Solar Record

A company called First Solar has just raised the bar for every other photovoltaic cell manufacturer by setting a record for PV efficiency. First solar, among other things, makes cadmium-telluride (CdTe) solar cells and increased their efficiency to 17.3-percent.

According to First Solar, “…it set a new world record for cadmium-telluride (CdTe) photovoltaic (PV) solar cell efficiency, reaching 17.3 percent with a test cell constructed using commercial-scale manufacturing equipment and materials. The test cell’s performance, confirmed by the U.S. Department of Energy’s National Renewable Energy Lab (NREL), far surpassed the previous record of 16.7 percent set in 2001 … The average efficiency of First Solar modules produced in the first quarter of 2011 was 11.7 percent, up from 11.1 percent a year earlier, and the company has recorded full-module efficiencies over 13.5 percent, with a 13.4 percent module confirmed by NREL. First Solar’s module efficiency roadmap sets a goal for production-module efficiencies of 13.5-14.5 percent by the end of 2014.”

Now, this may not sound like a big deal on first glance, but from early 2011 to mid- 2011, First Solar has increased the efficiency of its solar cells from 11.7-percent to 17.3-percent which is a huge leap for an industry that measures itself by one-tenth of a percent increments.

Look, if you’ve read this far then this means I have you a little excited with this news. But, there is even bigger news in breakthrough solar technology. Just two days ago a startup in Santa Clara, California called Alta Devices scored a huge victory by upping its thin-film gallium-arsenide cell to 28.3-percent efficiency.

According to ieee Spectrum, “The key to achieving the record was photon recycling. When the photons in sunlight are absorbed in a photovoltaic material, they split into an electron and a hole. The electrons that pass out of the cell can be used as electricity, but many of them are lost in the semiconductor when they recombine with a hole to produce either waste heat or a new photon. By carefully growing a high-quality single crystal of gallium arsenide, the company managed to ensure that more than 99 percent of the recombinations would result in new photons.”

Both of these breakthroughs are exciting developments in the field of solar energy. We are at a tipping point my friend where efficiency goes up and cost comes down to a price that is starting to make solar energy competitive with fossil fuels.

Many of these breakthroughs have to do with lowering the costs of producing the venerated photovoltaic cell. Photovoltaic, or PV, cells are what grab the sun’s rays and convert them into usable energy. Traditionally, these have been expensive to mass produce even though, once in place, they produce one hundred percent clean and renewable energy, leave no carbon footprint, and last over a quarter of a century.

One breakthrough discovered by physicists at the University of Illinois is that a covering of silicon-based nanoparticles on a PV cell can drastically increase its energy output. Conventional PV cells have been limited for the most part to converting light into energy and discarding the potential in the heat energy produced by the ultraviolet range of the sun’s energy spectrum. The integration of this tiny layer of silicon nanoparticles allows some of that ultraviolet energy to be converted into electrical energy instead of being lost as extra heat and therefore improves the cell’s performance by nearly sixty percent in the ultraviolet range. And, best of all, coating a PV cell with this thin layer costs next to nothing.

Another improvement comes in the form of cadmium telluride. Traditional PV cells must be coated thickly with crystalline silicon, which is quite expensive. Cadmium telluride, a similar crystalline compound, costs about half the price of silicon, can be coated thinly on glass to extract energy from the sun’s rays, and is a great substitute for silicon. Although this compound was suggested for use in solar panels as far back as the 1950s, it was only recently that its use became feasible due to the discovery of a simpler and cheaper manufacturing process. A company named AVA Solar was recently given a three million dollar grant from the US government to research further into the possibilities of cadmium telluride and, barring any serious business litigation from their opponents, should begin to make some serious progress in introducing this compound into mainstream solar energy cell fabrication.

Other breakthroughs have been in the fields of reducing the thickness of the PV cell. A thinner PV cell means one that uses fewer raw materials, costs less, and is easier to manufacture. Thin-layer PV cells are being intensively researched in the solar energy community and have been steadily improving in their efficiency and potential. Another idea has been to use a carbon based polymer to create an organic PV cell that traps a comparable amount of light energy at a fraction of the cost. Both of these potential alternatives to mainstream solar energy technology still need much research and investment before they may be used commercially but steady progress is being made.

According to the LANL, “The new material is a semiconducting polymer spiked with ‘fullerenes’ – soccer-ball-shaped, cage-like molecules composed of 60 carbon atoms. When applied to a surface under carefully controlled conditions, the material self-assembles in a repeating pattern of micron-sized hexagonal-shaped cells resembling a honeycomb. Researchers created reproducible films of up to several square millimeters in area.”

Now, this could have some impact on the residential solar panel market as homeowners would be able to put these solar panels integrated into their windows either reducing the size of the solar panels on the rooftop or eliminating them altogether depending upon the type of home.

But, what may have even a larger impact is within large cities that have a lot of buildings including skyscrapers with literally tons of glass windows. Industrial and commercial businesses use far more energy in the U. S. than do residences.

If large facilities were equipped with either window solar panels or traditional solar panels or both, this would mean a dramatic savings in energy consumption from the grid. Now, fast forward 10 years and imagine new homes and businesses being built with solar windows as a standard part of construction. The grid as we’ve come to know it will never be the same.

When finished in 2013, the concentrating solar power project will be able to supply green energy to 90,000 homes. The Mojave Solar plant is being built upon 1,765 acres of an abandoned alfalfa farm just west of Barstow, CA and will use less water than the farm did to operate.

