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Shading....
Shading does make quite the difference... I have some both in the morning and afternoon on my array (central inverters). If I can get the graph to insert below you can see the effect in the production curve on an (essentially) cloudless day. If you look at the curve (sorry that it is upside down - TED shows production as a negative number) but the production is the light blue. You can see how the production starts in the morning (curve begins) then shade hits and it falls until about 10:45 when the last bit leaves the array and then production jumps. Then again around 3:15p it falls as the afternoon shade begins to hit until it passes at about 5p and the production jumps again (obviously a lower spike as it is later in the day). You can visualize where the curve "should" be and imagine all that lost productivity...
Prod_Graph.jpg
In the winter it is harder to see on the graph, but I have some shading that kills the bottom row of my array from trees across the street. Bottom line - it really bites into production. I knew this going into the decision so I wasn't surprised as such, but actually seeing it was still a bit of a surprise.
Anyway my point is, don't under estimate the damage shading can do to your production. With trees it likely will only get worse over the next 5-15 years as they tend to grow.
On a different topic - one argument for the microinverters has been that they have a longer life - this is great for those of us buying the systems outright, but for a lease I expect this benefits the person paying for the warranty more as the replacement of the central inverters (and production downtime) may fall on them. Had I found installers with more knowledge/comfort with microinverters when I put my array up I very likely would have opted for them. I will be looking that route when I expand my array in the next couple years.
Shading does make quite the difference... I have some both in the morning and afternoon on my array (central inverters). If I can get the graph to insert below you can see the effect in the production curve on an (essentially) cloudless day. If you look at the curve (sorry that it is upside down - TED shows production as a negative number) but the production is the light blue. You can see how the production starts in the morning (curve begins) then shade hits and it falls until about 10:45 when the last bit leaves the array and then production jumps. Then again around 3:15p it falls as the afternoon shade begins to hit until it passes at about 5p and the production jumps again (obviously a lower spike as it is later in the day). You can visualize where the curve "should" be and imagine all that lost productivity...
Prod_Graph.jpg
In the winter it is harder to see on the graph, but I have some shading that kills the bottom row of my array from trees across the street. Bottom line - it really bites into production. I knew this going into the decision so I wasn't surprised as such, but actually seeing it was still a bit of a surprise.
Anyway my point is, don't under estimate the damage shading can do to your production. With trees it likely will only get worse over the next 5-15 years as they tend to grow.
On a different topic - one argument for the microinverters has been that they have a longer life - this is great for those of us buying the systems outright, but for a lease I expect this benefits the person paying for the warranty more as the replacement of the central inverters (and production downtime) may fall on them. Had I found installers with more knowledge/comfort with microinverters when I put my array up I very likely would have opted for them. I will be looking that route when I expand my array in the next couple years.
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