Special Coating Improves Performance of Solar Cells

A new startup company called Brisbane Materials has created a special coating that can be applied to solar cells for a boost in performance. The company recently announced that they have closed their AUD $5 million ($5.2 million) Series A funding round lead by Southern Cross Venture Partners (SXVP), which will help bring their innovation closer to the market.

According to CEO Gary Wiseman, solar panels coated with the company`s anti-reflective material will generate 3% more electricity. However, coating products for solar panels have been around for quite some time, but they at best only deliver a performance boost of 2%. A net gain of 1% is actually quite significant in the solar photovoltaic industry, and a couple of years down the line, the new invention might actually influence cost reductions and growth in the market.

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An electron microscope reveals the structure of the new anti-reflective coating material:

Brisbane materials

Image source: Brisbane Materials

The layer named BMT AR coating is the where the innovation lies. This thin slice, only 110 nanometers thick, consists of air pockets caught between porous glass. The combination reduces reflection of light by as much as three fourths.

According to Brisbane Materials, the process that attaches the anti-reflective coating on top of the glass surface does not require high amounts of heat, as most other conventional manufacturing methods need. This will not only simplify manufacturing, but also produce anti-coating material for lower costs.

The anti-reflective coating has actually been researched at the University of Queensland in Australia since 2005, but the technology was sold to Brisbane Materials for further development. Let`s hope the new startup company succeeds and we see more of the technology in the next couple of years.

How Spinach Can Boost Efficiency of Biohybrid Solar Cells

Scientists often look at how nature has evolved in order to figure out how they can optimize technology. Sunflowers and many other plants have learned the ability to follow the sun as it moves across the horizon, which optimizes the photosynthesis and enables them to grow at a faster pace. Researchers at Vanderbilt University (VU) in Nashville, Tennessee have figured out how isolate and combine PS1, a photosynthetic protein found in spinach, with silicon typically used in solar cells.

The discovery has lead to a Biohybrid solar cell that is capable of producing significantly more power when exposed to sunlight than any of it`s other solar cell of its kind.

“This combination produces current levels almost 1,000 times higher than we were able to achieve by depositing the protein on various types of metals. It also produces a modest increase in voltage,” said David Cliffel, associate professor of chemistry at VU.

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Image credit: Vanderbilt University
An older design of the researchers` biohybrid solar cell.

The research team thinks they will be able to construct a Biohybrid  solar cell on par with mature solar conversion technologies in three years time – if the current trajectory of increasing voltage and current keeps going.

Kane Jennings, professor of chemical and biomolecular engineering at VU, holds an award from the Environmental Protection Agency that allows her undergraduate engineers to design a prototype based on their “spinach-silicon” approach. A two-foot solar panel could potentially produce 100 mA – the equivalent power that is required small electrical devices.

Zero-Down Solar Leasing for New Homes

The solar PV market has been though a lot of changes in the last couple of years. Since Solarcity introduced the model of zero-down solar leasing back in 2006 many solar providers (including SunRun, Sungevity, SunPower and Real Goods Solar) have followed suit. Third-party-ownership has become the preferred way to go solar in many of the solar states across the country. A study conducted by PVSolarReport found that 70% of all Californians now prefer third-party solar.

SolarCity announced that they have started offering zero-down solar leasing in new home communities. This means that homebuilders can integrate solar panels in their residential communities, and according to SolarCity, “homebuyers can save up to 20 percent on their energy costs from the very first day they move in”.

SolarCity solar panels for new homes
Image credit: SolarCity

EIA (Energy Information Administration) says the residential sector contributed to 20% of all carbon dioxide emissions last yearthere`s clearly a lot of potential for lowering our carbon footprint by being smarter about energy use in our homes.

A residential solar system is an excellent replacement of other carbon-based electricity sources. Thanks to federal and state incentives, solar panels also makes a lot of sense financially. One Block Off the Grid reports that the average homeowner saves over $1200 a year on electricity by going solar.

Whether or not a lease or a power purchase agreement (PPA) would be the best approach in your situation depends. As a general rule of thumb, if you can afford to pay with cash upfront, or if you can finance the solar system through a well-structured loan, then you should avoid third-party-ownership. The truth to the matter is that in terms of long-term savings, ownership beats a lease or a PPA every time.

