“The Grid’s Great Balancing act”^ – status in California and China


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It’s no secret that there will be significant challenges to achieving a clean energy future where a large percentage of society’s energy comes from renewable resources such as solar and wind.  Many of these challenges relate to the fact that solar and wind are variable and sometimes intermittent generators– they only produce electricity when the sun is shining and the wind is blowing.  Thus, the amount of electricity supplied by these resources is often out of sync with the demand for electricity, an issue that gets worse as solar and wind achieves a larger percentage of a region’s generating capacity. In order to deal with the imbalance with supply and demand, a combination of three actions are often taken:

  1. The price of electricity decreased. Sometimes, electricity prices can even go negative, with a state like CA having excess electricity paying states like Arizona to take the extra electricity off their grid (see article below).
  2. Conventional power plants, such as natural gas plants, are turned off/on to help balance demand and supply.
  3. Excess electricity from solar and/or wind is curtailed, meaning the connection between the solar panel or wind turbine and the grid is cut, and the electricity is wasted. (free electricity!).

In California, where almost 14% of its electricity was obtained from solar in 2016, this grid balancing act is already becoming extremely challenging, as discussed in a recent LA Times article that provides a lot of useful stats and discussion:


In China, which is the world leader in solar panel production and increasingly installing large amounts of solar power plants itself, the imbalance between electricity supply and demand is become especially acute in provinces where transmission of electricity to the large population centers is highly inadequate.  According to the article below, curtailment rates of solar-generated electricity are often 30% or higher!:


While improvements to the grid (e.g. smart grid technologies) and demand-side management can go a long way to help alleviate some of the issues involved with balancing electricity supply and demand, there is a limit to how much they can help—especially in a future where solar and wind generate 50% or more of a region’s electricity.  In this case, many studies agree that low-cost and scalable energy storage technologies are crucially important.   Batteries are one option, and have the benefit of high round trip efficiencies, but electrolyzer technologies that convert electricity into storable chemical fuels are another option.   Electricity-to-fuel technologies such as the ones we work on in our lab also represent a huge opportunity because fuels can be used for many energy applications and sectors that are not currently very reliant on electricity.  The flexibility and storability of fuels thus make them highly attractive 1.) for their ability to utilize low-cost or free electricity, and 2.) their ability to impact many different energy use sectors (transportation, industrial/chemical, agriculture, commercial) that are predominantly reliant on fossil-fuels at this time.

^credit: the term “The grid’s great balancing act” has been often used by Prof. Cory Budischak at Delaware Technical Community College. A more detailed analysis of a future scenario in which  99.9% of the electricity is provided by solar and wind can be found in a paper that he published a few years ago in J. Power Sources:


Hydrogen in Japan, Australia, and the US

There were a couple of recent articles on the growing hydrogen fuel cell vehicle (HFCV) market:

  1. Japan is investing heavily in it’s hydrogen infrastructure. With 80 H2 refueling stations already installed, Japan plans to increase that number to 160 stations supporting 40,000 HFCVs by 2020 when it will host the summer Olympics: https://www.eenews.net/stories/1060054777
  2. In the US, HFCVs are currently confined to California, which currently has 30 fueling stations, with plans to expand to 100 stations by 2020.  However, as reported in this recent New York times article, H2 fuel stations will start appearing in the Northeast between New York and Boston later this year, with several planned for the greater NYC area: https://www.nytimes.com/2017/05/18/automobiles/wheels/first-came-the-hydrogen-cars-now-the-refilling-stations.html?_r=0
  3. In all future hydrogen markets, infrastructure can be a limiting factor because it can be very expensive to build new stations, piping networks, and H2 generation plants to support HFCVs. In a renewable energy future where H2 is produced by water electrolysis driven by energy from wind and solar, a challenge is building this infrastructure that links remote generation sites with lots of solar and wind to densely populated areas where most of the demand will be.  In Australia, where there is ample space, sunlight, and wind, there has been discussion of becoming an “hydrogen exporter”, where domestically generated H2 will be shipped as liquid Hydrogen to various locations around the world in H2 tanker ships like the one shown in the rendering below: https://www.theguardian.com/sustainable-business/2017/may/19/how-australia-can-use-hydrogen-to-export-its-solar-power-around-the-world

Australia and Japan signed a deal in January 2017 to ship liquid hydrogen in bulk from Victoria, in what will be a world first. A pilot project is expected to start in 2020. Supplied artist’s impression of a liquid hydrogen carrier from ship-builder Kawasaki Heavy Industries.

Artist’s rendition of a tanker that will ship liquid H2 from Australia to Japan as a part of a deal between those two countries that will begin a pilot project in 2020. Image source is the above cited article in the Guardian.

