Reverse Power Flow: How Solar+Batteries Shift Electric Grid Decision Making from Utilities to Consumers

Date: 17 Jul 2018 | posted in: Energy, Energy Self Reliant States | 0 Facebooktwitterredditmail

For 100 years, most decisions about the U.S. electric grid have been made at the top by electric utilities, public regulators, and grid operators. That era has ended, and our report details how the collective impact of individual consumers installing solar-plus-storage reverses the flow of power on the electricity grid.… Read More

Small Ohio Town to Feature Large Distributed Solar and Storage

Date: 22 Feb 2016 | posted in: Energy, Energy Self Reliant States | 0 Facebooktwitterredditmail

Energy storage is the “next charge” for distributed renewable energy, and the small town of Minster, OH, provides a powerful illustration. Committed to building a 3-megawatt (AC) solar facility, the village’s energy department (municipal utility) was blindsided by the state … Read More

A Perfect Storm for Renewables – Episode 18 of Local Energy Rules Podcast

Date: 21 Mar 2014 | posted in: Energy, Energy Self Reliant States, Podcast | 0 Facebooktwitterredditmail

The Hawaiian utility, made local when the investor-owned utility left the business a decade ago, is surging toward 40% renewable energy in the next year, with a third of that total from customer-generated solar. Half its daytime energy will come from solar arrays by the end of 2015.

Learn more about how a cooperative utility has blown past purported technical barriers to renewable energy and pioneered energy storage to make solar a prominent part of their energy mix in this interview with Jan, recorded via Skype on Feb 25, 2014.… Read More

Distributed Renewable Energy as the 3rd Industrial Revolution

Date: 20 Jan 2012 | posted in: Energy, Energy Self Reliant States | 0 Facebooktwitterredditmail

I just came across an interesting interview that radio host Diane Rehm did with Jeremy Rifkin, author of The Third Industrial Revolution.  The excerpts below lay out his vision for an energy future that is decentralized and democratized. (He also notes that this vision has just emerged in the past two to four years, but we’ve been around since 1974…).

The book is organized around five pillars of the third industrial revolution:

Pillar one, renewable energy. Pillar two, your buildings become your own power plants. Pillar three, you have to store it with hydrogen. And then Pillar four…the internet communication revolution completely merges with new distributing energies to create a nervous system…Pillar five is electric plug-in transport…

when distributed Internet communication starts to organize distributed energies, we have a very powerful third industrial revolution that could change everything…

You can find some renewable energy in every square inch of the world. So how do we collect them? … If renewable energies are found in every square inch of the world in some frequency or proportion, why would we only collect them in a few central points? …

[it] jump starts the European economy, that’s the idea. Millions and millions and millions of jobs. Thousands of small and medium-sized enterprises have to convert 190 million buildings to power plants over the next 40 years…

That’s the vision: a decentralized energy system can be democratized with local ownership, spreading the production of energy and the economic benefits as widely as the renewable energy resource itself.


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Some Skepticism on Solar Thermal Power’s Storage Potential

Date: 3 Jan 2012 | posted in: Energy, Energy Self Reliant States | 2 Facebooktwitterredditmail

Yesterday New York Times reporter Matt Wald had a piece on the role of energy storage in supporting the expansion of renewable energy.  However, his specific focus on solar thermal power generation overlooks the potentially high costs of relying on … Read More

With Electric Cars, U.S. States Can Boost Energy Self-Reliance

Date: 4 Oct 2011 | posted in: Energy, Energy Self Reliant States | 4 Facebooktwitterredditmail

The U.S. Northwest could get an additional 12 percent of its electricity from local wind power if 1 in 8 of the region’s cars used batteries. 

That’s the conclusion of a new study from the Pacific Northwest National Laboratories investigating how electric vehicles can help smooth the introduction of more variable renewable energy into the grid system.

The study examines the Northwest Power Pool, an area  encompassing roughly seven states in the Northwest.  With around 2.1 million electrified vehicles, the grid could support an additional 10 gigawatts of wind power.  With electricity demand from those seven states of about 250 billion kilowatt-hours (kWh) per year, the additional 10 gigawatts of wind would provide 12 percent of the annual electricity demand (roughly 30 billion kilowatt-hours per year).

The results are no doubt applicable to other regions of the country.  In fact, at least 33 states have enough wind power to meet 10 percent or more of their electricity needs and if the same portion of vehicles (13%) were electrified in those 33 states, it would allow them to add a collective 100 gigawatts of wind power, meeting nearly 14% of their electricity needs. 

