Smart Energy Technologies

Technical Symposium

Smart Control Interconnection Solutions for C&I Customers

Author(s)

• 

  Lucie Dupas

  Director of Engineering
  EnterSolar

AIM/OBJECTIVE:
Despite the democratization of solar, several states with no net metering policy still remain. In other cases, the grid is constrained and cannot take anymore export to avoid grid stability issues, or the costs to allow export would be too high. As a result, there are a number of instances, for financial or policy reasons, that a typical net metered system would not work. EnterSolar, in a number of projects over the last 18 months, developed mechanisms to employ smart control solutions which satisfy policy, utility and fiscal requirements.

METHODS:
Our engineering team has developed and installed several solar PV installations in specific situations where a typical net metered systems with an "uncontrolled" output would not have satisfied the utility interconnection requirements. This presentation will highlight three projects that took advantage of smart control solutions to be able to maximize the size of the PV system, while maintaining a financially beneficial solution.

In this presentation, we will explain three specific cases where software was used to solve a technical challenge that in turn made the projects pencil out financially:
- 2.5MW-DC ground mounted installation on a landfill at an industrial site, behind a dedicated substation. A fiber network with real-time curtailment software was used in addition to protective relays to ensure the system is always following the load on site while never backfeeding into the site's dedicated substation, to avoid potential upgrades to allow backfeed,
- 1MW-DC roof mounted installation on a distribution center where the state policy does not allow net metering or export onto the grid. The real time curtailment software optimizes production to never export to the grid while providing the highest possible savings to the client,
- two community solar installations totaling 1.1MW-DC over two neighboring buildings. Dynamic volt var control was implemented to ensure the grid voltage would stay within IEEE limits. Without this smart control the system size would have had to be reduced by 70%.

RESULTS:
In all three cases, we will present the problem and the method employed to solve it. We will present a simplified controls diagram and will share actual production data from each installation.

CONCLUSION:
While storage solutions can make sense in certain markets, they are not always cost effective and sometimes a PV System with a slightly lower annual specific production than typical can still pencil out, depending on market conditions. There are viable alternatives for developers and engineers looking for solutions to deploy more DG in areas of the grid where system output is constrained, either for technical or policy reasons. These low-cost solutions are typically deployed using smart inverter functions or dynamic control software.