solar

Solar Power with Salt

- Adam Clare

Thermal solar power plants uses energy from the sun to heat up water and then run the resulting steam to power turbines. Simple enough, but now Siemens is looking to make that whole process more efficient by using salt.

Solar thermal power plants that produce hotter steam can capture more solar energy. That’s why Siemens is exploring an upgrade for solar thermal technology to push its temperature limit 160 °C higher than current designs. The idea is to expand the use of molten salts, which many plants already use to store extra heat. If the idea proves viable, it will boost the plants’ steam temperature up to 540 °C—the maximum temperature that steam turbines can take.

Siemens’s new solar thermal plant design, like all large solar thermal power plants now operating, captures solar heat via trough-shaped rows of parabolic mirrors that focus sunlight on steel collector tubes. The design’s Achilles’ heel is the synthetic oil that flows through the tubes and conveys captured heat to the plants’ centralized generators: the synthetic oil breaks down above 390 °C, capping the plants’ design temperature.

Startups such as BrightSource, eSolar, and SolarReserve propose to evade synthetic oil’s temperature cap by building so-called power tower plants, which use fields of mirrors to focus sunlight on a central tower. But Siemens hopes to upgrade the trough design, swapping in heat-stable molten salt to collect heat from the troughs. The resulting design should not only be more efficient than today’s existing trough-based plants, but also cheaper to build. “A logical next step is to just replace the oil with salt,” says Peter Mürau, Siemens’s molten salt technology program manager.

Read the rest of the article.

Solar Power for Gas Production

- Adam Clare

Here’s a novel idea to conserve energy, use the sun to separate chemicals which can then be used as fuel thereby consuming less energy to create fuel.

Researchers have developed a novel thermochemical reactor that uses sunlight to convert carbon dioxide and water into hydrocarbon-fuel precursors at a relatively high efficiency.
…
The new thermochemical reactor is believed to be more efficient than previously developed ones, whose efficiencies could not be comparably measured. And it is amenable to continuous operation, suggesting that an industrial-scale version of the process could be developed for solar towers.

Read more here

Solar Snow Removal

- Adam Clare 1 Comment

It should come to no surprise that the sun melts snow and ice. Indeed, one of the reasons we have such severe climate change is because the energy from the sun isn’t being reflected off of snow (the albedo effect).

Some enterprising researchers have proposed that we capture the energy the sun is tossing at us by using roads to store energy that can be later used to melt snow or provide energy. Imagine all the roads in North America as an energy source!

“We have mile after mile of asphalt pavement around the country, and in the summer it absorbs a great deal of heat, warming the roads up to 140 degrees or more,” said K. Wayne Lee, URI professor of civil and environmental engineering and the leader of the joint project. “If we can harvest that heat, we can use it for our daily use, save on fossil fuels, and reduce global warming.”
The URI team has identified four potential approaches, from simple to complex, and they are pursuing research projects designed to make each of them a reality.
One of the simplest ideas is to wrap flexible photovoltaic cells around the top of Jersey barriers dividing highways to provide electricity to power streetlights and illuminate road signs. The photovoltaic cells could also be embedded in the roadway between the Jersey barrier and the adjacent rumble strip.
“This is a project that could be implemented today because the technology already exists,” said Lee. “Since the new generation of solar cells are so flexible, they can be installed so that regardless of the angle of the sun, it will be shining on the cells and generating electricity. A pilot program is progressing for the lamps outside Bliss Hall on campus.”
Another practical approach to harvesting solar energy from pavement is to embed water filled pipes beneath the asphalt and allow the sun to warm the water. The heated water could then be piped beneath bridge decks to melt accumulated ice on the surface and reduce the need for road salt. The water could also be piped to nearby buildings to satisfy heating or hot water needs, similar to geothermal heat pumps. It could even be converted to steam to turn a turbine in a small, traditional power plant.

Read the rest at Physorg

Solar Energy to Power Trains

- Adam Clare

Trains are a great transit solution and are efficient at moving people and goods. Trains are really a green way to travel.

In Belgium, they are taking this green form of travelling and making it even better by powering the trains using solar power.

More than 16,000 solar panels will be installed on the roof of the high-speed rail tunnel stretching just over 2 miles long. The tunnel is primarily used by the high-speed train connecting Amsterdam and Paris via Brussels.

The roof’s total surface area is 50,000 m2, roughly equivalent to 8 football fields. The installation should generate an estimated 3.3 MWh of electricity per year.

The installation commenced this summer on the tunnel’s northern side. Project completion is scheduled for December 2010. The total investment budget is $20.1 million.

Infrabel, the Belgian railway infrastructure manager, will use the green energy in the Antwerp North-South junction (including Antwerp Central Station) and to power both conventional and high-speed trains running on the Amsterdam-Brussels-Paris line. With this project Infrabel has re-emphasized its belief in renewable energy as a viable alternative, and complement, to conventional energy sources.

Read the full press release.

Even Cheaper Solar Cells

- Adam Clare

We recently reached the point that solar power is cheaper than nuclear power and now some researchers at the University of Toronto have found a way to make solar cells even cheaper by using nickel instead of gold.

One of the major drawbacks of most renewable energy sources is high cost. In order to see a huge rise in the use of renewable energy sources, prices must come down. In the world of solar there have recently been some major breakthroughs in cost advantages and efficiency increases. Scientists at the University of Toronto in Canada have come up with a way to reduce colloidal quantum dot solar cell prices by up to 80%, by swapping out costly conductive gold for cheap nickel.

Read more: Super Cheap Solar Cells Just Got Cheaper, Switch Gold For Nickel

Scroll To Top