GridSolar, in its Jan. 19 final report filed with the Maine Public Utilities Commission (MPUC), said that given the project success to date, the MPUC should extend the Boothbay Smart Grid Reliability Pilot project, which is the first of a larger set of non-transmission alternative (NTA) pilot projects to be developed in the Mid-Coast and Portland regions, to the full 10-year project period and authorize GridSolar to acquire additional NTA capacity if, and as, needed.
GridSolar also recommended that the MPUC proceed apace with the development of larger NTA pilot projects for the Mid-Coast and the Portland Loop regions in MPUC Docket 2011-138; incorporate these results into consideration of the need to designate a statewide Smart Grid Coordinator; and use the information in future reviews of proposed transmission lines and projects.
GridSolar noted that the MPUC has over the last decade debated the question of whether NTAs – distributed generation, efficiency, demand response, storage, and new smart grid technologies – can solve electric grid reliability needs at lower cost and with less pollution than new transmission lines or transmission system upgrades.
The MPUC in 2012 established the Boothbay Pilot to test the NTA hypothesis, GridSolar said, adding that the pilot sought to demonstrate whether a portfolio of NTAs could reduce effective load under peak conditions on specific transmission assets in the Boothbay sub-region of Central Maine Power’s (CMP) electric grid by 2 MW, thereby avoiding identified grid performance violations that would otherwise require an estimated $18m rebuild of the 34.5-kV electric line from Newcastle to Boothbay Harbor.
GridSolar said that the pilot sought to discover the availability and pricing under competitive procurement of a full range of NTAs in Maine, operational characteristics and limitations, and whether NTAs could be so used at scale in other regions of the CMP and Emera Maine grids in Maine.
GridSolar said that it was designated, under MPUC order, as the project coordinator, and it, along with CMP, jointly developed operations, measurement and verification plans, which established applicable NTA eligibility requirements and performance criteria, communications and operations protocols, legal and payment provisions, and procedures to validate and report on results.
GridSolar said that it issued in 2012 and 2013 two requests for proposals (RFPs) for NTAs, noting that the responses demonstrated healthy competition, with each solicitation exceeding bid targets and the offer prices declined over time.
RFP I, issued in September 2012, received a total of 12 bids from six separate NTA resource providers totaling nearly 4.5 MW in five NTA resource categories, including solar photovoltaic (PV). GridSolar added that RFP II, issued in May 2013, received a total 22 bids from 10 separate NTA resource providers totaling just over 4 MW in five NTA resource categories, including solar PV and efficiency.
GridSolar said that following each RFP, it submitted for review by the parties and the MPUC an evaluation of each bid, together with GridSolar’s recommendation of which NTA resources to accept, balancing cost, reliability (performance), diversity and emissions, while, in keeping with the pilot purposes, ensuring a minimum of 250 kW each of conservation and efficiency, demand response, renewable distributed generation, and back-up generation.
The accepted bids yielded a full range of NTA resources, including efficiency, PV solar, demand response, back-up generation, and energy storage, GridSolar said.
Based on reduced reliability requirements due to declining peak loads, 1.8 kW of NTAs were deployed between late 2013 through early 2015, including the first-ever large-scale (500-kW) grid-tied battery in Maine, a 500-kW diesel fueled back-up generator (BUG), 308 kW of PV solar arrays, 243 kW of efficient lighting and air conditioning, 224 kW of peak load shifting, and 29 kW of demand response units, GridSolar said.
At the same time, GridSolar said that it developed a Smart Grid Operations Center that includes a remote Command Interface system with CMP and secure digital SCADA (supervisory control and data acquisition) communications networks to interact with NTA resources in the field. The Command Interface, GridSolar noted, enables CMP to remotely see available NTA capacity, schedule testing or dispatch emergency NTA parameters, including date, time, load, duration and circuit location, and monitor dispatch and performance. The SCADA systems are then used to monitor, dispatch and control NTA resources, GridSolar said, adding that the systems will notify via alarm the GridSolar Operations Center manager and, using GridSolar programmed algorithms, define a dispatch order for needed NTA resources and provide a signal to each resource.
All actions are monitored and confirmed in real time and the data is recorded, allowing NTA performance to be compared against actual substation loads to confirm compliance with grid operational criteria, GridSolar said.
“Because the GridSolar network operates customer-side NTA assets with direction from CMP grid control systems, it is entirely complimentary to rather than duplicative of CMP’s existing grid control infrastructure,” according to GridSolar.
