New type photovoltaic film solar panels: cost-benefit analysis

The prices of photovoltaic panels in the last 10 years have decreased due to the exponential increase in demand did reduce the cost of production on a large scale. This growth, however, a bit contrived because of the incentives, especially in our country, generous and in some cases distortion of market logic.

With the introduction of new incentive mechanisms for renewables the first question that arises is whether the industry will see a drop in demand for 2011. According to the latest data, the installed capacity in industrial plants will be sufficient and will exceed the current demand: The estimated by Credit Suisse secure the industrial demand for solar cells in 2011 to around 14,000 MW (peak), compared with a production capacity of 25,000 MW ( peak)

It remains an open question of energy efficiency family: the technology for energy absorption is changing with remarkable frequency and the yield of PV could increase, improving the convenience at the household level.

To date, both the cost of photovoltaic modules and structures accounts for about 50-70% variable depending on the installed capacity and is the longest-running investment with a term that can touch 50 years. The economic difficulties remain also in other components such as inverters, currently difficult to obtain due also to the fact that the photovoltaic systems are intended to change very quickly.

Typical installations of the first generation (monocrystalline or polycrystalline) have now arrived at a mature stage of technological development. The efficiency no longer increases significantly and the energy cost is about 25 cents / KWh € (without incentives). The production with fossil fuels is estimated, however, between 6 and 8 cents / € but it would be wrong to compare the two figures.

In fact, careful reasoning would lead to the realization that you are comparing a price "home" with respect to the production of power plants and the consequent rise in the early stages of transportation and sale. The 25 cents today represent the "almost" grid-parity for the end user: the photovoltaic plants produce energy at a cost of 25 € cent, which corresponds to what is paid the same consumption in the bill.

The promise of better performance comes from the second generation of renewable energy plants, the thin-film photovoltaics. The technology is changing rapidly, and enables a better performance than the older panels: even grid parity in absolute terms begins to approach 13-15 cents € in the best hypothesis. To arrive at a truly equal must, in addition to further reduction of costs, even an increase of efficiency to knock down the impact of the BOS.

According to the latest research from the Politecnico di Milano the thin-film technology, since 2008 where it was used in 16% of cases, arrive at a spread of 34% by the end of 2012.

The standard (to build thin-film silicon cells, single junction, triple-junction, tandem amorphous and microcrystalline) has not yet been fixed but the costs of amorphous silicon, cadmium telluride, cadmium sulfide, gallium arsenide, indium diselenide copper and copper indium gallium diselenide give precedence to the latter at the moment. There are still difficulties, for some materials, related to the maintenance of efficiency of the time, the toxicity (cadmium for example), or the cost of monocrystalline material (as for GaAs).

What will be then the thin-film technology most used? The price will decide the winner as there are today large-scale production problems with any of the materials examined. Currently, the amorphous silicon has an efficiency among the lowest (between 6.5% and 7%): American scientists claim that prevail at least in the initial stage and has no toxic effects such as cadmium telluride, which has achieved a cost production among the lowest but is toxic if it is entering the environment.

There are still some defects in current standardization for copper indium diselenide and copper indium gallium diselenide, which currently already reaches an efficiency of 9% even if it turns out, as shown above, the most promising.

Research in recent months has made progress by leaps and bounds: in the laboratory it has come to achieve an energy efficiency of over 20% while in the U.S. as companies like MiaSolé are starting the sale of panels polymeric material CIGS (copper, indium, gallium and selenium) that reach the same performance of crystalline silicon, which is almost 16%. The costs are even higher but the research predictions (fixed at 13% for 2011) are hoping for a rapid reduction in marketing prices, thanks to energy savings in the manufacturing process (450 degrees against the previous 550 needed).

The CIGS has a conversion efficiency of stable which allows consistent performance for many years: also the use of aluminum as a substructure ensures a high level of conductivity and very low cost, without having to separate the deposit process on the panels of a lower layer that functions as an electrode. Thereby reducing the 99% of the silicon used compared to traditional panels can be a cost savings, which benefit mainly the plants on a large scale.

The costs compared

To date, the fall in prices on the door multicrystalline an estimate for 2015 around $ 0.93 / W (compared to $ 1.30 / W in 2010). The cost reduction will also occur through a greater efficiency of the structures that will go from a yield of 14.0% in 2009 to 16.1% in 2015. Improvements for the silicon film that will go from the current efficiency of 9.0% to more than 11.0% bringing the costs 2010 by $ 1.25 / W in at $ 0.80 / W in 2015.

The CdTe technology remains the most economical despite being the least efficient: there is a descent from $ 0.75 / W in 2010 to $ 0.54 / W in 2015.

The real novelty in terms of costs will be for CIGS technologies according to the latest data will fall from $ 1.69 / W to $ 0.76 / W in 2015 and will be guaranteed an efficiency of 14.2: all while maintaining margins gross for developers of over 30%.

How will be 2011 for the price of solar panels?

The period that lies ahead, despite the cuts, will not be so simple: it is made massive use of photovoltaic cells, transformed into abuse in recent years.

The change of direction of the incentives will lead to a decrease of about 6% per annum of the installations. Will the Chinese to get the prices down: in spite of overseas technologies are not yet available to everyone you can reach much higher energy efficiency for a measly dollar per watt. Grid parity is getting closer.

12/01/2011

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Translated via software

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Source:

Italian version of ReteIngegneri.it