Friday, 26 April 2013

Tipping point coming in photovoltaics?

A recent article in Engadget provides an exceptionally balanced and informative description of emerging technologies in the area of solar photovoltaic energy generation.  The amateur futurist in me is very tempted to suggest that we are seeing the first concrete evidence of a likely change of direction for renewables.

In the last few years, we have pinned a lot of hope on the evolution of PV to make possible building integration and distributed power generation.  Each is very attractive, the latter because it helps make the system potentially safe from single points of failure.

But there has always been a tension between that approach, and centralised systems feeding ever larger grids.  Wind power has gravitated towards 'bigger is better' because it is - bigger turbines are more efficient, and big wind farms are best located where the wind resource is the best.  With photovoltaics, big concentrator technologies have not had the same obvious compelling advantages.  But now it is emerging that they do have.

A team of IBM researchers in Switzerland is working on an implementation of a High Concentration Photovoltaic Thermal system, that will start with significantly greater electrical conversion efficiencies than BIPV technology.  But with well integrated thermal technology, it actually should be able to collect 80% of incoming sunlight and convert it to useful energy, while employing robust and low tech materials for its construction.

The actual solid state chips that do the electrical conversion remain high tech, as do the fundamentals of the extraordinarily effective cooling system, which is required to accommodate the heat generated by a concentration of 2000 to 5000 times the intensity of the incoming solar radiation. But the project team have thought through the rest of the system to replace expensive steel and glass with low cost concrete for the support structures, and simple pressurized metalized foils for the optics.

Emerging trends to district heating and even district cooling prompt the other synergies in the proposed technology.  The very high temperature fluid cooling is coupled with desalination or district heating potential, and with district cooling using absorption chillers.  Given thermal storage is already a well studied market, the promise of a centralised, but scalable solar/thermal generation is becoming very attractive.

IBM expects that the system would be approximately one third the cost third of current comparable technologies, but hasn't promised when the technology will emerge from its research phase to full prototyping.

Read more:


Anonymous said...

Solar technology has been talk of the renewable energy community. It has been seen to have the most potential energy production to the masses. As energy from the sun is "free", in the sense that there is no need to mine for it and it readily available whenever the sun is up even if is a cloudy day (to some degrees). It is the unavoidable truth that there must be new renewable technologies for energy production that need to be researched and developed for the future.
However the current technologies are too expensive and slow to produce at a large scale for continually growing populations of major cities around the world.
Thus with new developments such as the one with IBM, it will help make solar energy a lot more viable and more attractive to large energy companies who are in the face of the rising costs of fossil fuels such as coal and gas. Thus it can be said that, as the clean energy council puts it, "solar energy is an insurance policy against rising costs of fossil fuels like coal and gas". However at the moment in countries such as Australia where Coal is still relatively cheap, abundant and produces the majority of energy for Australia. Thus it would be a extremely costly to replace current energy infrastructure with new renewable energy producing techniques. Systems such as the one by IBM which claims that it would approximately one third the cost of current comparable technologies it would definitely be of much interest to many investors.
Despite this technology being constructed out of robust and low tech materials for construction. How much environmental impact will these have on the environment? Will the maintenance and production effects on the environment be outweighed by the benefits of these new solar technologies? As it is well known that Solar technologies are heavily reliant on silicon and to some degree rare earth metals. Both of which cause drastic environmental impacts when mined for and processed. Although it can be argued that coal mining also causes detrimental environmental impacts.
It is extremely obvious, at this current day and age, that there is a need for new technologies such as this to be developed, but we must weigh the environmental impacts of developing these technology against the current situations, as the current solar panel technologies are far from a perfect solution.

Steve King said...

One of the points made in favour of the type of concentrator technology described in the post (or at least strongly implied in the referenced article) is that triple-junction photovoltaic cells do not use rare earths to the same extent as the current PV technologies. Unfortunately, my technical expertise doesn't extend to that detail.

But the comments after the Engadget article are starting to mount up, and cover a lot of ground. Worth reading.

James Hargrave said...

I find the advancements we are making in photovoltaics and solar collectors very interesting, it appears new technologies are allowing us to create smaller yet more efficient modes of collection. I feel it is important to point out that we are yet to establish a highly efficient way of transporting this new green energy or any energy for that matter to our cities without incurring significant loss along the way.

It is recorded that an average of 7% of the electricity pumped into our grid is lost in transmission which is supposedly quite good. I see it as the equivalent of trying to put out a large fire using a bucket full of holes. I feel there are a number of issues we need to address as soon as possible to take full advantage of the future in green energy.

We have all started to make the change to more efficient lights, TV’s, computers, air conditioners, etc. With the prospect of an exponential increase in population and the proportional increase of energy demand, we are going to need to produce a lot more energy. With the energy consumption culture changing on the front line and the radical green changes in the supply of energy the main changes are yet to be seen are from the man in the middle (the grid).

With the potential future demands for electricity we can only assume that a loss of 7% in transmission is not good considering that most of that energy today comes from coal powered energy plants. 5416.04 tons of coal is burnt by a single energy plant a day to generate 500Mw, that would equate to 380 tons of coal being burnt every day just to get it to our light switch. This says to me that we are in need of a highly efficient grid, or a new approach towards the transmission of energy.

There is a project under way in New York at the moment where they are installing liquid nitrogen chilled cables which turns them into superconductors effectively removing significant energy loss in transmission while allowing them to carry ten times more electricity. It is a very costly exercise, and implementing this on a mass scale just doesn't seem feasible.

In the last few years significant advancements have been made in the area of personal collection and storage of natural energy. In a TED talk I recently watched Justin Hall the CEO of Nanoholdings spoke of three new technologies his company has been developing. They have effectively created thin and clear plastic like material from carbon nanotubes. Carbon nanotubes can be one of two things, a super conductor, or super insulator it just depends on which way they are folded. This plastic material was made as a super conductor which is 1000 times more conductive than copper wire. It has the ability to collect infra-red radiation (day and night) and when combined with a special micro processor attached to it’s surface it is capable of converting incident radiation into electricity. Due to its clear state such a material could be easily installed on any window/s in any house. The third technology is a device called “e-box”, this device is infinitely more efficient than any other method of energy storage. It uses nano materials to collect electrons and “park” them on the outside of a nano material where they can be used at any moment they are required. With the combination of all three of these technologies it opens immense possibilities to the future of our energy collection, transmission, and storage.

Wind farms, solar panels, hydro facilities etc. may be a thing of the past as competing with such an efficient and personal method of energy collection and storage may very well be the way of the future.


Chilled Pipes:

TED Talk:!