Navigant Research Blog

Energy Storage to Optimize and Advance CHP Generators

— August 31, 2017

Energy storage is often associated only with the integration of renewable energy. However, recent market developments have highlighted the potential for storage to optimize both existing and new fossil fueled generators. While large-scale pumped hydro energy storage has been used on the grid for decades, those systems were rarely tied directly to any generation plants. A recent storage project built by General Electric in California is evidence that the falling costs for battery storage are opening opportunities to improve the efficiency and flexibility of existing generators.

There are attractive advantages for energy storage to optimize generators at a smaller scale. Gas-powered combined heat and power (CHP) systems are becoming increasingly popular due to the improved efficiency these systems offer customers that need a reliable supply of both heat and electricity. Because of the varying energy needs of these customers and the dynamics of CHP systems operation, there is frequently an overgeneration of either electricity or heat. This energy is often wasted, as establishing contracts that export excess energy is costly and challenging. Both thermal and electrical energy storage systems can greatly reduce wasted energy when tied to CHP systems and can provide attractive ROI for customers.

Industry Actions

Several recent acquisitions in the industry have emphasized this dynamic. In a recent blog, my colleague Adam Forni discusses these developments and the efforts of generator manufacturers to expand their offerings and participate in the emerging Energy Cloud. Notable recent investments in storage providers include Wärtsilä’s purchase of Greensmith and Aggreko’s acquisition of Younicos.

In both cases, incumbent generator providers moved to acquire storage companies focused on the software and controls required to optimize storage systems and integrate them into electricity markets. These tie-ups are mutually beneficial, as the storage providers gain access to new sales channels and potential new customers. The generator providers are likely focusing on developing the capabilities to integrate storage into their offerings and utilize new combined solutions to provide energy and capacity services in competitive electricity markets. The additional revenue generated by these grid services can greatly improve the overall economics of new storage and microgrid projects, including those that expand the capabilities of existing generators.

Into the Future  

The move toward microgrids and local power systems to improve the resilience of energy supply is an important driver for the integration of energy storage with conventional generators. Navigant Research’s recent Market Data: Combined Heat and Power in Microgrids report anticipates that 11.3 GW of new CHP capacity will be added in microgrids around the world over the next decade. The addition of these systems presents a major opportunity for both thermal and electrical energy storage to improve overall efficiency. Through the integration of energy storage and the sophisticated software platforms used to connect to energy markets, large amounts of new distributed energy capacity will become available on the grid.


Tesla and Storage Industry Take Up Another Challenge to Strengthen the Grid

— August 3, 2017

In September 2016, the massive blackout that hit South Australia cut electrical service to roughly half of the state’s 1.7 million residents for anywhere from 4 to 48 hours, putting grid reliability and renewable energy in the spotlight. Following that event, Tesla CEO Elon Musk claimed that large-scale energy storage could have prevented the disaster, promising that his company could build 100 MW of energy storage in just 100 days or it would be free. While this was seen by many as an attempt to get energy storage in the conversation about grid upgrades, it has now been announced that Tesla won a competitive solicitation to build a 100 MW storage facility.

Tesla’s new project will be located at the Hornsdale Wind Farm currently being built by French firm Neoen. The project will have a 100 MW power output with 129 MWh of storage capacity using Tesla’s lithium ion Powerpacks. The system will be used to smooth the output of the wind farm, shift energy to align with grid demand, and provide reserve capacity for the grid that could theoretically prevent future blackouts as both a source of system inertia and system restart services (in other words, a blackstart).

Major Challenges

Tesla faces some major challenges to build this project in such a short period. If successfully operational within 100 days, it would be one of the few 100 MWh-scale storage systems in the world commissioned in less than 4 months. These records were recently set last year when several large storage projects were built in response to California’s Aliso Canyon natural gas leak to provide emergency reserve capacity.

The key challenges noted by companies that developed the Aliso Canyon response projects involved supply chain and logistics and the overall orchestration/coordination of the project. However, Tesla may have advantages in logistics, as it is a vertically integrated provider of battery systems, which will reduce the time required to order both batteries and balance of system components. Given its recent expansion of manufacturing capacity, it is possible that the company already has many of the modular Powerpack systems built and ready to ship to support this project.

Once the batteries and all necessary components have arrived onsite, the coordination of such a large and complex engineering project is no small feat. Few projects of this scale and type have been built. As with many large storage projects, the experience is a first for local contractors providing engineering and construction work, which can delay the process.

Major Impact

If the project is successfully developed on time, it will represent another milestone, proving the maturity of the energy storage industry. The relatively short timeframe needed to build new large-scale storage projects gives the technology a major advantage over alternatives such as thermal power plants and transmission and distribution infrastructure. A shorter development period allows for shorter planning cycles for utilities, allowing them to quickly respond to changing grid conditions.

This project represents the first major competitive win for Tesla’s large-scale storage business in the Australian market. However, Tesla is not alone in developing massive storage plants in Australia. The Lyon Group recently announced its third solar plus storage project in the country, bringing its total pipeline of projects in development to 640 MWh. However, many stakeholders still question the economic viability of these storage projects, and regulatory rules are still evolving in Australia and other markets around the world. Despite the concerns, these projects are evidence that energy storage is starting to play a major role in the global electricity industry, with large-scale projects able to solve grid issues faster than conventional systems.


