Niteesh Shanbog : Usually, there are power purchase agreements in place. For instance, if the seller makes money by selling power, there might be penalties on the seller for not being able to sell agreed amount of power. The weather conditions and "unforseen issues" should be mitigated by either using a highly accurate forecasting technique (like numerical weather prediction) or using appropriate amount of storage at the sellers' end.

The above answer is good. But, the first thing first is the imbalance of demand and supply, which reduces the system reliability. In this case, the consumers will experience on outage, moreover in this modern days electricity is must, all disadvantages is in consumers side, and penalty is only impact to the seller.

There are two aspects to be considered: technical and commercial.

From the technical perspective, there will be a power imbalance. If the microgrid is connected to the bulk grid (distribution system from an utility), power will be imported from the utility until the system gets balanced again. If the microgrid is islanded, then the grid frequency will drop. In that case, if the frequency drop goes below 2%, then load shedding will typically happen until consumption and generation is matched again. If that does not happen quickly enough, the system might collapse.

Now to the commercial perspective. If the microgrid is importing power from the utility, consequences vary from place to place. But usually the microgrid owner(s) might:

1) pay the normal grid tariff ($/MWh) for the power they are importing, or/and;

2) pay an additional tariff ($/MWh) for using power above the limit contracted, or/and;

3) pay a lumpsum penalty ($ for each event) for using non-contracted power.

In summary, this is what happens. The nuances are more complicated, of course.

https://www.researchgate.net/publication/260432036_Bioenergy_A_sustainable_Energy_Option_for_Rural_India

https://www.researchgate.net/publication/318984196_Hotspots_of_Solar_Potential_in_India

https://www.researchgate.net/publication/230822079_Regional_Bioenergy_Planning_for_Sustainability_in_Himachal_Pradesh_India