A second structural impediment to fully realizing DER benefits is the current grid planning approach, which biases grid design toward traditional infrastructure rather than distributed alternatives, even if distributed solutions better meet grid needs. Outdated planning approaches rely on static assumptions about DER capabilities and focus primarily on mitigating potential DER integration challenges, rather than proactively harnessing these flexible assets.
Section II demonstrated how California could realize an additional $1.4 billion per year by 2020 in net benefits from the deployment of new DERs during the 2016-2020 timeframe. This state-wide methodology was then applied to the planned distribution capacity projects for California’s most recent GRC request, showing how the deployment of DERs in lieu of planned distribution capacity expansion projects in PG&E’s next rate case could save customers over $100 million.
Designing the electric grid for the 21st century is one of today’s most important and exciting societal challenges. Regulators, legislators, utilities, and private industry are evaluating ways to both modernize the aging grid and decarbonize our electricity supply, while also enabling customer choice, increasing resiliency and reliability, and improving public safety, all at an affordable cost.
Smart grids are a highly sophisticated way of achieving efficiency and reliability in power distribution. At present, the power distribution network in most regions has a significant supply-demand gap, due to the steadily rising demand for electricity. This gap is most prominent in Asia Pacific, where the combination of a rapidly rising population, rising standard of living, and inefficiency in power generation and distribution has led to the demand for supplementary power and the means to eliminate the wastage of power during distribution.
Motivated by the challenge faced in designing a grid appropriate to the 21st century, this report first focuses on determining the quantifiable net economic benefits that DERs can offer to society. The approach taken builds on existing avoided cost methodologies – which have already been applied to DERs by industry leaders – while introducing updated methods to hardto-quantify DER benefit categories that are excluded from traditional analyses. While the final net benefit calculation derived in this report is specific to California, the overall methodological advancements developed here are applicable across the U.S. Moreover, the ultimate conclusion from this analysis – that DERs offer a better alternative to many traditional infrastructure solutions in advancing the 21st century grid – should also hold true across the U.S., although the exact net benefits of DERs will vary across regions.
The share of renewables in overall power generation is rapidly increasing, both in developed and developing countries. Furthermore, many countries have ambitious targets to transform their power sector towards renewables. To achieve these objectives, the structure and operation of existing power grid infrastructures will need to be revisited as the share of renewable power generation increases.
Renewable energy technologies can be divided into two categories: dispatchable (i.e. biomass, concentrated solar power with storage, geothermal power and hydro) and non-dispatchable, also known as Variable Renewable Energy or VRE (i.e. ocean power, solar photovoltaics and wind). VRE has four characteristics that require specific measures to integrate these technologies into current power systems: 1) variability due to the temporal availability of resources; 2) uncertainty due to unexpected changes in resource availability; 3) location-specific properties due to the geographical availability of resources; and 4) low marginal costs since the resources are freely available.
A transition towards high shares of VRE requires a re-thinking of the design, operation and planning of future power systems from a technical and economic point of view. In such a system, supply and demand will be matched in a much more concerted and flexible way. From a technical perspective, VRE generation can be ideally combined with smart grid technologies, energy storage and more flexible generation technologies. From an economic perspective, the regulatory framework will need to be adjusted to account for the cost structure of VRE integration, to allow for new services and revenue channels, and to support new business models.
There are several technological options that can help to integrate VRE into the power system grid: system-friendly VREs, flexible generation, grid extension, smart grid technologies, and storage technologies. New advances in wind and solar PV technologies allow them to be used over a wider range of conditions and provide ancillary services like frequency and voltage control. Flexible generation requires changes in the energy mix to optimise production from both dispatchable and non-dispatchable resources. Smart grid technologies can act as an enabler for VRE integration, given their ability to reduce the variability in the system by allowing the integration of renewables into diverse electricity resources, including load control (e.g. Demand Side Management (DSM), Advanced Metering Infrastructure (AMI), and enhancing the grid operation and therefore helping to efficiently manage the system’s variability by implementing advanced technologies (e.g. smart inverters, Phasor Measurement Unit (PMU) and Fault Ride Through (FRT) capabilities).
Energy storage technologies can alleviate short-term variability (up to 2 Renewable Energy Integration in Power Grids | Technology Brief several hours), or longer-term variability through pumped-storage hydroelectricity, thermal energy storage or the conversion of electricity into hydrogen or gas.
Two immediate applications for deploying innovative technologies and operation modes for VRE integration are mini-grids and island systems. The high costs for power generation in these markets make VREs and grid integration technologies economically attractive since they can simultaneously improve the reliability, efficiency and performance of these power systems. This is, for example, the case of the Smart Grid demonstration project in Jeju Island, South Korea.
Furthermore, the right assessment and understanding of VRE integration costs are relevant for policy making and system planning. Any economic analysis of the transition towards renewables-based power systems should, therefore, consider all different cost components for VRE grid integration, such as grid costs (e.g. expansion and upgrading), capacity costs and balancing costs. Integration costs are due not only to the specific characteristics of VRE technologies but also to the power system and its adaptability to greater variability. Therefore, these costs should be carefully interpreted and not entirely attributed to VRE, especially when the system is not flexible enough to deal with variability (i.e. in the short-term).
Moreover, RE integration delivers broader benefits beyond purely economic ones, such as social and environmental benefits. Even though not straightforward, these externalities should be considered and quantified in order to integrate them into the decision-making process and maximise socio-economic benefits.
Due to the rapid technological progress and multiple grid integration options available, policy makers should build a framework for RE grid integration based on the current characteristic of the system, developing technological opportunities and long-term impacts and targets. In particular, policy makers should adopt a long-term vision for their transition towards renewables and set regulatory frameworks and market designs to foster both RE development and management of greater system variability. Such regulatory frameworks could include new markets for ancillary services and price signals for RE power generators that incentivise the reduction of integration costs.
Source: IEA-ETSAP and IRENA