The merits of integrating renewables with smarter grid carimet

Editor's Notes

• #10: Ramping demands: Increased solar puts stress on the system when the sun rises and sets. Conventional generation must ramp down and up to compensate. Over-generation can be a problem when solar output peaks in the early afternoon if demand levels are modest and  inflexible base load generation bumps up against minimum output constraints. Declining marginal value: As the level of renewables penetration (solar in particular) increases, renewable energy output becomes less coincident with peak net load. This drives down the marginal value of the electricity generated, in part by reducing the capacity value of solar on the build margin and in part by driving up the marginal cost of managing variable energy output.
• #12: Power systems must be actively managed to maintain a steady balance between supply and demand. This is already a complex task as demand varies continually. But what happens when supply becomes more variable and less certain, as with some renewable sources of electricity like wind and solar PV that fluctuate with the weather? To what extent can the resources that help power systems cope with the challenge of variability in demand also be applied to variability of supply? How large are these resources? And what share of electricity supply from variable renewables can they make possible? Power systems differ tremendously in design, operation and consumption patterns, in the natural resources that underpin them, the markets they contain, and the transmission grids that bind them together. Furthermore, and as this analysis shows, there is likely to be a wide gap between what is technically possible and what is possible at present. In other words, some systems are better able than others to manage large VRE shares of electricity production, and direct comparison among them of VRE deployment potential from the integration perspective is inappropriate. Integrated Resource Planning using the Flexibility Assessment (FAST) method developed by the IEA’s Grid Integration of Variable Renewables (GIVAR) project. ● Step 1 assesses the maximum technical ability of the four flexible resources to ramp up and down over the balancing time frame.5 This is the Technical Flexible Resource. ● Step 2 captures the extent to which certain attributes of the power area in question will constrain the availability of the technical resource, to yield the Available Flexible Resource. ● Step 3 is to calculate the maximum Flexibility Requirement of the system, which is a combination of fluctuations in demand and VRE output (the net load)6 , and contingencies. ● Step 4 brings together the requirement for flexibility and the available flexible resource to establish the Present VRE Penetration Potential (PVP) of the system in question.
• #13: Grid hardware such as smart grid technologies can play several important roles to balance the fluctuation in “net load.”† Specifically, smart grid technologies are integral components of the categories of “Demand side management and response” and “Energy storage facilities.”
• #14: In light of this definition, smarter grids play a role in several domains within the IEA categorization of flexible resources. We now focus on a deeper discussion of how smart grid applications and technologies could enable power system flexibility in support of VRR integration Jamaica with VRR shares set to exceed 10% in 2016 has to seriously look toward smart grid solutions to maintain safety, security, reliability and economics The challenges presented by VRR integration will vary significantly by region, grid topology, and type of VRR resources on the grid. Consequently, the appropriate portfolio of integration tools will be specific to each grid system. In order to better contextualize smart grid tools within the full toolbox available to system operators, the next section provides a broad overview of key VRR integration challenges and outlines four categories of available tools: smart grid, markets, system operation, and other. ‡
• #16: The integration challenges are taken in the context of other solutions that are available, some which are soft and already available..
• #19: In some instances, the ramping requirements driven by variable generation and variable demand may offset each other, while in other cases they may combine to require even more ramping capacity. Additionally, the interplay between different VRR sources may be important, for example in regions where wind speeds tend to increase in the evening during the same time that solar begins to decrease. In Jamaica there is the potential for interplay between wind and solar peaking at the same time with a great degree of overlap.
• #27: US researchers report roughly 38,000 MW of existing demand response capacity in the United States.[17] Activating demand-side flexibility is not simply a technical question however -- it requires a mix of complementary policy, regulatory, and market measures, which should be coordinated with the desired type of demand-side participation in mind.
• #28: Smart grid technologies and systems can cost-effectively enable demand-side flexibility in several ways. On the one hand, traditional (or managed) DR leverages networks and machine-to-machine communication protocols to manage demand based on real time price and/or load conditions. On the other hand, price-responsive (or active) DR leverages consumer and market participant responses to price in order to shift load. Traditional demand response is centrally controlled by the vertically-integrated utility and has historically focused on reliability operations (e.g. managing load peaks). Price-based demand response, managed through a market with increased customer participation, encompasses a wider range of potential products, potentially playing significant roles in capacity, energy, and ancillary services markets, as well as in congestion management. Automated demand response (“AutoDR” or “ADR”), which facilitates direct communication between building automation systems and electricity markets, is now technologically mature, but focuses mainly on demand response for peak demand reduction. Demonstration of technologies (including AutoDR) for load-following generation are now being conducted in several countries. Active, smart grid–enabled DR promotes greater price-responsiveness of customers and market participants through real-time pricing delivered via machine-to-machine communication, in-home devices, or mobile devices. The magnitude and flexibility of such resources is potentially quite large, but significant hurdles remain to its mainstream adoption in VRR-relevant power market operations – not least of which are uncertainties around likely rates of consumer participation. The critical policy issues facing greater activation of price-responsive, next-generation DR include market design, pricing, rules of participation, and technical resource assessments Sedano, Levy & Goldman, 2010
• #31: The connection of small generators to the grid, such as rooftop PV, combined heat and power, diesel generators, gas turbines, fuel cells, and run-of-the-river hydro, is not a new phenomenon. For safety reasons, the traditional approach in integrating distributed generation is to set the protection and the voltage regulation of the generator to avoid cases of islanding during an outage. Islanding occurs when a generator is running, feeding the customers, while the main source is removed, either intentionally or through an unintentional service outage.
• #33: The adoption of advanced information and communication technologies into grid control rooms is enabling dramatic advances in power system management. Key enabling systems include high-resolution visualization of grid status and health, automated demand management, algorithms that identify critical (i.e. intermittency) events, integrated forecasting software that allows for more accurate market dispatch, and the ability to manage the connection (and disconnection) of large micro-grids
• #35: Considering the strong linkage between VRR and smart grid development and the magnitude of investments at stake, the following recommendations could help decision-makers in defining the appropriate course of action Recommendation 1: Ensure alignment between smart grid roadmaps and scenarios for future renewable energy supply. Smart grid technologies will be an increasingly important resource for integrating both large-scale and distributed renewable energy resources. The specific types of renewable resources to be developed, as well as the target mix of utility-scale and distributed resources, should inform the development of smart grid policies and capital investments. Scenarios that prioritize large-scale VRR will require a special focus on intelligent transmission solutions, while programs that prioritize DER, such as feed-in tariffs for small scale VRR development, will require a special focus on the way distribution networks are upgraded and operated Recommendation 2: Evaluate smart grid VRR integration solutions in the context of the full range of integration solutions. The pathway to successful VRR integration will be highly specific to each region, and will likely include various changes to system operation, power markets, and the cycling of dispatchable power plants. The integration of balancing areas, the development of efficient and open markets, and new or expanded transmission interconnections to dispatchable renewable plants (such as large hydro generators), may all be key candidates for addressing the VRR integration challenge. Smart grid solutions will typically complement these strategies, and in other cases they may represent cost-effective alternatives.