The New York State Energy Plan set an ambitious goal of generating 50% of our energy from renewable sources by 2030 as a step to achieving even higher renewable energy levels to support the State’s 2050 goal of an 80% reduction in greenhouse gas emissions. Since solar and wind power are intermittent sources, only providing power when the sun is shining or wind is blowing, there are significant challenges is moving from generating a small portion of our energy from these source to relying on them for most of our power.
Fundamentally there are three basic approaches to dealing with the intermittency problem of renewable energy. The first, which we have taken historically, is to have full fossil fuel backup for the times that the renewable sources are not generating and people need electricity. In this approach the renewables are an overlay to the existing grid acting as a preferred, but redundant source of energy. This is clearly a very inefficient option since fossil fuel plants and other grid infrastructure must be maintained and possibly even increased to support the added renewables. Further, this approach cannot reach very high renewable goals since it perpetuates conventional electricity generation for a large portion of our electricity usage.
The second approach is to change electricity consumption to align with the renewable generation. In this approach devices using electricity become smarter and, through a mixture of market signals and other incentives, time the power draw to coincide with renewable energy production. Examples are shifting the time when a washing machine runs or when an electric vehicle charges. These types of efforts, including a category called demand response programs, are important tools in mitigating grid overload situations. It is likely that this type of active load management will be an important part of the electricity grid of the future; however, alone this approach eventually has diminishing returns and fundamental limitations. Some loads are easy to timeshift, but most are not.
The third approach is to store the energy produced by renewables for use at a later time when it is needed. The combination of batteries and other energy storage devices with renewables allow the renewable energy to be used at any time and, potentially, fulfill all energy needs.Incorporating energy storage into the electricity grid creates numerous other benefits including: smoothing rapid power fluctuations from renewables (for instance when clouds momentarily shadow solar panels), providing resiliency in times of storms and natural disasters, and reducing costly peak loads on the system.
The path to 50% renewable power in fifteen years may be as important as the achievement of the goal itself. Heavy reliance on redundant fossil fuel backup or load shifting over the next few years will put us on a trajectory that is fundamentally limited whereas transitioning to employ energy storage and appropriate load shifting will enable both the 50% goal and even higher levels in the future.
Written By: Dr. William Acker, Executive Director, NY-BEST