SolarCity is offering zero-down solar leasing for new homes in Arizona, California, Colorado, Maryland, New Jersey and Oregon, and plan to expand the program to other states in the months to come.

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NREL Sets New World Record with Two-Junction Solar Cell

Scientist Myles Steiner has announced that The Renewable Energy Laboratory (NREL) has set a new world record at 31.1% for a two-junction solar cell. The research team at NREL beat Alta Devices` previous record by 0.3%.

The new solar cell consists of a layer of gallium indium phosphide on a gallium arsenide cell. Bilayer anti-reflective coating sits on the top of the cell and a reflective gold contact layer is attached to the bottom. In other words, far more costly materials than what we currently use in the highest-efficiency crystalline-based solar panels.

NREL efficiency chart

NREL`s latest chart of best research-cell efficiencies (up-to-date with the new world record) can be found here.

The new record will likely be beaten in short time. NREL is determined to get closer to the 48% efficiency goal set by Department of Energy`s F-PACE project.

Although the solar market is currently dominated by different types of crystalline silicon (90%), scientists see a lot of opportunity in other materials. Multi-junction solar cells are currently the preferred type of solar cell for applications in space. High efficiency goes hand-in-hand with space-efficiency (surface) and is therefore of higher importance than costs.

There`s a lot of things happening in the solar industry nowadays. Recently Sharp announced that they have created the most efficient solar cell to date, with an incredible 44.4% efficiency rate.

Whether or not we will ever see multi-junction solar cells in widespread use here on earth remains to see. Nevertheless, it will be interesting to follow NREL as they get closer and closer to 48%, and keep pushing the threshold of what is possible with photovoltaic technology.

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$10 Million Prize for Cheaper Solar Panel Installations

The costs of solar panels have steadily decreased over the last few years. The costs of the installation itself have pretty much stayed the same. The Department of Energy has now launched a $10 million prize for cheaper solar panel installations in an effort to lower installation costs, which are taking up an increasing amount of the total costs of residential solar power. In fact, “soft-costs”, which basically covers everything apart from hardware, is now the largest portion of today`s residential solar panel costs.

The top three solar installers that repeatedly can demonstrate that they have the capability to install solar for as little as $1 per watt (non-hardware costs) for small-scale photovoltaic (PV) systems on American homes and businesses will be declared winners of the SunShot Prize.

In order to be eligible for the prize, the solar installers will have to install 5,000 solar systems with average “soft-costs” of not more than $1 per watt, and then another 1,000 to prove that their business is sustainable. The first team to complete this task will receive $7 million, second place will receive $2 million, and third place will receive $1 million.

The prize is a smart way to bringing down the installation costs of solar panels and if successful would be transformational to the U.S. market.

Read more about the costs of solar in Solar Panels Cost
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Energy Storage and Daily Price Variations

It is not unusual that the price for electricity can vary significantly over a period of 24 hours. Daily fluctuations usually range from 100-150%. The lowest prices can be found early in the morning where it starts growing and reaches it`s highest peak shortly after noon. We also consume less energy in weekends.

Energy storage systems can take advantage of these price changes. Storing energy when demand is low and discharging the same energy when prices go up could result in a nice profit.

How is the energy stored? Let`s take a look at hydroelectricity. The potential energy in water at the height of the water storage is converted into kinetic energy (motion) when the gates open and release it downhill.

Hydroelectric storage is the same process only the other way around: Cheap off-peak electricity is bought from the power grid to pump water uphill. In other words, the electricity is stored as potential energy for later use.

This is not only profitable, but is also associated with two key benefits to the electric power system:

  1. Load-shifting lowers the effective peak demand.
  2. More power plants can act as base-load resources due to higher energy demand overnight.

 

Let`s use geothermal power plants to illustrate the second point.  There can be significant efficiency losses and costs associated with reduced output or temporary shutdown of base-load plants.

Unlike many other sustainable energy resources such as solar and wind, geothermal is outstanding when it comes to delivering a steady output of energy. This is why geothermal is a base-load energy resources.

Read Geothermal Energy Pros and Cons for more information on the benefits and downsides of geothermal power plants.

