Utilities have long known that renewables will impact the grid, but have yet to define and quantify the impact in any usable way. In this report, we define intermittency and determine the optimal mix of baseload and flexible generation coupled with emerging technologies required to integrate more than 30% wind and solar generation into grid. Emerging automated demand response programs are the lowest cost option, but are limited to being capable of managing only the highest 2% of demand. At current natural gas prices, electricity can be generated by natural gas power plants cheaper than it can be stored and shifted by any grid storage technology. However, unbridled natural gas use with 30% renewables and no storage will unavoidably result in the curtailment of renewably generated electricity. To minimize curtailment, utilities will have to install enough grid storage to capture and shift at least 0.5% of the total electricity generated over the course of the year.