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Posts Tagged ‘coal’

The Role of Storage with Variable Energy Sources Like Wind and Solar

by November 8, 2011

In a recent post, I asked What’s Going To Happen To Your Vehicle’s Lithium Battery At the End Of Its Life? One of the options discussed in the NY Times article about the fate of batteries that sparked my post was as a means for storing electricity generated by wind turbines. A couple of other recent articles about energy storage caught my eye—both related to wind energy.

Why might storage play a key role in a grid that has a lot of wind turbines?

In early October, Mark Ahlstrom, the CEO of WindLogics, gave an excellent presentation as part of Frontiers in the Environment series at the U of MN’s Institute on the Environment (view the video here). He explained how our variable demand for electricity over the course of a typical day is met by a range of generation sources, from base load to “peakers.” Base load is met by nuclear, coal, and hyrdo—depending on location. Base load plants are meant to run 24/7, and adjustments to their output need to be scheduled well in advance. On the other end of the spectrum are peakers, which are small electrical generators that can be turned on with little notice and do not need to run for a minimum period of, say, a day. The figure below is based on a slide from Ahlstrom’s slides.

ahlstrom-sys-load-combo

Ahlstrom went on to explain how things get interesting when a substantial amount of wind generators are added to the mix. In the figure below, the bright green line represents the reduced daily load that results by adding a number of wind turbines to this hypothetical typical energy demand. He goes on to explain how the rest of the electricity generators need to adapt to this new load curve, which can have more spikes and other challenges, such as a faster ramp-up in the early morning hours—challenges that the current energy system wasn’t set up to tackle.

ahlstrom-sys-load-combo-2

Here’s a good piece by the ClimateWire group that landed in the NY Times: Fickle Winds, Intermittent Sunshine Start to Stress U.S. Power System. It dives into detail about the policy challenges that blending intermittent energy sources with our traditional electrical generation system.

Back to storage. A recent piece in the NY Times described how Batteries at a Wind Farm Help Control Output. In the largest battery installation connected to the grid in the U.S., they’ll use over a million batteries to provide storage for a few minutes of generated electricity from a large wind farm in West Virginia. The idea is that this stored electricity can be fed into the grid to help smooth things out when output from the wind turbines drops off momentarily. It is not designed to even out longer periods when the wind is calm. Significant storage on the time scale of hours and possibly days would most likely require a solution such as pumping water uphill or compressing air when the wind blows, and then using this stored energy to run a generator when the wind is quiet (here’s a project underway to study pumped hydro in conjunction with wind farms in northern Minnesota). There may also be options to store electricity in electric vehicles integrated with a smart grid of the future.

Finally, another NY Times piece that gave me some pause had to do using water heaters and electrical space heaters to store excess electricity brought about in part from excessive winds in the Pacific Northwest. The idea is that automated, shorter-term storage of excess electricity in homes that already have electric hot water heaters and heat with electricity could bleed off excess electricity pouring into the grid during storms when wind generators are running at maximum output (note that the situation was further complicated because hydropower operators were unable to reduce output from their generators for fear of creating conditions that might kill fish).

At a gut level, this strikes me as a good way to avert disaster, but probably not a great strategy from an energy efficiency standpoint. My sense is that using electricity for water heating and space heating is not nearly as efficient as, say, natural gas. The standard reason for arguing this point is that the efficiency of traditional energy plants is much less than 50%, whereas a high-efficiency hot water tank can exceed 90%. However, maybe this standard reasoning needs to be updated in a situation where electricity comes from wind or solar. This is a topic that merits further consideration.

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What A Mouthful: Eating Through the U.S. Energy Mix In 60 Seconds

by April 26, 2011

uncle_sam_stopwatch

Energy sources in order from 12 o'clock as shown in Uncle Sam's Dinner video: natural gas, biomass, coal, nuclear, hydro, solar, wind, and oil.

