Smart Grid Integration A Daunting Task As Green Energy Comes Online

As alternative green energy sources come online, power plants and energy distribution substations find their networks challenged by smart grid demands that call for rapid changes between traditional and alternative energy sources. System and network integration on a smart grid that manages hybrid energy sources is on technology road maps for virtually every utility company now, but a majority are still not diversified with alternative energy.  Consequently, the prospect of integrating traditional and alternative energy systems with networks looms large.

For instance, when California Independent System Operator (ISO) installed a new renewable energy market system with all of the features and capacity it thought it would need for its renewable energy sources, it was a $199 million project with extensive revisions to hardware and software infrastructure, entailing the training of personnel over a one year time period. The system had to be up to the challenge of running a very diverse energy management system with a variety of energy sources. "Right now, we use nuclear, gas, wind, geothermal, bio-mass and hydro energy sources," said Jim McIntosh, Director of Grid Operations for California ISO. "We wanted a system with all of the features and capacity that we felt we would need in a diverse energy environment."

California ISO isn't the only one working on revisions to system and network infrastructures for energy management that includes green energy. Utilities in Denmark, Germany, Spain and China are well along in incorporating and distributing wind power. In Asia-Pacific, the U.S. Navy is looking for reliable alternative energy sources to improve distribution options in often fluctuating conditions. "In Hawaii, when the power goes off, the entire island can go black," said retired Navy Captain Chris Honkomp. "One of the issues that we face there is that the power generation is almost 100 percent petroleum-based." To improve the situation, the Navy is looking to build power generation plants for bio-fuels and solar power. "We have a small power grid in Hawaii," said Honkamp, "But a major concern for us has been how we will integrate and manage all of these diverse energy sources."

"In particular, we see wind energy taking off," said Alison Silverstein, an independent energy consultant based in Austin, Texas, "But when it comes to the system and network integration needed to link all of these diverse energy sources together, it's more talk than action."   Silverstein feels that the system and network integration required for the distribution of hybrid energy sources is one of the major drivers behind the smart grid. "Unfortunately, right now, enthusiasm for this kind of systems integration exceeds reality," said Silverstein. "We can do many things, but we still need to understand the detailed analytics, communications and controls that are used in utilities and other industries, and that must go into the integration."

The North American Electric Reliability Corporation's (NERC) Long-Term Reliability Assessment conducted in 2008 corroborates Silverstein's statements. It states that integrating diverse energy sources, many of them variable (e.g., wind, solar), will demand revisions to systems, networks and operations and a level of IT integration that utilities have not had to consider before."When you use energy sources like wind that are variable, one of the challenges you face is forecasting," said Jim McIntosh of CAL ISO. "How do you forecast a day ahead? Ramping a system for wind is also a challenge, because the strength of the wind tends to be inversely proportional to the load curve of energy demand. During the summer, for example, the wind is strongest at night, but wind velocity is down during the day, when we have the peak load."   McInTosh also says that the energy ramps with wind, unlike those of traditional fuels, tend to be much steeper. This is because the variability of wind does not give a utility the opportunity to gradually ramp as it can with a steady and predictable energy source like petroleum.

Despite ramping and other inherent challenges in variable energy source management, Navy Captain Ret. Chris Honkomp said that diverse and intermittent power is in the plan for the Navy's Asia Pacific operations. "We want to conquer intermittent power so that if the sun isn't shining, maybe the wind is blowing," said Honkamp. "We are even looking into energy from waves. We want to reduce our dependence on petroleum products, and we know that we have to have the system and network integration to utilize these alternative energy sources. It is too early for us to know how we will solve system integration problems, and we are anticipating growing pains, but this will not deter us."

The federal government is also pushing utilities to pursue alternative energy sources.  Over the next decade, NERC reports that over 145,000 MW (megawatts) of variable energy resources will be added to the North American bulk power system. NERC says that if only half of this capacity comes online, it will represent a 350 percent increase in variable energy use over 2008 and will constitute one of the largest resource integration efforts in the history of the electric industry. This transition will demand many changes in infrastructure, policies, administration and operations. On the systems and networking side, it will be critical to manage ramping, energy source coordination, system metrics and controls and forecasting. All depend on effective system and network integration.

"We have been told to focus on renewable energy, and that return on investment (ROI) isn't necessarily the most important thing," said the Navy's Chris Honkamp. "We have an ocean thermal energy conversion plant on Diego Garcia, a small island in the Pacific, and are in the process of determining whether this energy source can be viable on Guam or in Hawaii. We are concurrently working at establishing diversified energy in Hawaii. The big question is, how do you integrate all of this?"