Funded by Research Councils UK (RCUK) and the Government of India (GOI) Department of Science and Technology (DST), each organisation has committed up to £5m over a three-year period.

(Right) Dr A Mukhopadhyay (Department of Science and Technology, India) and Dr Jason Green (Engineering and Physical Sciences Research Council, UK) sign the record of decisions at the end of the joint panel meeting.

Solar energy has been identified by both the UK and India as an area of significance in providing solutions to the problem of meeting future energy needs.  The ‘Advancing the efficiency and production potential of excitonic solar cells’  project will focus on the development of materials, device structures, materials processing and photovoltaic-panel engineering of *excitonic solar cells.

It will build on existing research in both the UK and India to develop cheaper and scalable solar cell manufacture. The project has been awarded £2.5m  by RCUK, matched by DST.

A second project, ‘Stability and performance of photovoltaics’, aims to remove known bottlenecks in materials supply and develop novel device designs that are significantly cheaper and more efficient than current solar cells. RCUK grant value is £2.4m, which is equalled by DST.

Dr Neil Bateman, Engineering and Physical Sciences Research Council (EPSRC) Energy Portfolio manager said: “These projects represent a new and exciting collaboration between some of the leading photovoltaics researchers in the UK and India. The research is targeted at pushing the science of solar energy towards cheaper, more reliable and sustainable electricity production in a wide variety of settings.”

The projects form part of the RCUK Energy Programme led by EPSRC and the Solar Energy Research Initiative of the DST (GOI), and are in line with an ongoing goal of strengthening collaboration between UK and Indian research institutions.

(18) For Advancing the Efficiency and Production Potential of Excitonic Solar Cells (APEX) the lead institutions are the National Physical Laboratory (India) and Loughborough University (UK). Indian research partners comprise: National Chemical Laboratory, Jawaharlal Nehru Centre for Advanced Scientific Research, Indian Institute of Technology Delhi, Indian Institute of Chemical Technology, Indian Institute of Technology Kanpur.

UK research partners are: University of Edinburgh, University of Cambridge
University of Oxford, Imperial College London.

Other partners are from India: Moser-Baer, Bharat Heavy Electrical, The Solar Energy Centre. From the UK, Pilkington Group, DuPont Teijin Films, G-24i, The Solar Press.

For researchon Stability and Performance of Photovoltaics (STAPP)
Lead institutions are IIT Bombay (India) and Loughborough University (UK).
Indian research partners: IIT Bombay, Solar Energy Centre, IIT Kharagpur,
IIT Kanpur.
UK research partners: University of Strathclyde, Northumbria University
Loughborough University, Imperial College London.

Other partners are: India: Reliance Industries, HVV Solar Technologies,
West Bengal Green Energy Development Corporation, Solar Semiconductors, Tata BP, Solar India, Shurjo Energy, BHEL and Lancosolar
UK, IPSoL Test,Solar Century Global Community Trust, New and Renewable Energy Centre, Leapfrog, IT Power, PerkinElmer and the European Commission Directorate-General Joint Research Centre, Italy.

Abundant materials and coating approach
IBM  research recently published on High Efficiency solar cell with earth abundant liquid-processed absorber. Tossing out cadmium (toxicity) indium and tellurium (rare) the new cell uses copper, zinc, tin, selenium and sulphur.

Advantage of the new cell is that it can be  manufactured using a simple, non-vacuum process based on what the researchers call a "slurry-based coating method."

That allows the PV layer to be applied by printing, spraying, spin-coating, or other liquid-based techniques.

The efficiency of the new experimental cell is currently at 9.6%,  not far off that of most commerically available solar cells today. IBM's research, however, is still at an early stage, and"earth-abundant" cells may very well match or surpass current - and relatively expensive - cells at a lower cost and with higher availability.

Polysilicon solar pushes 19.3% efficiency for Mitsubishi
Mitsubishi Electric Corp achieved a cell conversion efficiency of 19.3% with a polysilicon solar cell measuring 15 x 15cm. The conversion efficiency is higher than the 19.1% efficiency in September 2009. The efficiency was measured at Japan's National Institute of Advanced Industrial Science and Technology (AIST).

The efficiency gain came from adding a cleaning process before forming electrodes on the front and back surfaces of a silicon wafer.

As a result, the connection resistance between the silicon wafer and the electrodes reduced by 4%, improving conversion. The company uses the "honeycomb texture" structure, which reduces the light reflection on the front surface of a cell, and the "BSR (buck surface reflector)," which increases the light reflection on the back surface of a cell. The conversion efficiency of 19.3% was achieved with a polysilicon solar cell with a thickness of 200μm.

Mitsubishi Electric applied a similar technology to 100μm-thick cell to reduce its costs achieving an18.1% efficiency,  0.7% higher than in August 2008. This cell also has the world's highest conversion efficiency as a thin cell measuring 15 x 15cm, the company said.

Batteries should be included
Mitsubishi Electric Corp prototyped a storage battery device (left) by combining a lithium-ion (Li-ion) capacitor and a Li-ion secondary battery in a cell.

The device has high-speed charge-discharge characteristics of a capacitor and long charge-discharge time of a Li-ion battery. It is expected to be used for regenerating power from a large-size motor and leveling  output of a photovoltaic system.

Though Mitsubishi Electric plans to commercialise the device, it does not have a specific schedule for it. The company has prototyped two types of the device. One is for  verification of principles, cell size of 3 x 3cm, the other is for the verification of practicality, cell size of about 9 x 6cm.

The cycle life of the 3 x 3cm is at about 2,000 cycles or 20% decay rate
The 9 x 6cm "flat winding type" and has an output of 14Wh. Output density and energy density are approximately 3kW/kg and 60Wh/kg, respectively. The average voltage, lower limit voltage and upper limit voltage are 3.2V, 2V and 4V.

Both have a negative electrode shared by the capacitor and the battery. A positive electrode and separator are prepared for both capacitor and the battery. The shared negative electrode of the 3 x 3cm type is sandwiched between the "first positive electrode" of the capacitor part and the "second positive electrode" of the battery part. With the 9 x 6cm,first and second positive electrodes are formed on the front and back of a collector foil, separator and the shared negative electrode being flat wrapped. Key to  the new device is the structure of the shared negative electrode said Mitsubishi Electric.

The shared electrodes of the prototypes were made with carbon material. The first positive electrode of the capacitor part and the second positive electrode of the battery part made with activated carbon and material including iron phosphate (LiFePO4), respectively.

Japan ships 20% more solar batteries
The shipping volumes of solar battery cells and modules manufactured by Japanese companies (right).

Japan Photovoltaic Energy Association (JPEA) announced that the shipping volume of solar battery cells and modules made by Japanese firms increased by 20.5% on a year-over-year (YoY) basis to 1.387GW in 2009. Domestic shipments soared by 114.5% YoY to 483.96MW.

Overseas shipments declined by 2.4% on a YoY basis to 903.065MW. The domestic shipments of solar batteries have been increasing since 3Q 2009. with Japanese solar battery makers in full production.

In 4Q 2009, shipping volume was 460.567MW, an increase of 47.2% YoY. Domestic shipments were 190.748MW (YOY increase of 191.6%) Overseas shipments were 269.819MW (an increase of 9%).

By battery type, shipping volumes of polycrystalline silicon batteries, monocrystalline silicon batteries, thin-film silicon batteries and others including compound batteries increased by 28.6% YoY basis to 224.171MW, by 75% to 180.029MW, by 35.7% to 44.074MW and by 294% to 12.293MW, respectively.