November-December 2010

Virtually Powerful

While renewables like wind and solar are often touted as the ultimate solution to all of our energy needs, the truth is that our current energy infrastructure is in no way ready to handle the variable energy output generated by many of these renewable energy sources. And while there’s always the possibility that the promised smart grid will be designed and implemented with an eye towards incorporating renewable energy, this type of radical infrastructure modification does not lend itself to immediate implementation.

But what if there was an easier way? What if we could combine the best of our current power grid with clusters of distributed energy installations to deliver reliable—even peak load—electricity? I’m talking about the Virtual Power Plant (VPP). With a VPP, dispersed power sources are grouped together and managed via a centrally controlled, Web-based system, ultimately creating the virtual equivalent of a centralized power station. (For more, go to www.distributedenergy.com/DE/Articles/Defining_the_VPP_12515.aspx.)

VPPs have an advantage over microgrids because, while a microgrid involves a localized grouping of energy sources that are connected to the main grid but can operate autonomously, VPPs add an extra layer of control via specially designed software that allows interplay between generation points. What that means on a practical level is that with a VPP, different power generation sources—wind, solar, and biomass, for example—can operate independently or be combined to create a more reliable whole. 

Reliability has always been renewable energy’s Achilles’ heel: How do you keep the lights on when the sun goes down and the wind stops blowing? By employing energy management software and smart meters, VPPs can overcome the reliability challenge.  VPP software allows for peak load control as well as a source-flexibility (i.e., switching from one power source to another based on supply, demand, and reliability). Demand management and grid function reliability are also insured with VPPs via real-time demand response and load shifting.

In Europe, several VPP pilot programs are already underway, but in the US, VPPs are still in their embryonic stage. The every-growing popularity of wind farms and onsite solar could change all that. After all, those of us involved in the implementation of distributed energy systems and/or active in the promotion of energy efficiency programs, have experienced first hand how demand for renewable energy options has increased exponentially over the last few years. But we also know that implementation is tricky, especially when electric utilities are still struggling with the logistics involved in incorporating distributed energy into a centralized power grid.

Which is why VPPs make sense. Unlike the smart grid, incorporating VPPs into our current energy infrastructure would be a relatively painless process. We all know that placing our faith in the centralized utility system—even an intelligent one—will not work without incorporating customer-owned, onsite power generation. And while the smart grid folks contend with energy storage issues and security concerns, VPPs can quietly slip into our current system: supplying us with all the benefits of a smart grid without out a major restructuring of our present energy delivery systems. 

For those of us who are aware that neither our current energy infrastructure nor the future smart grid can fully capitalize on the benefits of onsite renewable energy, the possibilities of a VPP are tantalizing. Imagine an easily integrated system that can play off the strengths of each individual power source—allowing one to compensate for and offset the other—to create a steady stream of renewable power essentially indistinguishable from conventional electric utilities. With VPPs, that future can happen now.