Testing in 2014 and 2015 demonstrated that the NTA concept works, GridSolar said, adding that the GridSolar Operations Center contacted and turned on contracted NTA resources within minutes of receiving a dispatch order from CMP, and those NTAs directly reduced upstream substation loads at levels sufficient to meet grid reliability criteria and offset the need for more expensive transmission investments.
According to GridSolar, those results demonstrate that a wide range of NTA solutions are available in Maine that can meet reliability requirements and which are both scalable and replicable in other areas of the CMP and Emera Maine electric grids.
All NTAs, individually and together, met reliability needs in the pilot area for less cost than the transmission-only solution, GridSolar said, adding that the net cost of the accepted NTAs, together with administrative and operational expenses, is projected to be less than 33% of the cost of building a new power line and will save ratepayers about $18.7m over the 10-year project life.
Even if the pilot were terminated early at the end of 2016, which GridSolar said is the worst-case scenario, it would result in net savings of $2.5m, and were it terminated at the end of 2020, the savings would be $9.2m.
The pilot has also identified the potential for NTA solutions to further reduce ratepayer costs to address identified transmission needs through growing NTA on NTA competition and because NTA project sponsors are willing and able to bear a significant portion of system costs in return for other customer benefits NTAs provide, GridSolar said.
In comparison to the transmission system upgrade alternative, the NTA solutions also result in net reductions in energy use, greater use of renewable energy sources, lower emissions and reductions in fossil fuel consumption, GridSolar said.
GridSolar further noted that as the NTAs are predominantly located at customer sites, the NTA solution results in, for instance, enhanced customer engagement and greater customer participation in energy efficiency initiatives.
In addition, the pilot suggests the potential for NTAs, as distributed grid resources, to provide substantial value beyond simple reduction of load on transmission system assets, GridSolar said, adding that NTA data is already providing deeper grid visibility, which enhances the ability to deploy smarter NTA – and transmission – assets over time, when, where and as needed.
GridSolar said that in terms of how to develop and operate NTAs most effectively, the pilot has shown the distance between the theoretical concept that distributed NTA resources might be able to offset and meet reliability requirements, and the end state necessary to consistently meet grid reliability requirements.
To work, the process requires a precise statement of requirements, development of specific NTA projects that meet size, location, and performance criteria, placed under contract, integrated with the grid, tested, monitored, operated, and in some cases re-commissioned, reconfigured, or replaced, GridSolar said.
“NTA solutions require careful up-front coordination, a dedicated communications and dispatch infrastructure, and ongoing administrative support and oversight – which, arguably, will be most successfully done by an entity with a commercial interest in the continuing (and expanding) success of NTA solutions and the obligation to see it through,” GridSolar said.
Discussing the results by NTA resource category, GridSolar noted, for instance, that the costs of solar PV systems have continued to fall since GridSolar issued RFP I and RFP II.
“With the extension of the federal tax credits and regional RPS requirements, we expect solar PV to be a very attractive NTA resource over the next five years,” GridSolar said. “It may get even better with the pending implementation of federally mandated Clean Power Plans in the New England states.”
Of storage, GridSolar noted that the pilot used two forms of storage technologies – ice banking in the form of the Ice Bear units deployed at a number of commercial establishments in the pilot area, and a 500-kW battery storage unit that is directly connected to a distribution circuit. Both types of resources represent proven technologies and have demonstrated an ability to provide grid reliability services in multiple tests under the Boothbay Pilot, GridSolar said.
The battery storage unit was the most expensive of the NTA resources procured, and the last one to come online, GridSolar said. While costly, it is also the most versatile and within its overall discharge and recharge parameters, provides the most flexibility and the most rapid response time.
“GridSolar expects that battery storage will generally remain among the most expensive NTA resources unless major technological breakthroughs can be achieved,” the company added.
Nevertheless, GridSolar said that there are a few factors it believes might improve the cost-effectiveness of this NTA resource, including that the per unit cost of battery storage has fallen significantly over the past few years and is expected to continue to fall.
Among other things, GridSolar said that aside from a few of the Ice Bear units, it was not successful in attracting demand response resources to participate in the pilot. In part, that reflected the uncertainty about how the pilot was going to operate and specifically its replicability, and therefore the economic return to potential participants that might otherwise bid in such resources.
CMP is a subsidiary of Iberdrola USA, which is a subsidiary of Iberdrola S.A. Emera Maine is wholly owned by