According to Abengoa Solar, “The plant uses parabolic mirrors that are arranged in long troughs and track the sun’s movement continually during the day, concentrating the solar radiation onto a heat-absorbing pipe at the focal point of the mirrors. A heat transfer fluid circulating inside the pipe reaches temperatures of more than 700 degrees Fahrenheit. This heat is then used to generate steam that drives a conventional steam turbine.”

If you’ve ever driven through Barstow, you’ll soon realize why some call it the “armpit of California” and what better place to put a large solar facility than a place where summer temperatures typically exceed 100 degrees F.

The new Abengoa Solar plant excites me for several reasons. First, since it’s only 86 miles from my home it will be easy to take an occasional trip there to check it out, take pictures and see the progress of the facility.

Second, I also live in San Bernardino County and as a resident, I know that last month the unemployment rate was 14.2-percent, which is quite a bit above the national average. While not solving the unemployment problem in the county the Mojave Solar project will provide 1200-plus good green jobs in the area. And, third, maybe I’ll be one of the lucky recipients of this green solar power in the future.

The Mojave Solar project is just one of many in the works right now that will offer good green jobs to many and bluer skies for all.

This consumption of water especially in the southwest states of Arizona, Nevada, California and New Mexico may add a burden on these states to come up with what is needed. But, there are a couple of complications. First, environmentalists may not accept the diversion of water resources that can damage native fish and other wildlife populations.

Second, in states such as California that is coming close to rationing water in some parts of the state a large solar facility will add an extra burden. And, a third complication is that in places such as Nevada the water rights and property rights are separate.

So, this third complication may mean that farmers won’t want to give up their water rights to have a large solar farm constructed in their backyards. On the flip side, there are investors who have speculated in buying water rights on properties for the sole purpose on making money in selling these rights to a presumed nuclear or solar facility in the future.

The large solar companies are trying to keep these battles out of the courts by negotiating with the states, environmentalists and smaller water rights owners. But, with this much complexity and competing interests there is a high likelihood that a few judges will be brought into the mix for good measure.

Ersol Solar Energy AG (Ersol) donated 98 panels of 130 watts each. Without the solar panels the only means of electricity for the health clinic (which is fairly remote and about 60 miles from the nation’s capital) is a noisy, polluting diesel generator.

The VHW clinic mostly helps fight HIV/AIDS in this third world nation. Besides installing solar energy to remote African locations, SELF also delivers wireless communications, water pumping and purification and drip irrigation systems.

SELF is a selfless organization that not only takes care of the needs of the poor nations but does so in a green and global-friendly manner.

At this point consumers may see the value of installing solar panels and cost averaging them over a 25 year period in order to realize the savings. Or better yet, some solar panel installation companies will do this for you.

They will install the solar panels for free and then charge homeowners a flat monthly rate over the next 25 years for the electricity produced and in most cases the cost will be less than that charged by the large utility companies.

The solar grid parity situation will also create jobs for entrepreneurs who will be able to compete head on with the utility companies. Given a choice, many consumers will opt for even monthly payments from solar energy rather than paying the winter / summer rates and changing fees from the utility companies.

Also, homes in sunny areas will be less affected by blackouts and brownouts in summer months during peak demand. In fact, in some areas, homeowners will be able to sell solar electricity back to the utility companies and roll back their meters. And this would be a sweet situation to be in, now wouldn’t it?

The sunlight is then converted into chemical energy. The Dutch scientists are using concentric nanotubes to replicate the structure of plants at the microscopic level complete with high levels of chlorophyll inside the nanotubes.

The varied structures of the chlorosomes and chlorophyll mean that light can be absorbed in a wide range of wavelengths. In addition, the chlorophyll can even be activated in very low light conditions.

The key findings include a helical structure and dense packing of chlorophyll in the plants. This means more energy can be absorbed, yet the plant is protected from too much sunlight. The Dutch researchers hope to be able to create solar cells based upon these plant cell findings.

The efficiency of the solar cells is increased by as much as two percent, which is significant for this renewable technology. Because of the etching, the reflection is reduced to less than five percent overall. As much as 10-percent of the light hitting traditional solar cells can be reflected due to dirt and dust build up on the surface.

The solar etching technology allows rain and dew to wipe the photovoltaic surface clean. Even in desert areas there is enough dew at night to remove dust from the cells. The ability of dust and dirt to bead up with moisture and roll off is called superhydrophobic.

Self-cleaning solar arrays will also help in the longevity of the photovoltaic panels, which will reduce overall costs. With the new U. S. Stimulus Package favoring solar energy, many will keep a keen eye on this technology going forward.

In fact, these glass and composite solar roadway panels are so tough that an 18-wheeler can flip over on them without wiping them out. They also have to be durable and cost-efficient compared to asphalt, not to mention they will produce electricity for homes and businesses nearby.

The solar roadways have to beat the current low ball cost of $16 per square foot for asphalt with a life expectancy of over 7 years. Solar roadways could be used in residential neighborhoods, near schools and businesses to supply power. Right now the highways and byways of the U. S. collect heat and tire wear and give very little back.

The solar roadways will change this by giving back electricity that is renewable, decentralized and cost efficient when economies of scale are taken into consideration. Under the current U. S. stimulus package, President Obama wants to hire construction companies to repair roads and bridges.

He also wants to put people to work building solar panels and other photovoltaic projects. Solar Roadways combine these two goals into one package by employing construction workers in the photovoltaic industry and vice versa.

Solar Roadways has just been named a finalist in TechInsight’s EE Times fifth Annual Creativity in Electronics (ACE) Awards. So, the next time you’re driving down the road, think of how solar-powered streets could one day be supplying electricity to the homes and businesses in your city and neighborhood. Now, blink and fast forward a couple of years, and this may just be a reality.