Capturing distribution grid-integrated solar variability and uncertainty using microgrids

Abstract

The variable nature of the solar generation and the inherent uncertainty in solar generation forecasts are two challenging issues for utility grids, especially as the distribution grid integrated solar generation proliferates. This paper offers to utilize microgrids as local solutions for mitigating these negative drawbacks and helping the utility grid in hosting a higher penetration of solar generation. A microgrid optimal scheduling model based on robust optimization is developed to capture solar generation variability and uncertainty. Numerical simulations on a test feeder indicate the effectiveness of the proposed model.

Microgrid Value of Ramping

“…Furthermore, the microgrid optimal schedule is changed as microgrid sells less power in the afternoon and evening hours, which means a smaller revenue for the microgrid. The difference of microgrid operation cost in these two cases can be used to find the value of ramping, as in (29), which in this case is calculated as $10.4/MWh. This is the minimum price that should be offered to the microgrid in order to maintain 2 MW reserve ramping in all operation hours within a one-year scheduling horizon.…”

“…By leveraging potential flexibility of existing microgrids, viable schemes for addressing the challenging issue of renewable generation integration and supporting distribution grid flexibility are proposed and investigated in [27]- [29]. However, lacking is the proper valuation mechanism that determines the microgrid value of ramping and enables participation in a distribution market or utility support programs.…”

Distribution Market as a Ramping Aggregator for Grid Flexibility Support

“…Microgrids have been already proposed as a flexibility resource for increasing the flexibility of the power system and supporting the utility grid to capture the utility ramping, variabilities, and uncertainties [20]- [22]. In line with demand bidding, microgrids can submit their ramping capability to the DMO at each hour.…”

“…This model is expanded on the basis of coordinating microgrid net load with aggregated consumers/prosumers net load, while taking both inter-hour and intra-hour net load variabilities into account. Recently, the variability and uncertainty natures of solar generation are captured by utilizing microgrids [22]. The conclusions drawn from these research efforts advocate that power system operators can considerably take advantage of microgrids to provide flexibility in distribution networks to address the flexibility-associated bottlenecks.…”