Can California Wield Energy Storage to Grid’s Advantage?

— July 25, 2017

The California Public Utilities Commission has proposed a ruling that could require thousands of energy storage projects to be more responsive to the dynamic grid as the state continues to grapple with integrating intermittent renewables. The ruling would apply to projects funded by the Self-Generation Incentive Program (SGIP), which underwent a major overhaul this year in a bid to grow energy storage.

In the theme of continual refinement, the ruling proposes to improve projects’ grid support, one of the three key policy goals of SGIP. It would require systems to operate under dynamic tariffs like critical peak pricing or time of use (TOU) or participate as an aggregated demand response or distributed energy resources (DER) product that is bid into the California Independent System Operator’s (CAISO’s) wholesale markets. The goal is to make DER more reactive to real-time changes on the electric grid. The effect on the California’s storage market could be significant, with SGIP likely supporting most of the state’s gigawatt-sized industry through 2020.

Industry Weighs In

The ruling requested comments from all interested parties. Utilities, vendors, and others have weighed in, revealing some key themes:

  • Storage revenue predictability impacts: Many storage deployments primarily monetize by demand charge management, a practice that could become more complex under the new rules. As storage revenue streams continue to be a moving target, this ruling could add complexity to vendors attempting to reliably model the profitability of their projects.
  • Some customers are ineligible: For example, community choice aggregator and direct access customers don’t have access to all the programs and tariffs available to investor-owned utility (IOU) customers. Regarding aggregation in the CAISO market, commentators noted that, while there is a great deal of promise, stakeholder engagement is still in early phases, which could present hurdles to broad adoption.
  • Challenges with existing tariffs: Some expressed concern that existing tariffs and programs may not directly align with SGIP goals. For example, certain TOU customers are guaranteed grandfathered TOU time periods for up to 10 years, which may or may not incentivize battery storage operations to align with SGIP.

New Regulatory Constructs Needed

Many opined that new tariffs or programs are needed to truly get storage systems to align with grid priorities (and carbon emissions mitigation, another of SGIP’s goals). Some predicate their position on whether new TOU rates are rolled out effectively. Others point out that aggregation of storage into virtual power plants may get easier as more DER providers gain approval. And toward the goal of limiting emissions, integrating real-time marginal grid emissions into tariffs would be a major step toward fulfilling SGIPs (and the state’s) carbon emission reduction goals. To that end, companies like the non-profit WattTime are pushing to make such real-time data available, actionable, and ready to implement into tariffs.

The outcome of this ruling remains to be seen, as comments are still being considered. However, one thing is clear: California will continue to push for aggressive integration and aggregation of responsive DER in its quest to develop an advanced and distributed electric grid.


Saving the Sun for Later: Opportunities and Barriers for Solar PV plus Energy Storage

— June 22, 2017

At the recent Better Buildings Summit, I had the opportunity to moderate a session with Karen Butterfield of Stem, Ben Myers of Boston Properties, and Jessie Denver with the City of San Francisco to discuss their strategies and experiences related to adopting solar PV plus energy storage. It was a spirited discussion and we received in-depth, informed questions from the audience on feasibility, system costs, lessons learned, and how to make the business case for project deployments.

Lessons Learned

Stem opened the session and provided many great lessons learned from its experience to date:

  • Solar PV plus energy storage can be applied to save energy costs and demand charges, but a concise site- and tariff-specific use case is required to make a project work.
  • Robust software is required to integrate building load, solar PV system performance, and battery deployment scenarios to generate cost savings.
  • Utility partnerships can improve project economics and help make the business case.

Boston Properties highlighted that, as part of its sustainability plan, it has installed solar PV at many of its properties across the United States and has reduced its energy charges. The company is now looking at solar PV plus energy storage to guarantee tariff-specific demand charges as well. While Boston Properties has yet to complete a project, it is in the process of negotiating contracts using a solar PV plus energy storage power purchase agreement with a shared demand charge savings component.

Whereas Boston Properties’ drivers were financial and sustainability, the City of San Francisco’s drivers are resilience and sustainability. The city recently won a US Department of Energy SunShot grant to study the feasibility of installing solar PV plus energy storage at critical facilities to provide power in case of an earthquake or another emergency. San Francisco is currently selecting pilot sites and completing its feasibility analysis. As part of the project, the city and its project partners have created a free online tool to help others assess the feasibility of using solar PV plus energy storage for resilience.

Growth of Distributed Solar PV plus Energy Storage

The topics and session discussion at the Better Buildings Summit highlighted several key issues that Navigant sees as important for the growth of distributed solar PV plus energy storage markets:

  • The ability of energy storage software platforms to forecast energy and demand charge savings for anticipated building load and battery deployment scenarios is critical to the business case for these projects.
  • The multitude of regulations and rate structures affecting both solar and energy storage, and their expected evolutions, will increase the value of project design and operating software by helping lower customer acquisition and development costs.
  • As with standalone energy storage deployments, the predictability of costs savings from these projects will further the development of financing innovation to drive the deployment of these technologies.
  • The value of resilience and resulting business case criteria will differ greatly between solar PV plus energy storage customers. For example, the resilience value of solar PV plus energy storage for commercial office building occupants differs from that for a municipality like the City of San Francisco. Building occupants likely have a business continuity plan to address long-term energy outages at their facilities while the city is charged with critical first responder responsibilities in the event of a disaster or emergency.

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