What’s the Concept?
All operating power plants possess “interconnection” rights to electrically connect to and inject electricity into the transmission grid. Often securing those rights has taken several years, required millions of dollars to upgrade the transmission system and required power plant developers to take on significant development risk. Securing new interconnection rights is arguably the riskiest part of the greenfield power plant development process.
Despite the time, cost and risk associated with securing the interconnection rights, some power plants - in particular wind farms - grossly underutilize the interconnection rights that have been secured. For example, a 100 MW wind farm that has secured 100 MW of interconnection rights will - on average - use only 20% to 50% of its interconnection rights given the inherent intermittent nature of the associated wind resource.
In 2018, FERC allowed for owner/operators of power plants to better utilize their interconnection rights by installing additional generator and/or storage capacity on the generator side of the grid connection that would take advantage of the “unused” portion of the wind farm interconnection rights (i.e., the “surplus interconnection” rights). For example, a 100 MW wind farm operating at an annual 33% capacity factor, would have - on average - 67 MW of surplus interconnection rights that could be utilized by newly installed solar and/or storage assets.
Compared to the years-long, cost-uncertain process for securing new interconnection rights for a greenfield power plant, the process for securing surplus interconnection rights is relatively straightforward and takes roughly 90 days depending on the operator of the transmission system to which the wind farm connects. Moreover, there is minimal risk with respect to the cost of surplus interconnection since the original wind farm / generator paid for transmission system upgrades to accommodate the full output of the wind farm.
In addition to maximizing the value of the interconnection rights, the addition of solar and/or storage assets to the wind farm can allow for shaping generator output to meet peak demand, arbitrage location marginal prices and provide resource adequacy. [See below for an example.]
Bird Dog seeks to help owner/operators of wind farms and other low-capacity factor generating assets take advantage of these benefits by leading the development of the solar and/or storage assets. For information click here.
Benefits of Adding Solar with and without Battery Energy Storage to an Existing Wind Farm
The following is the result of an optimization analysis demonstrating how adding solar with and without battery energy storage to an existing wind farm can materially increase power plant output when electricity is needed most without the time, expense and risk of securing new interconnection rights.
Similar optimization analysis can be performed for arbitraging location marginal energy prices and achieving other objectives.
We start by looking at the “12 x 24” output of stand-alone wind and solar power plants located in the Midwest compared to when electricity demand is at its greatest.
Next, we look at the output of a power plant that adds the solar facility to the existing wind project.
Last, a battery energy storage system is added to the wind/solar facility.
These and similar benefits (e.g., optimizing capacity-value and/or location marginal price) are achieved without the time, cost and risk or securing new interconnection rights for the solar and/or battery energy storage projects.
