PV roadmap: Near-maximum efficiency could be achieved in 10 years

DUBLIN, IRELAND: Research and Markets has announced the addition of the "Photovoltaic Technology Roadmap" report to its offering.

Making photovoltaics a low-cost source of clean and renewable energy is the main goal for most of developed countries. Many of them have agreed on a 20 percent renewable energy target by 2020, and some already started to implement aggressive feed-in-tariffs to finance this objective. But, the question is how do we get there from what has been achieved so far?

What would happen if governments partially stop financing the PV industry through incentive program cuts as in Germany for instance? Can todays technologies be competitive without the incentives or do we need technical evolutions, or even technical breakthroughs to get there?

There is no doubt that the government incentive programs helped industrials to achieve, step by step, drastic cost reduction and performance improvements in a very short period of time but without real revolutions.

The PV industry has also seen the emergence of large-scale production facilities, international R&D centres, and innovative equipment makers thus resulting in the impressive cost reduction we know. But if large production facilities can play the scale effect card to lower the cost of raw material and increase their yield, many other levers exist in order to reduce the production cost.

This PV Technology roadmap report describes all the different aspects linked to production cost reduction: from cell structure innovations to modification of manufacturing processes. It in fact describes all the existing technologies: From those developed by the University of New South Wales (UNSW), to the metal wrap through (MWT) concept developed by the ECN and industrialized with Solland, to the new emitter wrap through (EWT) technology being developed by Bosh Solar.

Conventional crystalline silicon cells could bump up against their theoretical maximum efficiency of 29 percent as soon as 2020. Sanyo Electric Co. Ltd, for instance, demonstrated -23 percent efficiency with a 10cm R&D unit of its heterojunction with intrinsic thin layer (HIT) cells last year.

It follows that thinner surface contacts, better transparent conductors, and lower defect density can improve performance by several more percentage points, to likely get commercial efficiency up to about as close as practical to the theoretical limit within about 10 years.