Future Energy

Integrating Renewables into the Grid - Its All About Flexibility

Source: techvert.com

Back in mid-January, Stanford's TomKat Centre for Sustainable Energy hosted the Grid Integration of Renewables Workshop, bringing together a group to examine the issues relating to grid expansion and the integration of renewables into that grid.  I came across a report on the workshop at the CleanTech blog that interested me but was unable to get much detail about the discussions. 

Sometime in the past few weeks, the TomKat Centre posted most of the presentations given at the workshop.  Collectively they provide an interesting picture of the issues at least these experts foresee as the proportion of intermittent renewables such as wind and solar that are connected to the grid becomes significant.

Keynote Speakers included U.S. Senator Jeff Bingaman (New Mexico) and Commissioner Jeffrey Byron of the California Energy Commission (CleanTech blog's report focuses on what the keynote speakers had to say in lots of detail so I won't try to add anything here).

Speakers included:

• Gregor Czisch, Transnational Renewables, Germany - The Supergrid: 100% Renewable Electricity Supply for Europe and Its Neighborhood » (ppt)
• Mark Jacobson, Stanford - Grid Integration Challenges for 100% Conversion to Wind and Solar Power » (pdf)
• Hans Henrik Lindboe, Ea Energy Analyses, Denmark - Enabling Renewable Energy Integration in Denmark » (pdf)
• V. John White, Center for Energy Efficiency and Renewable Technologies - Pulling the Pieces Together: Thinking Regionally and Cooperatively » (pdf)
• Antonio Alvarez, PG & E - Efforts and Challenges to Manage California's Expected Intermittent Renewable Additions » (pdf)
• Debbie Lew, National Renewable Energy Laboratory - Finding Flexibility in the Existing System » (pdf)
• Nick Jenkins, Cardiff University, UK - Optimizing AC and DC Transmission Networks for High Penetration of Renewables » (pdf)
• Michael Wara, Stanford - Key Regulatory Challenges for Deep Penetration of Renewables (no links provided)
• Willett Kempton, University of Delaware - Low Cost Grid Integration via Met-Smart Interconnection and Storage Inherent in End-Use Devices » (pdf)

The clearest point of agreement running through the speakers' presentations was that increased reliance on non-hydro renewables would lead to greater uncertainty of supply, which would in turn demand greater flexibility within the management of the grid if supply and demand were to be successfully balanced.  Suggested mechanisms for achieving the necessary flexibility generally fell into one of three categories, including:

Increase the Size of the Catchment

Speakers identified a range of approaches that relate to increasing the size of the area from which power can be drawn from to lessen the chance that power is available due to weather issues.  Suggested mechanisms included imports, Balancing Area cooperation and development of "asynchronous" resources (i.e. resources that are expected to be couter-cyclical in the availability).  The underlying assumption of efforts to increase the size of the catchment being that its always windy somewhere.  Needless to say, just about any approaches relying on increased catchment size demand big investments in transmission infrastructure - perhaps one of the most significant challenges facing future grid development.

Better Manage  Supply

While some of the suggestions appear to focus primarily on the need for standby conventional power sources, more creative approaches included development of asynchronous sources, as noted above, and the need for grid storage.

Better Manage Demand

Clearly an approach with a lot of future potential as Smart Grid technologies are developed, speakers focused on automatic demand response technologies, "dynamic pricing" (i.e. higher pricing during times of the day that electricity is in greater demand or less available) and curtailment or the ability to automatically cut off some customers or applications as demand increases/supply decreases.

When you say them fast, these all sound pretty simple.  But they represent significant shifts in approach, huge infrastructure investments and potentially years of regulatory and public process to put in place. 

Still an interesting collection of views on what seems the most likely future direction for electricity.

A Smart Grid for a Green Future

Source: Treehugger.com

The Economist has provided a good description of the Smart Grid and why it is so important to a sustainable energy future in its current issue (see Building the Smart Grid, June 4th).

