Distributed Generation

Utilities

Deregulation and competition in the electric power industry, along with technological advances in a variety of smaller-scale generation systems, have paved the way for substantial deployment of distributed generation (DG) in the United States and other markets.  From a technical perspective, DG runs against the grain of the design principles upon which almost all the infrastructure for electric distribution systems has been based.  On the economic side, newly created free markets for electricity supply have resulted in substantial price volatility, which in and of itself could be a boon for DG, but may also signal financial risk. Electrotek Concepts offers a full range of services for implementation and optimization of distributed generation.  Electrotek’s services include:

Feasibility assessments – Electrotek maintains the knowledge, tools, and experience to help utilities and power users evaluate DG as an electric supply option. 

Interconnection analysis – Approval to operate in parallel with the electric utility supply is generally contingent upon completion of technical studies that consider safety, protection, and performance issues as well as distribution system impacts.  Operating a distributed generator in isolation avoids issues related to utility interconnection, but brings its own set of operational questions.  From the utility perspective, concern for distribution system impacts increases as the amount of DG on a particular feeder rises.  Electrotek has extensive experience with interconnection of DG, and have worked with many utilities, research organizations, and standards-making bodies (IEEE, IEC) on interconnection issues. 

Power quality (PQ) assessments – With the potential for DG standards to become more stringent as the number of DG technologies on the grid increases, the demand to know more about the PQ emissions and immunity of DG systems will increase. Soon, the IEEE 1547 may require every DG system to be monitored for PQ. DG has the potential to increase the reliability and quality of an end-user’s electric supply. If not properly designed and implemented, however, DG can have the opposite effect.  Electrotek has extensive experience in assessing the impact of DG on power quality, and can recommend solutions to reduce or eliminate related problems.

Technology evaluation – Although DG technologies have reached a stable level of maturity, new technologies are on the horizon as DG becomes a more popular option for utilities and power users. New technologies will present a new line of choices and new concerns regarding which technologies should be considered for future DG installations. Electrotek has the in-depth experience to review the available options and make recommendations to ensure today’s DG systems perform to today’s standards.

Distribution system planning – For utilities, this is remains a critical issue as utilities prepare to expand their current fleet of DG installation as they continue to address diminishing generation and distribution capacity. As previously described, Electrotek has extensive distribution system planning and power system analysis capabilities that enhance the planning process beyond levels that competitors can provide.

Along with these capabilities, Electrotek offers performance combined with power quality monitoring of DG applications, as well as training on integrating DG into both customer and utility power systems.  Leveraging our strong R&D background, Electrotek is partnered with Dranetz Technologies, Inc. to develop information collection systems and control technologies that will facilitate aggregation of DG assets to supply power to utility grids during peak periods.

Electrotek uses leading-edge tools to perform power system modeling, simulation, and analysis for distributed generation applications. These tools include simulation software such as SuperHarm®, EMTP-RV®, and PSCAD® as well as Electrotek’s DistcoSuite® software distribution system simulation package. DistcoSuite® can assess current conditions on a power distribution network and perform “what if” analyses for integration of distributed generation. SuperHarm®, EMTP-RV®, and PSCAD® assist in analysis of DG on power quality and power system performance.

To meet customer demand for training in this area, Electrotek has a series of DG training workshops that address issues relating to the interconnection of DG to the utility distribution system. This seminar addresses the motivations for connecting DG as well as the operational issues that need to be considered. Evaluation methods for assessing DG for system planning purposes are also covered. The workshop can be presented at Electrotek’s Power Quality Training Center in Knoxville, Tennessee or on-site at a utility’s facility or be scheduled for open enrollment.

Architecture & Engineering Firms

A&E firms are becoming increasingly involved in designing, upgrading and maintaining DG installations for utilities—regulated and deregulated. As DG continues to offset more of the need for traditional electricity generation system, A&E firms will experience an increase in the demand for power quality engineering services (PQSE), focusing on the effects of PQ disturbances on the grid generated by DG operations and vice versa.

PQ problems related to harmonics, transients, voltage sags, etc. generated by the grid that cause DG installations to trip offline cost DG owners and investors thousands of dollars in lost revenue and an interruption in DG power injection into the grid. DG installations are also becoming larger. For example, Southern Company’s Georgia Power System is the US national leader for DG vis solar photovoltaic (PV) farms. Increased use of DG will generate more PQ problems along with some new problems. One of the new PQ problems is the increase in the conducted emissions in the 1 kHz to 150 kHz range found primarily in solar PV installations.

Electrotek’s in-depth experience in PQ combined with their EMC engineering knowledge places them at the forefront of modeling and simulations regarding DG installations. Modeling and simulations of DG installations has also focused on the high-frequency characteristics of radiated and conducted emissions generated by the PV inverters (central and distributed). The design and application of high-performance electromagnetic interference (EMI) filters on the AC and DC networks of DG systems (e.g., solar PV) can be modeled and simulated before filters are made and installed.

Electrotek uses leading-edge tools to perform power system modeling, simulation, and analysis for distributed generation applications. These tools include simulation software such as SuperHarm®, EMTP-RV®, and PSCAD® as well as Electrotek’s DistcoSuite® software distribution system simulation package. DistcoSuite® can assess current conditions on a power distribution network and perform “what if” analyses for integration of distributed generation. SuperHarm®, EMTP-RV®, and PSCAD® assist in analysis of DG on power quality and power system performance.

Equipment Manufacturers

As the cost of electricity continues to increase, more equipment manufacturers (i.e., industrial utility customers) will continue to invest and use DG technologies to power their plants. Solar PV will likely be the primary technology of choice. Each new DG user will be required to have modeling and simulation studies performed to ensure the IEEE 1547 interconnection requirements are followed.

Interfacing the DG power system to the plant electrical system must be based on a thorough and in-depth PQ study to ensure the risks of developing PQ problems are properly managed and controlled. Such PQ problems include harmonics control, conducted emissions control, the effects of plant-generated transient voltages on the DG system and voltage sag immunity of the DG system among other issues.

Electrotek uses leading-edge tools to perform power system modeling, simulation, and analysis for distributed generation applications. These tools include simulation software such as SuperHarm®, EMTP-RV®, and PSCAD® as well as Electrotek’s DistcoSuite® software distribution system simulation package. DistcoSuite® can assess current conditions on a power distribution network and perform “what if” analyses for integration of distributed generation. SuperHarm®, EMTP-RV®, and PSCAD® assist in analysis of DG on power quality and power system performance.

End User

The use of DG technologies at commercial facilities to offset the need to purchase electricity is also increasing. Such facilities include airports, warehouses, retail establishments, small businesses and large business among others. End users who rely on DG systems to provide their power must clearly understand the risk in doing so. Although most end users still remain connected to the grid, disconnection of the DG system from their facility power system can present economic problems to them if the reason for disconnection is not resolved on short order.

Moreover, their DG system must be resilient to grid-generated PQ disturbances incident on that DG system. Their DG system must also be immune to disturbances caused by operating the commercial facility. Managing the risk of developing a PQ or EMI problem must be carefully thought through, so the risks are controlled.

Electrotek uses leading-edge tools to perform power system modeling, simulation, and analysis for distributed generation applications. These tools include simulation software such as SuperHarm®, EMTP-RV®, and PSCAD® as well as Electrotek’s DistcoSuite® software distribution system simulation package. DistcoSuite® can assess current conditions on a power distribution network and perform “what if” analyses for integration of distributed generation. SuperHarm®, EMTP-RV®, and PSCAD® assist in analysis of DG on power quality and power system performance.