A recent post by David Roberts on Grist.org demonstrated the value of explaining a rather simple concept about our energy system: the mix of our energy sources. In Robert’s post, he pulled out data from Black & Veatch’s Energy Market Perspective analysis on the energy sources for U.S. electricity generation, comparing the mix in 2011 to that projected for 2035.

This post made me want to take another look at the video, Uncle Sam’s Dinner, from our just-completed video contest. Specifically, I wanted to check how closely the creator, Henry Reich, had come to representing the various energy sources that make up the overall U.S. sector—not just for electricity generation. Comparing the pie chart below with the stop watch captured above, it is clear that the video is extremely accurate. See this post for the full background material on the U.S. energy sector provided to creators for this contest. (more…)

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What are the top 10 energy topics that the general public should understand?

by April 22, 2011

quora-pictureGetting a handle on the priority issues that should be included in Dialogue Earth’s upcoming Media Challenge is no small task, plus it needs to be done transparently and in an inclusive manner that ultimately builds trust.

Ten years ago there were fewer options for answering a tough question like this (refer to our History section for a description of the lengthy process used in an effort to identify 100 indicators to describe the condition and use of U.S. Ecosystems). Today, there are some powerful platforms that hold considerable promise for helping to expedite this process (see discussion in this recent post).

Today, we have launched an experiment using one of the prime Q&A platforms, Quora, to explore the viability of exploring answers to this question in an open and transparent manner. If you have an opinion, please jump over to Quora and make your voice heard. You can enter answers directly, and you can vote on answers provided by others. Here is the background material that I added to the question on Quora: (more…)

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Bringing Trustworthy Energy Information to the Table

by April 20, 2011

This opinion piece authored by Kent Cavender-Bares was published in the Pioneer Press on April 20, 2011.

‘We need all of our energy options on the table!’ So say those advocating for the removal of the legal barrier preventing new nuclear plants in Minnesota. I completely agree with the sentiment and would go a step further: We need to understand all of our energy options so we can make informed decisions about them.

Does this mean entering a cycle of unending study? No. Expert studies certainly have their important role. But they are not the weak link. Rather, what is missing is an adequate transfer of knowledge from the expert community to the rest of us regarding the multiple, unequal options available. We need translators to bring technical key points to life in a way that furthers our understanding while remaining faithful to the underlying science and technology.

The challenge in making that happen with complex, controversial topics such as nuclear energy is twofold.

First, it means traversing the gap between the language of those who understand a technology like nuclear energy and the rest of us. That is where great communicators come into the picture.

Second, it means separating trustworthy information from hyperbole. We need to be able to identify and then clearly communicate a knowledge base that is widely shared by experts drawn from across society — experts from corporations like GE and Xcel as well as academics and experts from various advocacy groups and government agencies. (more…)

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The Energy Challenge Series – Our First Concept Phase

by March 15, 2011

dialogue-earth-energy-promo-imageThrough our trials, we have found that it is best while administering our video production contests through Tongal to start out with a concept phase.  By starting the contests in this way, it gives us more opportunity to give feedback and a little bit more quality control as opposed to just allowing the producer contestants to create videos based on their interpretations of our instructions.

Also by allowing for the concept phase, we can involve the best storywriters within the creative community, many of whom do not have the resources to produce videos.  This increases overall participation, seeds our project with great concepts, and plays towards the collaborative spirit of our crowdsourcing endeavor.

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Background Information on Energy Video Pilot

by February 28, 2011

This post supports a new video contest that we are launching with partner Tongal this week on the subject of energy. This is to be the introductory contest for the forthcoming Dialogue Earth Energy Challenge, in which we expect to tackle 10 topics related to energy in 10 video contests spread out over as many months.

In that this is meant to be an introductory video, we realize it cannot do everything—especially because we are asking storytellers to limit their pieces to 90 seconds. Yet, we believe that the larger Energy Challenge needs a gateway video. It should draw people in, eventually inspiring them to click on another video or two to learn more about the details of a particular energy source, etc.

llnl_us_energy_flow_2009_smaller

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