Experiences with 4 x Isofoton I-110 solar panels on my slanted roof.

Time ago, in 2002, I bought 4 x Isofoton I-110 solarpanel. These I installed myself on the roof and connected these to the grid. See below the result.

Specifics of these panels

Some specifics in a bullet list:

1. these panels are mounted with help of hooks (this is called the Jeto system). This way, the panels are a little bit above the roof, so that wind can flow behind and cool the panels, which is good for reliability and efficiency. Unfortunately I do not have experience data of how much that advantage in efficiency can be.
2. The panel specification tells these panels give a 110 Watt-peak. This I have never seen myself; the max value I have seen was 330 Watt, being a mere 82 Watt per panel.
3. Each panel has its own converter mounted at the back site of the panel itself.
   
   This has an advantage: when one of the panels has a shadow on it, it will work wit much less efficiency, but it will not impact the other panels. However, the disadvantage is big: the converters are exposed to the elements outside and will most likely wear out sooner than if these would be installed in-house. Exchange of a failed power converter is also easier when built in-house (expecting that these electronic devices will live less long than the solar cells). Putting more panels on one inverter improves the efficiency; now the power loss of the inverter is divided over the set of panels connected to it, so per panel it will be less loss.

Experiences

1. the panels keep themselves clean, which is easy and convenient. In the three years that these panels are on my roof, I have never cleaned them and they still function well.
2. an example of the energy generated, over the last 7896 hours (now being 4th of June 2006) I have generated 278,5 kWh, which is 25.8 kWh per month for the four panels together. I expect herewith to arrive at 320 kWh per year, equivalent to 80 kWh per panel per year.
3. It is very nice and stimulating to have these solar panels, and you enjoy nice weather even more! Once I have seen the meter turning back, which is a very nice feeling!