Climate Solutions: Harnessing the Sun

In 1931, shortly before his death, Thomas Edison said to his friend Henry Ford, “I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait till oil and coal run out before we tackle that. I wish I had more years left!”

When I started putting together a solar post, I was stymied. I had an idea of what harnessing the sun should look like and I was discouraged by what I viewed as the lack of progress in the area of photovoltaics. Then I dropped my preconceived notions and began looking for the latest innovations. And I found some exciting transformations. I’ve put together a few of the new technologies I found.

Floatovoltaics are being used widely in China and Japan, but the USA has been slow to adopt the technology. But it is a promising way to harvest energy from sunlight.

“Floatovoltaics cost less to install than traditional land-based solar panels“, said Robert Spencer, a data scientist at the lab and the leader of the research. “In part because there’s no need to clear land or treat soil. And research shows that the natural cooling effect of the water below can boost the solar panels’ power production by up to 22 percent.”

Floatovoltaics offer benefits beyond more efficient power generation.

By limiting air circulation and blocking sunlight that would otherwise reach the surfaces of reservoirs, the study noted, they can dramatically limit the amount of water lost to evaporation. In addition, they can help prevent harmful algae blooms, which produce toxins that can sicken people and animals and raise drinking water treatment costs.

“The biggest benefits to installing floatovoltaics would be seen in the arid southwestern states that are dealing with scarce water resources,” Spencer said.

 

For large scale energy generation, Concentrating Solar Power installations are key in lowering the cost per kilowatt-hour, to a predicted five cents per KWH by 2030 in the US.

Concentrating Solar Power 101

CSP technologies use mirrors to reflect and concentrate sunlight onto receivers that collect solar energy and convert it to heat. Thermal energy can then be used to produce electricity via a turbine or heat engine driving a generator. Because CSP technologies collect solar energy and convert it to thermal energy that can be stored before powering a generator, they can be used either as a flexible provider of electricity, such as a natural gas “peaker” plant, or as a baseload source of electricity similar to a traditional nuclear or coal plant. CSP can also be deployed as fossil-fuel backup/hybridization that allows existing fossil fuel projects to run cleaner while operating at the same or lower cost. In the United States alone, between 11 and 21 gigawatts of CSP could be built and integrated into existing fossil fuel plants in the United States to reduce their carbon emissions – that’s enough electricity to power to between 3 million and 6 million homes.

 

 

One of the limitations on photovoltaics is solar panel efficiency. There are several innovative technologies, mostly involving layering different elements in a single cell to improve efficiency.

That efficiency might be coming. There is a worldwide race, from San Francisco to Shenzhen, to make a more efficient solar cell.

Today’s average commercial solar panel converts 17-19% of the light energy hitting it to electricity. This is up from 12% just 10 years ago. But what if we could boost this to 30%?

More efficient solar cells mean we could get much more than today’s 2.4% of global electricity supply from the sun.

Solar is already the world’s fastest growing energy technology. Ten years ago, there were only 20 gigawatts of installed solar capacity globally – one gigawatt being roughly the output of a single large power station.

By the end of last year, the world’s installed solar power had jumped to about 600 gigawatts.

Even with the disruption caused by Covid-19, we will probably add 105 gigawatts of solar capacity worldwide this year, forecasts London-based research company, IHS Markit.

 

There are some solid breakthroughs coming in photovoltaic efficiency, including perovskite solar cells, which shows great promise.

…perovskite solar cells aim to increase the efficiency and lower the cost of solar energy. Perovskite PVs indeed hold promise for high efficiencies, as well as low potential material & reduced processing costs. A big advantage perovskite PVs have over conventional solar technology is that they can react to various different wavelengths of light, which lets them convert more of the sunlight that reaches them into electricity.

Moreover, they offer flexibility, semi-transparency, tailored form factors, light-weight and more. Naturally, electronics designers and researchers are certain that such characteristics will open up many more applications for solar cells.

 

 

Incorporating photovoltaics into a variety of locations will expand the ability to generate electricity . Parking garages, commercial rooftops, sidewalks and even highway noise barriers.

Highway photovoltaic noise barriers (PVNBs) represent the combination of noise barrier systems and photovoltaic systems in order to
mitigate traffic noise while simultaneously producing renewable energy. First deployed in Switzerland in 1989, PVNBs are now found in
several countries where transportation agencies have sought ways to find multiple uses of their infrastructure. The PVNB experience
documented in literature and supplemented through a series of interviews provides evidence suggesting that noise barriers can be
designed to produce renewable energy without compromising their abilities to reduce noise, and do so safely. The business case for a
PVNB often hinges on the availability of subsidies or other incentives that promote the renewable energy market. Although the first
highway PVNB is yet to be constructed domestically, at least two State Departments of Transportation are currently working with
partners to pursue PVNB pilots in the United States. Given the substantial extent of noise barriers in the country, the potential for solar
energy production on American noise barriers is likely at least 400 Gigawatt hours annually, roughly equivalent to the annual electricity
use of 37,000 homes, and perhaps much higher.

This is a lot of information for one post, and it’s barely scratched the surface of the latest innovations. The more we improve the ways to harness the sun, the quicker we will be able to move away from coal, natural gas and oil.

 

 

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