Source: U.S. Energy Information Administration

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Smart Home Reduces Energy Consumption by 88%

It has been one and a half years since Osaka Gas and Sekisui House started working together on the Smart Energy House project. They wanted to test how much energy and carbon dioxide they could save by optimizing a house to be less dependent on outside energy sources.

 

Promising Results

From July 1st 2011 to June 30th 2012, a three-person family was put in the house, and their energy usage was recorded and analyzed throughout the year. This is what they found:

According to their own numbers, power consumption was reduced by as much as 88% from 4830 kWh (average power consumption for a typical household in Japan) to 584 kWh annually.

The reduction of carbon dioxide emissions was greater. In fact, the net carbon footprint was slightly negative (-137kg) over the course of a year. As a comparison, a typical Japanese household will generate about 4 770 tons of CO2 equivalents.

 

The Smart Energy Home

So how did they do it? What exactly is a smart energy home? The success of the Japanese home in this study was mainly caused by these few factors:

 

Solar Panels

A 5.08 kW solar panel system was incorporated in the home. Sunny days meant a constant stream of clean electricity generated from solar energy.

Read more about the advantages and disadvantages of solar panels in Solar Energy Pros and Cons.

 

Lithium Ion Batteries

At days when the solar panels outputted an excess amount of electricity, more than what the family was able to consume, the surplus was stored in 3.5 kWh lithium ion batteries for later use.

 

Natural Gas Fuel Cell

There will be days when there is neither enough sun to generate electricity with the photovoltaic system or energy left in the batteries. This is when the natural gas fuel cell comes in. It allows for a quick and reliable way to meet energy demand.

 

Home Energy Management System (HEMS)

The home energy management system ties the solar panel system, the batteries, and the natural gas fuel cell together and makes sure that everything runs smooth and energy efficiency is good.

 

Not Finished Yet

The first year of the Smart Energy Home project is finished, but will keep going for at least through 2014. The team will in the coming months focus on incorporating electric cars, pure solar heating and better balancing of the battery system. The homes is scheduled to go on the market in 2015.

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Grid Energy Storage – Craig Shields Interview

We expect to see more and more renewable energy sources such as solar and wind in the coming years. These are highly unpredictable sources of energy. When the wind is blowing and the sun is shining, we have a surplus of energy that needs to be stored for days where the consumption exceeds the amount of energy being produced.

Craig Shields is the author of Renewable Energy – Facts and Fantasies: The Tough Realities as Revealed in Interviews with 25 Subject Matter, the #1 best-selling energy book on Amazon.com. Craig is also the editor of 2GreenEnergy and has more than 25 years of experience as a marketing consultant. We decided to interview him to find out what he thought about the future in utility-scale grid energy storage.

 

What do you think are the most promising technologies to store utility-scale energy at this time?

It is a function of what technology we are using to generate the energy in the first place. For instance, if we get heavy into solar thermal energy, we need to utilize entirely different storage methods.  This energy is heat – not electricity as it is in for instance wind turbines or PV-cells.

We can store heat energy a lot less expensive than electrical energy.  You simply heat up a substance to a couple thousand degrees and you use that heat energy, as you need it. Molten salt heated by solar energy is a good example of this.

So if we were heavy into concentrated solar power (CSP), that would be a direction we want to go in, as opposed to if the world was covered in PV-cells.

The vast majority of energy storage right now is pumped hydro. In other words, taking water from a certain elevation and pumping it up to a higher elevation, and extracting the energy from the water coming back down whenever you need it.

Pumped hydro is obviously not portable and you can only use it at certain topographies. If you don’t have a natural change of elevation it would be horrifically expensive.

Similarly, I’m not a huge believer in compressed air (CAES). There are two implementations of this technology on the planet today and I think there is a reason for that. The choice of caverns is very specific for the rate at which you need to charge and discharge. You pay a huge penalty in terms of thermodynamic efficiency if you have the wrong cavern for what you’re doing. The world does need more implementation and testing of this technology, but I’m not sure if it will be a good long-term solution.

 

What about batteries? People say that zinc-air might be suitable for storing energy on the grid. Is this true?

