New solar power and water purification system

Here is a link to a new solar power method that uses water and the creation of steam to generate electricity. It not only produces electricity more efficiently than PV cells but it can also purify water. The two things we need in a boat, power and water.

http://news.rice.edu/2012/11/19/rice-unveils-super-efficient-solar-energy-technology/

 

I believe it uses a dish to concentrate the solar energy. Not compatible with a moving boat.

 

When I was ten I made a solar potato cooker with my best friend. It consisted of a plastic bowl covered with aluminum foil and a stick. This was 1968 and it was the same basic system.

 

The major breakthrough here is that it doesn't require raising the temprature of the entire volume of water to 100c, the only part that is heated is the very small volume touching the nano-particles.

Assuming the cost for these things is remotely reasonable, it could be a huge breakthrough in both power generation, and desalination. For power generation it could increase efficiency by almost double compared to PV panels, since it makes use of the entire wavelength spectrum.

 

Wonder if there is a way to convert steam directly to electricity? Several stages of losses occur in going from steam mechanical to generator mechanical to electrical energy. Maybe regular PV panels would still come out ahead- in cases where the energy required is electric power? Feeding solar energy back to the grid or battery charging would be examples. Some kind of energy storage system would be needed if solar generation is used for propulsion.

Porta

 

Porta,

About 90% of the worlds electrical power is generated thru steam. If someone could figure out how to convert it directly to electricity they would be the richest man on the planet.

I don't think this is going to have any application for boats, at least not any time soon, but it could radically effect steam production, and thus power generation. Simply throw a closed loup turbine system out into the desert, and you have an instance power plant, that could run indefinitely, needs little maintenance, and has an energy efficiency significantly higher than solar.

Assuming it can deliver on the more radical promises, this coul dbe a huge step forward in renewable power generation. Think all the benefits of PV panels, but without the need for expensive and heavy silicon. Just a little distiller water, and some easy to transport nanotubes.

 

This story is probably a prank or a test to see how gullible journalists are.

To turn water into steam you need no nano technology, just a magnifying glass, a convex mirror or simply a solar collector with the control valve closed. Nice if you want to have a little bit of steam, but if you're interested in electricity you have to add a steam engine or turbine, a generator, a condensor, control circuitry and a maintenance guy who bleeds the system before a cold night can wreck the evaporator.

Needless to say that very little efficiency will be left. My estimate is 30% overall, which is better than PV, but at prohibitive investment and running costs.

 

An interesting concept. What happens to all the minerals in the water? When you turn water to steam all the minerals are left behind. How does this build up of minerals effect the tiny nanos?

 

This is what a search turned up.

Ranking engines with a pure working fluid might be the way to go, IF the nanos work in closed loop systems.... That would cut maintenance, complexity, mineral buildup and increase efficiency. But the weight and volume would be far greater than silicon PV when the whole system is considered.

http://www.mpoweruk.com/steam_turbines.htm

Porta

 

i have a family member working as a project manager which is building the first power station in Australia that is based on solar steam technology... The solar collectors are special in that they have a special 3D, non-imaging optical surface to maximize energy collection from the sun as opposed to a traditional compact linear fresnel reflectors... it heats the water directly into steam...

I beleive the system is close looped, using RO water for the steam, so theres no chance of mineral build up...

The power station is backed up by natural gas fired operation in a hybrid type system...

The tech has already been proven on a small scale system, now theyve started building the larger version for power generation, wont be online for a few more years tho...

 

Yes, on a large scale such projects are feasible and can even make a decent profit.
The Sener engineering group in Spain built their first power plant in Andalucia around 1980, it probably is still operating.

 

Yes, the compact linear fresnel reflectors are in use in a few places and have been for many years, this new project here is based upon the same principal but with the new improved reflectors with the 3D surface in an effort to improve efficiency...

 

I doubt it will get all the way to 30% and t here is also the q

 

30%?

I have a 2m2 collector in Greece and at most, on a cloudless, sunny summer day, I get about 40 gals rising from 80F to 150F. Roughly about 20k btu, or about 5.5kw.

A 2m2 sloar panel on the same roof will produce about 2kw.

Ball park, they sound reasonable BUT then we have to convert that solar powered into electricity and then we are going to have hefty losses.

A few years back, there was a Sterling engine project and the best they hoped to achieve was 25% efficiency. Best current solar panels are running into 20% and about 17% net after converters/wiring.

 

Last year I installed a new collector, made by a company in Austria. They use two copper sheets, machine welded every 2 inches over the whole length. Then they pressurize it to create a very narrow gap, so it contains less than half a gallon of water.

It is so bloody efficient I had to install a radiator on the outside wall of the house to get rid of the heat in summer after the solar boiler has reached the maximum temperature!