Wherever or however an EMP comes from, depending on the size of it, the effect on electrical and electronic equipment is devastating, basically destroying it.
The solar cells themselves are in fact semi-conductor device, that is, it’s basically a P-N junction and so will be affected. However, scientists estimate that the actual production capacity of solar panel would only reduce by up to 10%, which is encouraging.
Now for the bad news – depending on the EMP proximity, the electronic control equipment and associated cabling would most probably be fried.