Solar + Storage for Manufacturers


Massachusetts Clean Energy Center allocated $150,000 for “The Solar Plus Storage Pilot Program”, as recommended in The State of Charge report. The Solar Plus Storage funding opportunity was released June 8, 2016 and closed July 10, 2016. The objective of the program was to retain qualified firms to perform site assessments that evaluate and quantify the technical and financial viability of installing solar plus energy storage systems OR energy storage systems only in small-to-medium manufacturing/industrial facilities in Massachusetts. While the study results were somewhat mixed, many manufacturing sites across a variety of sectors and utility territories, could realize substantial savings from installing solar plus storage systems in their facility.

Five consultants were selected to conduct the studies, and to demonstrate how different modelling approaches might produce different outcomes. The selected consultants, consisting of Alevo, Customized Energy Solutions, Energy and Resource Solutions, General Electric, and GreenCharge, gathered facility specific information and energy data, conducted their analyses, and communicated their findings to facility owners and to MassCEC. A presentation summarizing the findings can be found here. The Solar + Storage one-pager can be found here.


Consultant Workflow

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Methodology of Studies

Each consultant used customized modelling tools to analyze manufacturing site load data assigned to them and optimize solar plus storage systems for each site. 


Customized Energy Solutions (CES): CES used a proprietary modeling suite, CoMETS.  CoMETS used load data, utility tariff information, and system configuration to examine each hour in a year that solar plus storage will be used to optimize usage. Solar plus storage sizes run through CoMETS in increments of 100kW. Optimal services for solar plus storage configuration were determined for each hour in CoMETS. The annual revenue and NPV calculations were based on configuration, with the highest NPV chosen. The incentive captured in this model was FITC. Five sites were successfully analyzed with this tool. The full report can be viewed here.


General Electric: GE used Distributed Energy Resources – Customer Adoption Model (DER-CAM) and PVWatts to analyze their assigned sites. Specifically, DER-CAM was used to estimate optimal solar plus storage sizing for each facility. PV generation was estimated for each facility using NREL’s PVWatts tool. Three sites were successfully analyzed with this tool. GE also used DER-CAM for financial modeling of solar plus storage. Incentives such as FITC and MARCS were included in the financial analysis, but SRECS and SMART were not built into the analysis. The full report can be viewed here.


GreenCharge: GreenCharge used their proprietary platform GridSynergy Analytics to analyze their site. GridSynergy integrates real time feedback and simulates imperfect conditions for analysis. Of the sites assigned to GreenCharge, only one site was eligible for full analysis. The financial model aggregates utility bill optimization, DER generation patterns, and market aggregation for facility analysis. The financial model also considers incentives such as FITC and SMART which are crucial for the addition of solar and storage to be financially viable. The full report can be viewed here.


Energy and Resource Solutions: ERS used their proprietary DER model for analysis of their assigned facilities. DER tool was used to determine the most cost-effective solution for each site. The building’s historical electrical data, along with NREL, who was used to simulate the weather, calculated the hourly effects of the installed system. Seven sites were successfully analyzed. The financial model calculates maximum savings from generation of kW and reduction of peak kW demand. Incentives such as SRECs were used in analysis. The full report can be viewed here.

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                                                                                                                                                                                                        Ideal Customer Profile


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Barriers Identified

Interval Data Availability: Collecting load data can be difficult for facility managers and small facilities because they often lack access to interval data. Further, 15-minute interval data is necessary to make decisions on solar plus storage.

ICAP Predictions: The ability to reduce ICAP charges are not certain and not always a separate line item in an electricity bill.

Frequency Regulation Market: Frequency regulation market is relatively small and dominated by large hydro resources. The minimum size for energy storage is 1 MW.

Hardware Tariffs: New tariffs could increase prices for solar systems.

Incentives: There is currently a lack of standalone energy storage incentives.

Demand rates: Demand rates need to be adjusted for battery storage to be financially attractive.


Opportunities Identified

High Utility Tariffs: At the time of analysis, Eversource was increasing demand charges.

ISO-NE Market Revenue Streams: Energy storage is more efficient in providing ancillary services than other technologies, so ISO-NE may offer more incentives in the future.

Cost Reductions: Based on ES cost reduction assumptions, $11/kW/month may be new minimum demand charge (currently ~$15/kW/month) by 2021.

Incentives: FITC and SMART incentives.

Volatile Load Profile: Energy storage has the ability to balance volatile load profiles by “chopping off” peaks.

Narrow Demand Windows: This would allow for smaller systems to be more impactful.

Time of Use Rates: This would encourage battery charging in the evening and discharge at peak.


Table of Results

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Non-Monetizable Benefits

Wholesale Market Cost Reduction: When used in demand response, it reduces start-ups and shut-downs of fossil fuel generation.

Energy Cost Reduction: Reduces demand on electric system, and therefore the LMP.

Integrating Distributed Renewable Generation: Helps integrate more renewables into the grid.

T&D Cost Reduction: Reduces stress and can defer distribution or substation investment.

Emissions: Reduces GHGs.

Resiliency: Contributing to a quick recovery from any outages.

Frequency Regulation: Helps maintain the proper frequency of the grid.

Voltage Support: Support the maintenance of constant voltage.

Black Start: Be the first to energize the grid after blackout.

Reserve Capacity: An instantaneous response to ease the burden on spinning reserves.

Ramping Loads: Helps dampen rapid changes in generation from variable sources such as solar and wind.


Common Recommendations

Online Tools: Support creation of an online tool with simple inputs/outputs that can help facility managers make informed decision on solar + storage. Include various project financing and ownership models as well.

Interval Metering: Expand efforts to increase proliferation of interval meters for smaller manufacturing customers in MA (<20% currently have them now).

Co-location: Energy storage alone is not financially viable. It needs to be co-located with solar PV.


Additional Conclusions

  • CES & GE both predicted an average payback period of 5 – 6.4 years for an optimal sizing of solar and storage.
  • Installing ES without interval data is too high risk due to its dependency on load profile.
  • Battery Duration:
    • 30 minutes is sufficient for frequency regulation.
    • 1 hour+ is best for ICAP charge management.
    • Longer duration systems participate more in demand charge management and less in frequency regulation.

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