Batteries are ridiculously expensive at the moment, but that is not going to remain the case forever.  Breakthroughs in zinc-air battery technology might get the prices down to competitive levels in the near future. You will be able to deploy batteries on grid-scale if you lower the price and this promises to do just that.

This technology has been through 5000-6000 cycles of charges and discharges in the laboratory, and has fantastic characteristics in everything that is related to grid scale. For instance, you don’t really care how big or heavy it is if it where to be implemented on the grid, as you certainly would for electrical transportation.

Electric transportation is another wild card in all of this. We have 230 million cars and trucks on the roads in the United States. If we replace a significant number of those to be driven by electricity, and tie them into the electrical grid system, the equation changes completely.

I am a believer in zinc-air. We have had air-batteries trotted out every couple of years since I was a little kid, so I’m skeptical as anybody should be, but I believe and trust the people developing this technology.

 

What do you think about hydrogen as an energy carrier? Do you see hydrogen as a part of our energy storage system in the future?

The beauty about hydrogen is that it is portable. However, the delivery infrastructure itself has not been developed. There are 3.5 billions square miles in the continental United States. In addition to this, electrolysis of hydrogen itself is fairly inefficient. By the time you split the water and pull it through a fuel cell, you actually consume 3-4 times more energy, as you would through some other means, for instance charging and discharging a battery. “People keep talking about hydrogen, but I have no idea why. I really don’t see it.”

The cost of batteries is going to come down to the point that you can put 50 kWh in an automobile at a reasonable price, which gives you a couple of hundred mile range. I don’t see why people want to drive more than 300 miles a day. I don’t think we are more than 10-12 years from that, so why should we invest trillions of dollars in an entirely new fuel delivery infrastructure? I don’t see it.

There are other types of liquid fuels we are trying to develop. Everybody is talking about algae biofuels. There are breakthroughs that can come further down the line, but biofuels has a limited use in my estimation.

Having said that, I am a believer in synthetic fuels. There is a company called Doty Wind Fuels that has made enormous breakthroughs in this subject. You can take off-peak wind or any source for that matter, and generate hydrocarbons that are high quality diesel or high-octane gasoline. That’s basically taking wind energy that otherwise would not be used and storing it for times when needed.

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How far are these methods from being implemented on the electrical grid to store energy?

There is no good answer for when utility scale energy storage will be implemented for the following two reasons:

First you have the technology issue. Although many of these technologies looks promising on paper and some perform well under testing, we could be decades away from being able to implement them on the electrical grid.

Then there are the economical and political issues. If we want utility scale energy storage in the United States we have to create a political and economical infrastructure that provide incentive. Who is going to pay for this? It’s hard to imagine one group taking the responsibility for something everyone will benefit from. At least in the United States that’s a very tricky question.

We are in an election year in the United States. We protract and drama our choosing of a president like no other country on earth. You can imagine the rhetoric that goes on in a subject as large as energy.

I am still dumbstruck when I hear people say that they don’t believe in basic science. In other words, that all of the work associated with many thousands of people that try to understand what is going on with our environment is wrong, that global climate change is a hoax, that there is nothing in the matter with continuing to pump all this stuff into our atmosphere and the oceans. The whole thing is completely astonishing to me.

I have a simple mind and I am a product of what I read and the people I speak to. Not only am I anxious to hold the belief, but also incapable of holding one, that counters the belief of thousands of climate scientists. It would be thinking like the earth is flat.

 

When do we need utility energy storage?

We do need storage eventually. In the United States we have less than 2% renewables on the grid, so the concept that we need storage to take that to 10 percent is completely fallacious.

 

We face many challenges when it comes to implementing large-scale renewable energy. What are these and how important is energy storage compared to them?

We get almost 50% of our electricity from coal. This is clearly unsustainable. Unfortunately there’s a ton of coal in the ground, but it’s killing us. We are gradually starting to understand this.

Last year, 13 200 Americans died directly as a result of coal pollution and there are all kinds of diseases cropping up all over the place associated with this. We are trying to mitigate this with “clean coal” among other things. We have run up against the wall when it comes to this.

Maybe we are not running out of oil, but we are certainly running out of easily accessed and inexpensive oil.