Northwest Power Pool

In the long-run, a fully electrified vehicle fleet would theoretically – just do the math! – provide enough balancing power for a 100% renewable electricity system.  And since the large majority of those vehicle trips would be made on batteries alone, it would be a significant dent in American reliance on foreign oil for transportation. 

Further reading: learn a bit more about electric vehicles helping wind power in Denmark, too.

Hat tip to Midwest Energy News for the original story.

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Does Energy Storage Compensate for Thirsty Concentrating Solar Thermal Power Plants?

Date: 28 Jul 2011 | posted in: Energy, Energy Self Reliant States | 1 Facebooktwitterredditmail

Concentrating solar thermal power has promised big additions to renewable energy production with the additional benefit of energy storage.  But with significant water consumption in desert locations, is the energy storage benefit of concentrating solar enough to compete with the dramatically falling cost of solar PV?

In May, I compared the water consumption of fossil fuel power plants to various solar technologies, noting that wet-cooled concentrating solar thermal power (think big mirrors) uses more water per megawatt-hour (MWh) than any other technology.  The following chart, from the earlier post, illustrates the amount of water used to produce power from various technologies. 

Water consumption can be cut dramatically by using “dry-cooling,” but this change increases the cost per kilowatt-hour (kWh) of power generated from concentrating solar power (CSP).  In the 2009 report Juice from Concentrate, the World Resources Institute reports that the reduction in water consumption adds 2-10 percent to levelized costs and reduces the power plant’s efficiency by up to 5 percent. 

Let’s see how that changes our original levelized cost comparison between CSP and solar PV.  First, here’s the original chart comparing PV projects to CSP projects, with no discussion of water use or energy storage.

To make the comparison tighter, we’ll hypothetically transform the CSP plants from wet-cooled to dry-cooled, adjusting the levelized cost of power.

Using the midpoint of each estimate from Juice from Concentrate (6 percent increase to levelized costs and 2.5 percent efficiency reduction), the change in the cost per kWh for dry-cooling instead of wet-cooling is small but significant.  For example, all three concentrating solar power projects listed in the chart are wet-cooled power plants.  With a 6% increase in costs from dry cooling and a 2.5% reduction in efficiency, the delivered cost of electricity would rise by approximately 1.7 cents per kWh.

The following chart, modified from our earlier post, illustrates the comparison.

With the increased costs to reduce water consumption, CSP’s price is much less competitive with PV.  In our May post, we noted that a distributed solar PV program by Southern California Edison has projected levelized costs of 17 cents per kWh for 1-2 MW solar arrays, and that a group purchase program for residential solar in Los Angeles has a levelized cost of just 20 cents per kWh.

In other words, while wet-cooled CSP already struggles to compete with low-cost, distributed PV, using dry cooling technology makes residential-scale PV competitive with CSP.

But there’s one more piece: storage.


While Nevada Solar One was built without storage, the PS10 and PS20 solar towers were built with 1 hour of thermal energy storage.  Let’s see how that changes the economics. 

To make the comparison comparable, we’ll add the cost of 1 hour of storage to our two PV projects, a cost of approximately $0.50 per Watt, or 2.4 cents per kWh.  The following chart illustrates a comparison of PV to CSP, with all projects having 1 hour of storage (Nevada Solar One has been removed as it does not have storage). 

When comparing CSP with storage (and lower water use) to PV with battery storage, we have a comparison that is remarkably similar to our first chart.  Distributed PV at a commercial scale (1-2 MW) is still cheaper than CSP, but residential PV is more expensive. 

Even though dry-cooled CSP competes favorably on price, it still uses much more water than PV.  That issue is probably why many solar project developers are switching from CSP to PV technology for their large-scale desert projects.

Without a significant cost advantage, the water use of CSP may mean an increasing shift to PV technology.

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U.S Grid Can Handle Lots of Solar PV with Low Integration Costs

Date: 10 Mar 2011 | posted in: Energy, Energy Self Reliant States | 0 Facebooktwitterredditmail

A state such as New York should be capable of absorbing and benefiting from well over 7 GW of high- value PV without having to incur significant integration costs beyond the cost of PV itself, further noting that the storage sizes involved could well be met with a smart deployment of interactive plug-in transportation...the low-cost penetration potential is large enough to allow for the development of a considerable localized, high-value PV generation market worth 100’s of GW in the US.

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