Versatility of hydropower in comparison to thermals

While both hydropower and thermals have their advantages and disadvantages hydropower undoubtedly wins when its comes to the versatility that it serves. 

• Load control: In addition to the energy that hydroelectric plants produce they are also paid for an assortment of other utilities, namely load control. ISO-NE pays hydropower plants to vary their power output to exactly meet the load on the power grid. This is unique to hydropower because they can control how much water they let pass through the turbines at any given moment almost instantaneously, where as thermals always run at 100% and cant vary their power output.     

• Real-time market: While hydropower doesn't do as well in the day-ahead market, because they must predict when they will have water, it thrives in the real-time market. This is true for multiple reasons. 

  • Blackouts: When the grid is about to experience a blackout, especially when a large thermal trips, the price of energy is going to spike as demand begins to heavily outweigh supply. A hydroelectric plant is able to go from nothing to running at full capacity in as little as 3-5 minutes. This allows the hydroelectric plant to take advantage of the extremely high prices.  

    • ​ If a black out is to occur a hydroelectric plant requires very little energy and time to start running whereas a thermal can take 24 hours to start running again all while using an immense amount of energy that would not be available at the time.

    • A potential risk to releasing water outside of the scheduled release is having to buy the power back from ISO-NE if the dam doesn't have enough water to operate. For example if a facility manager sees the price of power spike and chooses to release the water to generate power at that higher price. They still have to produce power during the time of day they bid on in the day ahead market and if they used up too much water during the price spike and aren't able to release they will have to buy back the power they were scheduled to produce.    ​

  • Excess water: depending on the weather hydroelectric plants can be starved of water or thrive. If there is extra water a hydroelectric plant can quickly get online and utilize the water outside of its scheduled release.