Nuclear is not an option. It’s extremely expensive and by the time you could possibly design, permit, build and deploy a nuclear reactor in the United States, which is 8-10 years, the costs would be even more ridiculous. In addition to the danger and the public outcry, the costs are going to go through the roof, while the costs of renewable energy are falling every day.

Then there’s electric transportation. We aren’t going to drive Hummer’s in 50 years. We do have a big problem to solve. We just crossed the one billion automobiles mark on the planet – a lot of combustion engines to replace, which I do believe will happen.

At the same time we need to build out the charging infrastructure. Most of the gasoline stations in the United States are prewired for 480 V three phase power. The process of getting there in terms of charging infrastructure is significant, but not insurmountable.

We are talking about the Smart Grid, and all these neat uses of information to increase the efficiency of our energy use, but we are a long way from that. Our grid is outdated and Thomas Edison would recognize most of it if he were to look at it.

The costs of technologies such as solar, wind, biomass and geothermal are coming in line. “We are heading in the right direction. Energy storage is an important component, as all of these things are.”

The problem is that it is happening so slowly, especially in the United States. My question is how much damage are we going to do in the process? Are we really willing to sit around, while A) China leads the world and B) We simply do so much damage to our ecosystems that it’s irreparable.

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The Future of Nuclear Power One Year After the Fukushima Daiichi Disaster

Exactly one year ago, March 11 in 2011, Japan was hit by a devastating earthquake with a magnitude of 9.0 on the Richter scale. Following the earthquake, a violent tsunami struck the northeast coast of Japan, where Fukushima is located.  The natural disaster claimed 20,000 lives, as well as several meltdowns at the Fukushima Daiichi nuclear power plants, which lead to release of nuclear radiation. So, what is the future of nuclear power?

A recent poll reveals that the people of Japan are starting to rethink nuclear energy: Almost 70% wants to stop or reduce the use of nuclear energy.  What are the chances of an accident like this happening again? Is harnessing nuclear energy really worth the risks?

 

No Guarantees for Safety

The Fukushima Daiichi accident is the largest nuclear disaster since Chernobyl that took place in Soviet almost three decades ago, resulting in over 4000 civilian casualties according to the World Health Organization (WHO). A Russian publication, Chernobyl: Consequences of the Catastrophe for People and the Environment, claims that the aftermath of the nuclear radiation is responsible for almost 1 million pre-mature deaths.

The extent to the nuclear accident in Japan is of course not as devastating as it was in Chernobyl. However, it does make one ponder about how safe nuclear power really is.

The nuclear reactors showed to be robust seismically; the safety systems did not work, as they should’ve when the 50 feet tsunami struck them. Although the technology behind the safety systems in the nuclear facilities has had radical improvements since Chernobyl, there are ultimately no guarantees and there never will. Nuclear processes are inherently unstable and the amounts of energy released in them, nuclear radiation and waste should not be taken lightly.

 

What About Thorium?

In the last decade, and especially after the nuclear accident in Japan, the interest in using thorium to power the fission processes in a nuclear reactors has grown tremendously.

 

Thorium possesses several noteworthy advantages:

  • The reserves of thorium have been estimated to be four times as large as those of uranium.
  • The waste generated compared to uranium is reduced by a factor of several hundreds.
  • The energy density of thorium is astonishing. The average lifetime consumption of energy is equivalent to a ball of thorium, small enough to fit in your palm.
  • Looking to the future, massive reserves of thorium can also be found on the moon. The natural element’s electro-magnetic signature makes it easy to locate on other plants from the Earth.

 

While the benefits mentioned above are very important, it is probably the fundamentally different safety system that is associated with thorium power plants that is the most impressive:

The father of conventional nuclear power plants that uses uranium as fuel, Alvin Weinberg, also lead the research of thorium powered nuclear plants, which possessed far less safety issues.

Uranium reactors use water as the basic coolant has some benefits, but also a lot of problems. The water needs to be at very high temperatures for electricity to be generated efficiently. This requires pressures that are 70-150 times the atmospheric pressure to prevent vaporization. There is no way getting around this. Accidents where there’s a pressure loss inside a reactor, resulting in rapid vaporization of water (steam), can be disastrous. If somehow the safety mechanisms designed to cool down the reactor fails, a meltdown happens and its surroundings are exposed to dangerous radioactivity.

