The Uncertain Future of Large Scale Solar Thermal Power Plants

(3BL Media/Justmeans) - Last week, I wrote about my visit to the Shams-1 hybrid thermal solar-natural gas plant in Abu Dhabi. This 100MW plant, which combines concentrated solar power (CSP) with natural gas, is capable of generating power around the clock. The plant’s technical support manager, Abdulazoz Al Obaidli, said that it was unclear whether more plants like this one would be built, seeing as how new solar photovoltaic plants were challenging this technology on both price and efficiency. Improvements could also be realized with this approach, but it’s unclear, especially given the long lead times for building a plant like this, what the comparison will be down the road.

While CSP plants are basically steam plants with mirrors, photovoltaics are semi-conductors which have a tendency to follow something called Moore’s Law that has seen performance doubling and costs dropping at regular intervals like clockwork. And though we tend to think of PV in terms of small rooftop installations, there are, in fact 19 PV plants of 100MW or more, the largest being the Topaz Solar Farm in San Luis Obispo, CA, which weighs in at 550MW.

While the matter is far from settled, there are a number of other challenges facing CSP, sometimes called solar thermal plants, which use the heat of the sun to produce steam, unlike photovoltaics that convert sunlight directly in electricity. The CSP plants, given the thermal mass of fluids in the system, do produce more stable power and are thus better suited to baseline applications.

A Visit to Shams-1: Abu Dhabi's Unique Solar CSP Hybrid Power Plant

(3BL Media/Justmeans) - One of the first questions I asked upon arriving in Abu Dhabi, a very modern city in a very oil-rich country, with a very progressive stance towards renewables, was, why? Besides the obvious fact that unlike some other people, they recognize the fact that their oil won't last forever, and they want to participate in energy after it runs out. But there's something else, too. They would like to see an orderly transition that allows them to steward their resource to make as much out of it as they can.

A great example of that is the Shams-1 hybrid solar power plant, which is located 120 km southwest of Abu Dhabi.
Shams is a joint venture between Masdar of the UAE, which contributed 60%, Total, of France, (20%), and Abengoa Solar of Spain (20%).

This unique plant uses a combination of concentrating solar power (CSP) and natural gas which adds a bit to the cost, but gives it some unique capabilities, including the ability to produce power anytime at all, even at night.

During ordinary operation, the parabolic mirrors, of which there are over 258,000, that cover an area of roughly 2.5 square kilometers, track the sun and focus its rays on a pipe containing an oil-based heat transfer fluid (HTF), which heats it to around 400 degrees Celsius. The heated fluid is then used to boil water, the result of which is used to drive a fairly conventional steam turbine.Natural gas can produce up to 50% of the plant's rated capacity, though under full sun, it contributes only 18% of the energy input. This is done by superheating the HTF to 530 Celsius, a point at which the turbine runs more efficiently. This combination produces 100 MW, enough to supply 20,000 homes here. The power is being supplied to the Abu Dhabi Electric Company through a 25 year power purchase agreement.

Earth Day 2014: Where Do We Stand?

(Justmeans/3BL Media) - As I sat at my desk trying to find a suitable subject for the 44th annual Earth Day, I scoured my Twitter feed and my inbox looking for the story that would capture the essence of where we stand right now in our battle to save the planet. While there is plenty of interesting news coming out every day, it is so strongly divided into good news and bad news, that there is no way that one story can possibly sum it all up.

Take the IPCC, for example. Earlier this month, Working Group II, responsible for studying the impacts of climate change issued a frightening report that was hard to view as anything other than a call to action. The impacts are already occurring, chain reactions have been set in motion, and we can expect things to get quite bad, especially if we don’t begin to substantially escalate our efforts to curb emissions. IPCC chairman Rajendra K. Pachauri, said. “nobody on this planet is going to be untouched by the impacts of climate change.” This will be particularly true for those most vulnerable, including low-lying and poorer countries, as well as the poorest residents of all countries. But the same report (which still is yet to be officially published) also said that the economic cost of a 2.5 degrees Celsius rise is going to be somewhere between 0.2 and 2.0% of the global GDP, far less than expected. That might be considered good news, though it might also encourage politicians to defer action on the bad news contained in the report.

Then there is the question of natural gas. There can be no doubt that the large-scale replacement of coal with natural gas for electric generation purposes, accelerated by the drop in natural gas prices, has led to a dramatic reduction in carbon emissions. Coal has been the largest source of carbon pollution, and natural gas emits only half as much carbon. Unfortunately, this boom in natural gas production has come to us via hydraulic fracking, a method that is fraught with problems of its own, ranging from earthquakes, to sizable methane releases (methane is twenty times more potent than CO2 as a greenhouse gas), to contamination of drinking water. These concerns are substantial enough for the National Renewable Energy Lab to declare natural gas less climate-friendly than diesel fuel, though still better than coal. Producers are also pressing to increase natural gas exports, which is not only bad for the environment, but will also raise gas prices here in the US.

Commercial Scale Cellulosic Ethanol Arrives—Finally

The question of biofuels as an energy source has probably generated more heat than light. It has also powered a great many vehicle miles that otherwise would have been powered by gasoline. Whether you consider that a good thing or a bad thing will likely determine your position on the issue.

Conservatives dislike biofuels because they represent a large government program and because they pose a genuine threat to one of their biggest supporters, the oil industry. Liberals dislike them because they are the legacy of George W. Bush and because of their inherent distrust of industrial agriculture which benefits greatly from the commitments that have been made.

While these facts are all true, they are more distractions than anything to do with the crux of the matter. Clearly, the issue is complex enough to merit an entire book, but let me just focus your attention on what is happening right now.

The oil industry lobby works tirelessly to protect the hundreds of billions of dollars of profits that their sponsors receive every year. Sensing an opportunity in the public’s combination of confusion over and dislike of ethanol, they have gone on the offensive, asking the EPA to back off on the amount of ethanol mandated under the Renewable Fuel Standard (RFS). The EPA has listened and as of December, they have reduced the amount of ethanol that must be produced by 1.34 billion gallons, a reduction of roughly 8%. Further greater reductions of as much as 40% are on the table and will be decided in June.

While it’s true that there is much to dislike in the corn ethanol program, including its energy intensity, competition with food, and relatively small net energy benefit, not to mention the fact that we are now producing far more gasoline domestically via fracking and other questionable means, there is a sustainable gem at the heart of the program. That gem, known as cellulosic ethanol, uses non-food sources, such as agricultural residue, trash, wood chips and forest trimmings to make fuel. These fuels represent a far better ecological bargain than corn or any other food crop. The reason we went with corn at first was because we know how to grow lots of corn really well, and we’ve known how to make alcohol out of corn since the days of the moonshiners. The reason we didn’t start out making fuel out of wheat straw, or corn stalks or other crop wastes was because we didn’t know how. Many years and millions of research dollars later, studying everything from enzymes to embryogenic cell cultures, cellulosic ethanol is on the verge of becoming prime time. This could turn out to be a really bad time for the government to withdraw its support. Doing so now could be like throwing out the baby with the bath water.

Abengoa Bioenergy, a Spanish company, is investing $500 million in a plant in Kansas that will produce 25 million gallons of ethanol per year from crop wastes. The plant, which will be operational next month, will be powered by a 21 MW electric generator that will also be powered from biomass. That plant will be followed later in the summer by a plant of similar size in Emmetsburg, Iowa by the South Dakota-based ethanol producer Poet, in partnership with the Dutch company Royal DSM. Those two plants will be followed by a 30 million gallon plant DuPont that is underway in Nevada, Iowa, that will also be using corn waste.

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