
800kWh
|
10.8kw
|
9.3kw
|
8.1kw
|
7.2kw
|
6.5kw
|
6.5kw
|
5.4kw
|
5.0kw
|
850kWh
|
11.5kw
|
9.8kw
|
8.6kw
|
7.7kw
|
6.9kw
|
6.9kw
|
5.7kw
|
5.3kw
|
900kWh
|
12.2kw
|
10.4kw
|
9.1kw
|
8.1kw
|
7.3kw
|
7.3kw
|
6.1kw
|
5.6kw
|
950kWh
|
12.8kw
|
11.0kw
|
9.6kw
|
8.6kw
|
7.7kw
|
7.7kw
|
6.4kw
|
5.9kw
|
1000kWh
|
13.5kw
|
11.6kw
|
10.1kw
|
9.0kw
|
8.1kw
|
8.1kw
|
6.8kw
|
6.2kw
|
1050kWh
|
14.2kw
|
12.2kw
|
10.6kw
|
9.5kw
|
8.5kw
|
8.5kw
|
7.1kw
|
6.5kw
|
1100kWh
|
14.9kw
|
12.7kw
|
11.1kw
|
9.9kw
|
8.9kw
|
8.9kw
|
7.4kw
|
6.9kw
|
1150kWh
|
15.5kw
|
13.3kw
|
11.6kw
|
10.4kw
|
9.3kw
|
9.3kw
|
7.8kw
|
7.2kw
|
1200kWh
|
16.2kw
|
13.9kw
|
12.2kw
|
10.8kw
|
9.7kw
|
9.7kw
|
8.1kw
|
7.5kw
|
1250kWh
|
16.9kw
|
14.5kw
|
12.7kw
|
11.3kw
|
10.1kw
|
10.1kw
|
8.4kw
|
7.8kw
|
1300kWh
|
17.6kw
|
15.0kw
|
13.2kw
|
11.7kw
|
10.5kw
|
10.5kw
|
8.8kw
|
8.1kw
|
1350kWh
|
18.2kw
|
15.6kw
|
13.7kw
|
12.2kw
|
10.9
kw
|
10.9kw
|
9.1kw
|
8.4kw
|
1400kWh
|
18.9kw
|
16.2kw
|
14.2kw
|
12.6kw
|
11.3kw
|
11.3kw
|
9.5kw
|
8.7kw
|
1450kWh
|
19.6kw
|
16.8kw
|
14.
kw
|
13.1kw
|
11.7kw
|
11.7kw
|
9.8kw
|
9.0kw
|
1500kWh
|
20.3kw
|
17.4kw
|
15.2kw
|
13.5kw
|
12.2kw
|
12.2kw
|
10.1kw
|
9.3kw
|
1550kWh
|
20.9kw
|
17.9kw
|
15.7kw
|
14.0kw
|
12.6kw
|
12.6kw
|
10.5kw
|
9.7kw
|