A thorium-powered power plant does not have these problems because of a very simple reason: It is not based on water-cooling. Instead, it uses a molten salt mixture, which are remarkably chemically stable. This enables the facility to operate at much lower pressures than a uranium-powered reactor, thus eliminating the problems with water-cooled reactors mentioned above.

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It is speculated that the development of uranium power plants were at least partially motivated by the fact that the same underlying technology is the foundation of nuclear weapons.

It is comforting to see that the interest has moved away from uranium reactors and towards Weinberg’s alternative designs, as well as other fundamentally different approaches to harnessing nuclear energy.

A thorium power plant would use a mechanism called a freeze plug, a piece of frozen salt that is kept frozen by cool gas. An emergency would trigger the cool gas to stop flowing; the freeze plug would melt, ensuring that the liquid fuel inside the reactor ends up in a drain tank where it can safely be dealt with.

This is a fundamentally different approach to safety than what is used in today’s uranium-fueled power plants, where we have to provide power for safety measures to commence. In comparison, with a liquid fluoride thorium reactor, it is the absence of power that triggers appropriate safety procedures, even without human intervention.

 

The Fukushima Daiichi Aftermath

Three workers where killed at the Fukushima Daiichi nuclear power plants as a result of the earthquake and tsunami. There have been no fatalities from nuclear radiation. As a side note, it is strange to see how the media put emphasis on the event being a “nuclear” disaster.

On the other hand, the long-term problems associated with the nuclear radiation are not well known yet. Renowned physicist Michio Kaku estimates the cleanup to take somewhere between 50-100 years, and thinks the event will become the worst industrial accident in the history, topping Chernobyl at $200 billion.

The Tohoku earthquake and the following meltdowns at the Fukushima Daiichi reactors can teach us one important lesson: As long as we harness nuclear energy, we can never protect ourselves completely from nuclear accidents. That does not mean that safety can’t be improved and the risks involved can’t be reduced. Further developing thorium power plants is a step in the right direction.

Learn more about nuclear power in Nuclear Energy Pros and Cons.
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Enviromission’s Solar Updraft Tower in Arizona

The Australian company Enviromission has come a long way with their massive project for a solar updraft tower in Arizona. This structure is planned to be even taller than the current highest building in the world, Burj Khalifa (828 m), and is estimated to generate 200MW, powering about 150.000 typical U.S households.

 

How does a solar updraft tower work?

Solar updraft towers are often confused with the towers that are used in solar thermal power stations. These use large solar mirrors called heliostats to focus the sun’s rays onto the tower. Water is heated to steam and drives around turbines that generate electricity.

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There are in fact three different physical phenomena that contribute to the electricity that is generated from solar updraft towers: Kinetic energy in the wind, the green house and the chimney effect. Lets look at these in greater depth:

The sun’s radiation heats the 7 km diameter “green house” that surrounds the massive tower. The key is the difference in temperature from the base of the green house to the top of the tower.

We know that warm air rises up. This is what’s called the chimney effect. The movement of the air soon becomes wind, in other words, the potential energy that lies in the temperature difference, is converted into kinetic energy.

A gigantic suction will develop in the tower, and by strategically placing 32 large turbines at the base of the tower; some of the kinetic energy is converted to electricity, much like how wind turbines produce power (and why some call it a solar wind tower).

Enviromission initially tried to build the power plant in Australia, but due to no government incentives, moved the entire project to Arizona in the United States.

 

What are the benefits and issues with solar updraft towers?

The solar power tower has all the obvious benefits such as renewable and green, but what are the other ones? One of the major benefits of this power plant is that once it is built it costs nothing to run, other than maintenance and security.

The cost of the plant is calculated to be around $750 million and should be paid back within eleven years by selling the power that is being generated.

The power plant is due to begin delivery of power in the first quarter of 2015. We will be paying close attention to any future updates on this project.

For more details on this project, check out the interview below of Enviromission’s CEO Roger Davy:

A list of the different advantages and disadvantages of solar energy can be found in Solar Energy Pros and Cons.
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