Sandia National Laboratories is developing a microgrid architecture that holds the potential to revolutionize not only the microgrid industry, but all electricity generation. The secure scalable microgrid (SSM) will allow for 100% stochastic, or unpredictable, generation (e.g., solar PV and wind). Many companies and individuals have feared that renewable generation assets will compromise the stability of the electricity grid, and, under more traditional grid architectures, this makes sense intuitively. Since neither solar nor wind are load-following or dispatchable, they can wreak havoc in the absence of sufficient traditional generation or energy storage to compensate for the large swings in renewable production.
The SSM architecture includes a communication network that connects the loads to the generation assets, along with weather and load prediction, energy storage assessments, and a device to monitor the connection to the central utility. It uses Hamiltonian functions to balance and optimize generation and load given uncertainties in the data it collects. With an open architecture design, the SSM also promotes transparency of operation, configurability, extensibility to different systems, and its “plug-and-play” capability.
SSM is currently being tested at the SSM Test Bed in New Mexico, which includes programmable loads that mimic both fossil and renewable based generation, buses, and integrated control computers to effectively simulate the microgrid in Lanai, Hawaii. While there is no timeline yet for the commercialization of the technology, its eventual introduction into the market will allow for significantly greater penetration of renewables than are currently feasible.
Enabling the Green Grid
The major implication for SSM is that electricity generation can become completely renewable and independent of fossil fuels, a necessary step in the greening of the power grid. Environmental concerns aside, completely stochastic electricity production usually requires no fuel inputs. As the production costs associated with solar PV and wind turbines continue to decrease, and stochastic generation becomes economically competitive with traditional fossil fuel generation, the SSM should allow a transition to mostly, or completely, renewable electricity generation.
New Zealand and Austria, for example, have goals of 90% and 78% renewable generation, respectively, in the coming decades. While it’s relatively simple, if costly, to install sufficient qualifying generation, the task of ensuring grid stability is much more daunting. Germany has recently experienced grid issues due to its high penetration of solar, since power outputs can change very rapidly. The SSM grid architecture, if it can be scaled up for central grid use, would help to ensure that even significant fluctuations in power output from renewable sources can maintain consistent voltage and frequency across the grid.
In the near future, the SSM architecture will bolster the ability of utilities to meet renewable energy requirements by incorporating utility distribution microgrids (UDMs) into their portfolios and service areas. As described in the Navigant Research report Utility Distribution Microgrids, UDMs are forecast to increase 1,100 MW by 2018, and this trend will only be reinforced by the advent of the SSM.
Total UDM Capacity by Region, Average Scenario, World Markets: 2012-2018
(Source: Navigant Research)
Tags: Digital Utility Strategies, Distributed Renewables, Renewable Energy, Smart Grid Infrastructure
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