Distributed generation offers rich opportunities to address power grid challenges. But to really make these projects succeed, utilities should consider not just where generation resources are located, but also the bigger picture of the infrastructure supporting them.
Ultimately, a more robust and resilient energy distribution grid might eventually look like a patchwork of energy districts interconnected through the local utility infrastructure. This could significantly enhance grid efficiency and reliability, while also improving regional economic and development opportunities -- and utility business opportunities, as well.
For the majority of its existence, the electric grid has been powered with large, remote "centralized" generation. But today, a number of factors are now enabling significant modifications to this model -- in large part driven by the availability of distributed generation resources. Distributed generation both challenges existing grid designs and offers new opportunities to increase efficiency and resilience.
The generation and grid assets themselves are aging, consumer expectations in regard to reliability have grown significantly, and the rollout of renewable portfolio standards and greenhouse gas emission regulations have opened doors for integration of renewable energy generation at both the transmission and distribution levels. Though no single force is dominating the market, these challenges combined create greater opportunities to integrate distributed generation into an energy delivery grid that is becoming increasingly intelligent.
Distributed generation employs smaller-scale technologies and energy resources to produce electricity closer to end-users. Providing power generation nearer to the point of consumption can often decrease the cost, as well as reduce the interdependency and inefficiencies associated with transmitting power over long distances. Today's distributed generation landscape includes biomass, geothermal, hydro, solar, wind, natural gas and other options. While some technologies are still not cost-competitive with traditional generation modes, all are making advances and are appropriate under varying circumstances.
However, integrating distributed generation into grid solutions isn't solely about locating generation closer to the customer or offsetting local power costs. It should involve assessment and a conscious design of the infrastructure in the associated "energy district."
An energy district would be an area of a region or city whose energy needs can be managed as a cohesive and complementary subset of the overall grid, with the capability to be partially of fully self-sustained if supply from the local utility is lost. The intent is to develop a solution that allows the district to function continuously, or for a significant period of time, if the local utility supply is interrupted for any reason. They can be ultimately augmented with variable renewable resources and storage.
Essentially, distributed generation is being integrated to support the needs of the community, and the energy district becomes a small version of the larger smart grid -- a microgrid.
To maximize the effectiveness of distributed generation technologies, a strong and smart electrical infrastructure needs to be established. In general, it will include three major elements:
1. The ability to balance and manage the available generation and demand resources within the district in conjunction with the utility supply.
2. Modernization -- including automation, monitoring and control capabilities.
3. Visibility of energy usage to both district management and energy consumers, coupled with business and residential automation options.
Each of these segments has a range of products and companies to address particular challenges. However, the full value of the distributed generation and a smart grid will only be realized with the efficient integration of these elements. An effective, replicable decentralized design paradigm and methodology is essential.