AROUND the world billions of dollars are being invested in clean-energy technologies of one sort or another, from solar arrays and wind turbines to electric cars. But there is a problem lurking in the power grid that links them together. Green sources of power tend to be distributed and intermittent, which makes them difficult to integrate into the existing grid. And when it comes to electric cars, a study by America’s Pacific Northwest National Laboratory (PNNL) found that there is already enough generating capacity to replace as much as 73% of America’s conventional fleet with electric vehicles—but only if the charging of those vehicles is carefully managed. In order to accommodate the flow of energy between new sources of supply and new forms of demand, the world’s electrical grids are going to have to become a lot smarter.

Even though the demands being placed on national electricity grids are changing rapidly, the grids themselves have changed very little since they were first developed more than a century ago. The first grids were built as one-way streets, consisting of power stations at one end supplying power when needed to customers at the other end. That approach worked well for many years, and helped drive the growth of industrial nations by making electricity ubiquitous, but it is now showing its age.

The U.S. administration certainly appears to listening to the need to move towards a smarter grid.  In the Christian Science Monitor's bright green blog, Mark Clayton profiles Jon Wellinghoff, Chair of the Federal Energy Regulatory Commission (see Jon Wellinghoff, Obama's energy futurist, June 8th).

In Wellinghoff’s vision of the future, where the cost of carbon dioxide emissions is added to the price of coal-fired power plants and natural-gas turbines, it may be less expensive for consumers to set their appliances to avoid buying power at peak times. Or they may choose to buy power from a collection of microturbines, fuel cell, wind, solar, biomass, and ocean power systems.

“We’re going to see more distributed generation – and we’re already starting to see that happen,” Wellinghoff says. “Not only renewable generation like photovoltaic [panels] that people put on their homes and businesses, but also fossil-fuel systems like combined heat and power,” called cogeneration units.

To coordinate and harmonize this fluctuating phalanx of power sources, customers will need to know and be able to respond to the price of power, Wellinghoff says. They will also need a new generation of appliances that switch off automatically to balance power supply and demand peaks.

And so do the U.S. utilities.  In Green News, CNET's environment blog, Martin LaMonica covers announcements by Duke Energy and ComEd of their chosen Smart Grid suppliers (see Cisco, Silver Spring Networks land smart-grid deals, June 9th).

Duke said that it has chosen Cisco to supply an array of equipment for a planned smart grid program estimated at $1 billion over the next few years. Cisco, which unveiled its smart-grid initiative last month, is expected to supply in-home energy monitors as well as networking hardware for Duke's substations, the utility said.

North Carolina-based Duke aims to provide a digital upgrade to its 11 million customers in the five states it operates.

"Replacing our analog electric grid with advanced digital technology to create a 21st century electricity delivery system largely involves data, networks, and communications--all of it Cisco's expertise," Todd Arnold, senior vice president for smart grid and customer systems at Duke Energy, said in a statement..........

Chicago-based ComEd on Tuesday announced its recommended providers, including General Electric for smart meters and Silver Spring Networks, which provides wireless communications and software.

If approved, the smart grid program would bring real-time information on electricity usage and rates to consumers by installing 141,000 two-way meters in 11 Chicago suburbs.........

Seven-year-old Silver Spring Networks has emerged as one of the most successful providers, having secured deals with a handful of utilities, including Florida Power & Light.

Cisco, meanwhile, is making a concerted push around energy efficiency and grid modernization, developing a full line of communications products for utilities, consumers, and building managers.

So the question I have now is where are the Canadian utilities and technology suppliers?

Figuring Out Smart Grid

Google's PowerMeter

Source: Google.org

I've been spending some time lately reading about the "smart grid" and trying to understand what it means.  The short answer seems to be that the smart grid is whatever you want it to be, with companies ranging from General Electric to Google each staking their claim to some part of this marriage of electricity transmission and IT.  I intend to write a couple of posts about it and the companies involved.  In the meantime, you might be interested in Google's recent announcement of home energy software for the delivery end of the grid.

"Google PowerMeter receives information from utility smart meters and energy management devices and provides customers with access to their home electricity consumption right on their personal iGoogle homepage. We are currently testing Google PowerMeter with a number of utilities and plan to expand our rollout later this year."

For more information, the NYTimes Green Inc. blog tells the story better than I can.