The micro(grid) solution to the macro challenge of climate change
"We have met the enemy and he is us."
So said the long-running American comic strip character Pogo in a 1970 Earth Day poster about pollution. The Intergovernmental Panel on Climate Change, the world's most respected scientific authority on the climate change topic, recently said much the same thing.
The group released its highly anticipated Fifth Assessment Report (AR5). This latest report largely confirmed or reiterated previous observations and conclusions, hammering home two major takeaways in particular: Climate change is happening and we are causing it. The biggest culprit is greenhouse gas (GHG) emissions, chiefly because of fossil fuel combustion, although deforestation also has been an important contributor.
Ironically, while the fossil-fuel-burning energy sector is the largest contributor to global GHG emissions, it is also one of the industries most vulnerable to climate change. The Department of Energy released a sobering report in July describing the vulnerabilities of the U.S. energy sector to climate change and extreme weather. Globally, increasing temperatures are accompanied by increasing droughts, greater wildfires and more severe storms, all of which wreak havoc on our energy system.
This dichotomy -- of energy system as both villain and victim -- leaves policy makers, regional planners and many other stakeholders across the world faced with a gnarly dilemma when it comes to the future of climate change. How do you make energy infrastructure more resilient to the threats of climate change, while also reducing the GHG emissions generated from energy generation, transmission and distribution?
The climate change dilemma: Mitigate or adapt?
In the wake of Superstorm Sandy, officials in heavily impacted coastal cities such as New York City are faced with a difficult decision: Should they work to combat climate change and prevent sea level rise and storms from hitting in the first place, an admittedly long-term and global issue? Or should they invest in building high sea walls and other protective measures to buffer the city from the next assault, a more immediate action? With limited municipal budgets, could they do both?
The first action refers to climate change mitigation; the second to climate change adaptation. In a world of limited resources, these choices may appear mutually exclusive, but the reality is they don't have to be. Investing in microgrids -- smaller subsets of the grid that can operate either as part of the macro-grid or autonomously as "islands" -- that integrate distributed, renewable resources can provide us an energy infrastructure that is both more reliable and more sustainable all at once.
The microgrid solution
Not that long ago, I wrote a piece describing how a microgrid could help you survive a zombie apocalypse; the reality is microgrids can help us both prepare for and prevent the much more realistic threat of climate change. Combatting climate change necessarily involves a critical shift away from fossil fuels and towards clean energy, efficiency and renewable energy. Such energy resources are inherently distributed and resilient, which makes them naturally compatible with -- and their benefits maximized by -- microgrids. Thus with efficiency and renewables as part of a microgrid electricity architecture, you don't have to choose between mitigation and adaptation. You can have both. You can have your cake and eat it, too.
Microgrids for mitigation
The University of Texas at Austin is home to the nation's largest microgrid, clocking in at 140 MW. Aside from its magnitude, the facility is also legendary for its efficiency and GHG track record. The campus's district energy system, which provides heat, power and chilled water, runs at 87 percent efficiency and has managed to bring its GHG emissions below its 1977 output (most countries and companies with GHG goals are targeting 1990 levels). The university has accomplished all of this while maintaining 99.9998 percent reliability in service (yes, that is five 9s). When you ask Juan Ontiveros, director of utilities and energy management for the university, how it was done, he'll tell you, "One word: efficiency."
Energy efficiency is not only the most inexpensive way to reduce GHG emissions; it is also the most effective. It is often easier to save energy than generate more energy; a "negawatt" is often cheaper than a megawatt. When building a microgrid, energy efficiency is always the first step, because it reduces the total amount of generation that will be required to support the system.
Once you've built an efficient system, distributed renewable energy assets such as solar PV, small wind and energy storage, such as batteries, easily can be integrated into a microgrid with today's technologies. These energy sources can offer significant greenhouse gas reductions as they displace fossil-fuel-burning centralized power plants and bring electricity generation closer to the loads where the electricity is actually used. Co-locating electricity sources with the loads they serve improves the entire efficiency of the system, by avoiding transmission losses.
In addition to a significant emissions reduction benefit, renewable energy assets can decrease the total lifetime costs of the system when incorporated into a microgrid, as already has been demonstrated by many island and rural communities across the world.
Smart grid controls take microgrid performance one step further. These controls give the microgrid operator the ability to monitor and control the loads and sources combined in the microgrid, to ensure the system operates with maximum efficiency and reliability. These controls provide visibility over system performance, and allow the operator to remotely, or in some cases, automatically reduce loads or increase generation in response to changing system conditions.
Microgrids for adaptation
In a future with higher temperatures, less water, more frequent and severe wildfires and more extreme weather events, microgrids can provide unparalleled reliability and resilience. The success stories of microgrids surviving extreme weather events are flooding the headlines.
San Diego Gas and Electric (SDG&E) has partnered with the Department of Energy and the California Energy Commission to build the Borrego Springs Microgrid. This vulnerable portion of SDG&E territory lies in the remote northeast corner of its service territory, at the end of a single transmission line, in an area prone to wildfires. In order to provide better service to this territory while also protecting the greater SDG&E grid, the utility has assembled a microgrid that incorporates distributed solar PV, distributed energy storage, community and utility-scale energy storage, smart controls, an advanced Outage Management System and microgrid capabilities. In the event that SDG&E needs to isolate Borrego Springs due to a wildfire or other system threat, the community has a diverse mix of energy assets, which give it the ability to stand on its own. It is, in many ways, a textbook deployment of a microgrid -- integrated with the macro-grid normally, able to self-sufficiently island when necessary, powered by portfolio of distributed and largely renewable energy resources.
In areas where water shortages threaten local water resources, the opportunity to integrate renewable energy resources into local infrastructure is just as compelling. Most distributed renewable energy assets are far less water intensive than centralized thermal plants, such as coal. Wind and solar require no water to generate electricity; fuel cells, biomass powered generators and combined heat and power plants all can be optimized to use far less water than the alternatives -- a critical advantage for communities where water resources are scarce and droughts are likely to become more persistent.
Where severe storms threaten communities, microgrids can ensure continuity of power to critical infrastructure such as hospitals, schools and fire stations. In New York City, the NYU campus was a beacon of light amidst the darkness of lower Manhattan during Superstorm Sandy. The university has a microgrid, which allowed it to maintain heat and power to the campus throughout the storm. The State of Connecticut equally has embraced this opportunity in the wake of several severe winter storms that left portions of the state without power for several days at a time. The state has provided $18 million of funding to design and build microgrid capabilities for nine sites providing service to critical infrastructure such as police and fire stations.
Microgrids, macro solutions
A number of economic and policy hurdles still make microgrids a tough sell for most utilities and many companies. Even so, Navigant Research forecasts the global microgrid market to grow from under $10 billion this year to more than $40 billion annually in its average scenario. Meanwhile, a growing segment of campuses and communities are finding a way to make microgrids work for them, a topic we'll explore in a forthcoming blog post.
And with the latest IPCC report throwing even more fuel on the urgent fire that is global warming, microgrids become an even more attractive solution as a way to both mitigate and adapt. Climate change need not become a climate apocalypse, and microgrids can help us chart a path to a brighter energy future.