More Solar PV Installed in US in 2016 than Any Other Electricity Source


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In a preview of a soon-to-be released annual report from the Solar Energy Industries Association (SEIA) and the GTM research, it has been reported that the electricity generating capacity of solar photovoltaic (PV) installations added to the US electrical grid in 2016 was higher than any other type of electricity generating technology. 39% of all new electricity capacity, equivalent to around 14.6 GW, was added in 2016, a 95% increase from 2015. Together, new solar and wind installations comprised 65% of all new electricity generating capacity in the US, reflecting the fact that the costs of solar PV installations have been cost competitive with traditional sources across much of the US.

As the price of electricity from solar PV continues to drop, this creates a huge opportunity to use electrochemical technologies to convert low-cost, carbon-free electricity into storable chemicals and fuels.


Plot of new electricity generating capacity in the US by year and type of technology. Source: Source: GTM Research / SEIA U.S. Solar Market Insight Report

An Update on H2 Fuel Cell Cars (and Trucks!)


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This recent article gives a nice summary of the state of H2 fuel cell vehicles in the U.S. and around the world with a focus on describing plans by a company out of Utah (Nikola) to develop a nation-wide H2 refueling network for hybrid H2/electric tractor trailers or semis:


You can see a map of the approximate locations of the planned fueling stations here. “Big rigs” are an exciting opportunity for H2 fuel cells because their larger size (fuel tanks) can be leveraged to give them a long range (distance traveled between fueling), and unlike an average private vehicle, it’s more common for a truck to a few well-defined routes. Thus, an early fleet of trucks can get by on fewer fueling stations.  Importantly, an analyst at the Union of Concerned Scientists notes in this  article that although big rigs only make up 7-10% of the vehicles on the road, they consume 25% of the fuel.

Although the H2 refueling network in the US is currently confined to California, the article above reports that a network of stations will soon be installed in the Northeast, and points out that extensive systems are in place or being built in other countries in the world like Denmark, Japan, and Germany.


Tipping Points for Solar Energy


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Below is a recent article in Bloomberg that has a bunch of good facts about the state of solar energy. Among them:…..

-“The world …. is adding more capacity for clean energy [solar & wind] each year than for coal and natural gas combined”

-“it’s likely that the total amount of solar photovoltaics added globally [in 2016] will exceed that of wind for the first time”

-“Half the price of coal”- It is noted that a record deal on a PV plant in Chile signed in August of this year came in at $29 /MW-hr – “roughly half the price of competing coal power “.

Here’s the link to the full article: https://www.bloomberg.com/news/articles/2016-12-15/world-energy-hits-a-turning-point-solar-that-s-cheaper-than-wind

World Energy Hits a Turning Point: Solar That’s Cheaper Than Wind

Cover story on Artificial Photosynthesis in c&en

The cover story for the most recent issue of Chemical and Engineering News (c&en) wason  solar fuels (aka artificial photosynthesis systems), and includes a nice overview of approaches that researchers are taking in this field: (the story starts on pg. 32):


Image result for "Will the artificial leaf sprout?"


Solar (and Coal) Power in India


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India has some very ambitious targets set for deployment of solar technology for 2022 and 2030.  At the same time, it is currently one of the biggest coal users in the world. Thus, India has huge potential to reduce its (projected) emissions, and it will be interesting to watch how these dynamics play out in the coming years.:

India wants to become a solar superpower, but its dependence on toxic coal says otherwise

H2 production vs. CO2 reduction


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Here is a recent viewpoint article published in ACS Energy Letters discussing the merits of using solar energy (or solar-derived electricity) to 1.) split water for H2 production, or 2.) reduce CO2 into liquid hydrocarbon fuels:


There is a lot of active research ongoing for both of these pathways, so this is an important discussion to be having.

The article nicely articulates the reasons for not performing CO2 reduction from CO2 captured from coal fired power plants.  However, there are other sources of CO2 as well, such as cement plants, or  capturing CO2 directly from air (so-called negative emissions) as discussed in this article:




Recent EES article on 3D printing and Electrodeposition of Electrolyzer components

We commonly use 3D printing in our lab for making (photo)electrochemical cells and reactors, and electrodeposition for depositing electrocatalytic materials.

Bridging both of these areas is a a recent paper in Energy & Environmental Science (EES) where researchers electroplated Nickel onto 3D printed PLA flow field plates to be used in polymer electrolyte membrane (PEM) electrolyzers:


Highlighting a commonly cited advantage of 3D printing, these researchers show the benefit of rapid prototyping that is made possible by 3D printing.

Mass balance on biofuels


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Here is a recent summary article on a recent life cycle analysis (LCA) study comparing CO2 emissions associated with biofuels (e.g. corn ethanol) to CO2 emissions from gasoline:


The full study was just published in the journal Climatic Change and is titled “Carbon balance effects of U.S. biofuel production and use”: