Solar Photovoltaic cells,modules are rated for 1000W/m2, AM1.5global and 250 c cell temperature. the performance of the cell/module vary proportionately for incoming solar radiation intensity.
I suspect the answer to your question will be "it depends".
Having said that, I will follow with interest this topic as someone might have some quantitative answer.
Unfortunately I am not able to help directly too much but I am actually thanks you for posing this question. There is just one think that I could suggest - perhaps you could check where are placed the northers (or southeast) PV solar park and then check the minimum, average and maximum solar radiation in those areas. There is an avalable list in Wikipedia (Canada has at least a large PV solar park in the south of the country).
I suspect the answer to your question will be "it depends".
Having said that, I will follow with interest this topic as someone might have some quantitative answer.
Unfortunately I am not able to help directly too much but I am actually thanks you for posing this question. There is just one think that I could suggest - perhaps you could check where are placed the northers (or southeast) PV solar park and then check the minimum, average and maximum solar radiation in those areas. There is an avalable list in Wikipedia (Canada has at least a large PV solar park in the south of the country).
I do not think there is a minimum irradiation or temperature which is necessary to operate PV panels. However, there is a temperature effect which comes into play. As the irradiation increases, there is a tendency for the ambient temperature to increase too. PV cells' performances are affected by temperature because the dark current density produced by the cell has a strong temperature dependence. The performance drops with increase in temperature for instance, for a polycrystalline PV cell, if the temperature decreases by 1oC, the voltage developed increases by 0.12V. The PV cells are specified at NOCT of 25oC at 1000 W/m2 but in some environments, the cells can reach a temperature in excess of 90oC. This seriously affects the output. I hope this will be of help.
It depends on PV project site (location weather condition) and system structure (inverter/module). Perhapes you would try simulation software (eg. PVSyst) to get brief system performance for specific project site and system structure.
As many of the researchers have suggested, it depends on the type of the PV panel. If you take the silicon PV cell panels, which are not efficient totally depends on the amount of irradiation available on a given area. As the resource is lower, at some point the panels stop generating power and you can say that point is the minimum range of the resource. But remember this value is not fixed for all PV cell types and for all places. If you take a more efficient PV like Nano Solar paint, they produce power at very minimum irradiation.
solar cell not depend upon the temperature at high temperature its quality and efficiency get lower. its depend upon irradiance value under standard solar cell efficiency reach up to 31% if irradiance reach to 1000 watt/m2 at 1.5AM.
If one can use micro-inverter or DC DC converters, it is possible to extract even 1 W of power from PV panels with 60 cells (I am referring to m-Si). However the inclined global irradiation should be around 50 W /m2.