The Advantages of Adding Storage to Your Commercial Solar PV Design

In the article below, Christopher LaForge, IREC-Certified Master Trainer, NABCEP-Certified PV Installation Professional, and CEO of Great Northern Solar, provides detail about the advantages of adding storage to your commercial solar PV design.

Learning Takeaways:

1. By storing solar generation during the middle of the day and then using the stored solar generation at the end of the day a business can achieve a flat level of demand for the day.
2. Stationary storage does not have to link with renewable energy. It can flatten peaks of electricity demand, which could lead to less reliance on conventional generation power plants.
3. In addition to avoiding peak demand charges, “intelligent systems” will have the potential to create effective micro-grids and other exciting demand-side controls for commercial clients. 
4. Small utilities that do not own their own generation facilities are looking into the benefits of commercial solar PV with intelligent storage to improve their bottom lines.
5. Utilities are looking to these type of systems to manage on-site power generation and consumption in ways that could allow them to avoid investments in grid infrastructure.

With the dramatic reductions in the cost of solar PV systems, a significant opportunity is being raised by several manufacturers of “intelligent storage.”

“Intelligent storage” is advanced behind-the-meter energy storage that uses predictive analytics to provide rapid response to spikes in commercial customers’ electricity demand, drawing on previously stored power to reduce energy costs.

Commercial utility rates often include demand charges. As a commercial utility client, when you go over a certain amount of load during a billing cycle—even for a short period of time—you get a demand charge that is based on that peak draw from the grid. 

By storing solar energy generated during the middle of the day and then using it at the end of the day, a business can achieve a flat level of demand for the day. The reduced cost of storage and the development of solar PV combined with intelligent storage may allow for systems that more than offset the additional cost of including battery storage.

Jonathan Bass, SolarCity’s vice president of marketing, said “… that from a limited launch in California, Connecticut and Massachusetts, regions of the US where demand charges are typically higher, (PV and storage) is becoming economical in more and more places.” Bass indicates that Solar City’s product— DemandLogic—“tends to be most attractive for customers that are getting hit with exorbitant demand charges…” (1)

Elon Musk broadened the discussion by indicating that stationary storage does not have to be linked with renewable energy.  He highlighted the possible network benefits of “system-wide implementation” of energy storage, including flattening peaks of electricity demand which could lead to far less conventional generation power plants being required – “you can basically, in principle, shut down half of the world’s power plants if you had stationary storage,” Musk said. (2)

Companies like Stem, Green Charge Networks, and Coda Energy are offering behind-the-meter energy storage systems for commercial buildings. Other large players such as Gexpro (the former GE Supply distribution business bought by French electronics wholesaler Rexel) see behind-the-meter battery systems becoming just another piece of a broader building product portfolio. Gexpro is bundling lithium-ion batteries from South Korea’s LG Chem and bidirectional inverters from Texas-based Ideal Power in its new battery energy storage solution (BESS). (3)

Growing Energy Labs, Inc. (Geli) is providing the energy storage management software for this and several other commercial storage projects. “I want thousands of little businesses popping up to own and operate, essentially, micro-utilities, with energy storage systems,” Geli CEO Ryan Wartena said in an interview. “Backing into that is a lot of data analysis. We right now have analyzed over 300 different facilities for demand-charge management, microgrid, and storage with solar, and with load control aspects as well.”

“That analysis is the basis of what’s used for financing,” he said. “We go ahead and make models for performance, financials, and health of the system—and we’re able to fit those models directly into our energy control software. And we run a service, as part of our annual maintenance, of what’s essentially back-end validation.” (4)

This kind of kind of life-cycle analysis is what can stop the financing of projects if it does not provide the confidence necessary to satisfy underwriters. The systems will have to perform 100% of the time with adequate prediction and intervention on energy use spikes to fully avoid peak demand charges and have the systems pay for themselves.

In addition to avoiding peak demand charges these systems will have the potential for creating effective micro-grids and other exciting demand side controls for commercial clients. 

New York and California utilities are looking to these type of systems to manage on-site power generation and consumption in ways that could allow them to avoid investments in grid infrastructure, which is becoming an important part of new regulatory frameworks being developed in both states.

Finally, small utilities that do not own their own generation facilities are looking into the benefits of commercial solar PV with intelligent storage to improve their bottom lines. These utilities face the same types of rate structures from the larger utilities that they purchase energy from and can therefore use these systems for noticeable benefits.

All in all, the world of renewable energy deployment has become notably stronger and broader through the development of intelligent storage. The addition of the Tesla Gigafactory, which claims that it will double the world’s production of lithium-ion batteries, appears to be opening a whole new cost-structure for implementing storage into solar PV systems.

Sources: 1) PV Tech Storage News – SolarCity: Storage can drive down commercial solar costs in US – By Andy Colthorpe Apr 23, 2015

2) PV Tech Storage News – Tesla hints at further Gigafactory ramp up, consulting with utilities on storage dispatch controls – By Andy Colthorpe Aug 07, 2015

3) & 4) – Greentech Media – Behind-the-Meter Energy Storage Goes Wholesale – Gexpro, LG Chem, Ideal Power and Geli launch commercial building batteries as a package. By Jeff St. John May 4, 2015

Additional Resources

• Free Lecture: Battery Capacity – The Basis of Storage
• Free Tool: Load Calculator for Battery Based Solar Projects 
• Online Course (12 Advanced NABCEP Hours): Batteries in Solar PV Systems: This 6-week course provides in-depth analysis of the issues surrounding the use of batteries for PV applications. It covers battery design, specification, use, and maintenance.
• Online Course (16 Advanced NABCEP Hours): Commercial Solar PV Design