Why are R&D needed for photovoltaics
Why aren't more PV modules in regular use?
Because photovoltaic solar energy conversion is the most expensive form of renewable energy today. The cost is still far too high when compared with conventional electricity production.
Why do we need research?
- PV has the potential to cover the total world energy demand.
- It could make a major contribution to the reduction of CO2 emissions. However, sustainable energy production is only viable if the cost can be considerably reduced. Research and technological development will play a key role in bringing this about.
What research is necessary for PV?
- Material and manufacturing costs are the two major factors that influence the price of PV cells. Even though silicon is the second most abundant material on earth, the silicon used for PV cells must be very pure. In addition, the current manufacture of PV cells is labour and capital intensive, although methods of automation are being developed. How quickly PV becomes cost-effective depends on whether research can solve these material and production problems.
- A further major problem to be solved is the intermittent character of PV electricity production. Electricity supply has to be adapted to demand by storage systems or combined systems in which PV is used together with small power systems, such as fuel cells.
Why is EU support necessary?
- The competitiveness of the EU industry is a major issue in this rapidly increasing market. Currently, European industry is lagging behind the US, which exports PV components to the EU. Increased research support as well as new policies on RES penetration are prerequisites to bridge the gap.
- The EU added value for PV is high, as there is a high level of PV research activity in most Member States. Co-operation between the EU Research Programmes and those of Member States could help to achieve a critical mass and provide a complementary approach. In addition, standardisation of the technology will require a common EU approach.
Bottlenecks and barriersWhat are the issues that need to be addressed?
- The reduction of PV costs, which will happen as a result of increased automation in manufacturing, the production of new types of cells and an increase in the lifetime and efficiency of the complete PV system.
What are the major technical barriers to be overcome?
- High Cost: Research should be aimed at reducing both module and system costs
- Technology limitations of crystalline cells: Alternative production processes need to be developed which will reduce the processing steps, improve the manufacturing line and make better use of the expensive equipment.
- Acceptability of thin-film technology: Research should be conducted to overcome the drawbacks of thin-film technology, namely its relatively low efficiency and toxicity in production and disposal, and the need to increase its expected lifetime.
- Storing the electricity: Research into new electricity storage technologies should be adapted for photovoltaic use. Questions on the reliability, maintenance and ease of use in stand-alone applications and processes, which both convert and store electricity, need to be addressed.
What are the major non-technical barriers to be overcome?
The liberalisation of the energy markets, which will mean that with increased competition, energy companies will be reluctant to invest in new, risky, sustainable technologies.
Making the technology socially acceptable.
What are the research priorities in this area?
The main long-term objective is a module cost of 0.5€/Wp. In order to achieve this research should be focused on:
- Crystalline silicon cells and modules;
- Thin-film cells and modules;
- Advanced system technologies;
- In the future, more emphasis should be placed on the socio-economic aspects and benefits to be derived from the increased use of photovoltaic electricity.
How can the cost of PV be reduced?
- Through increased production capacity. According to the EU White Paper on Renewable Energy Sources link 1, the PV system cost is expected to decrease to below 3€/Wp by 2005, with a resultant PV electricity cost of around 0.15€/kWhr.
- Further options for cost reductions are:
An increase in the lifetime of PV systems from 20 to 30 years;
Greater use of higher insulation in the southern EU countries;
- In the long term an increase in levels of efficiency by between 30% and 50%.
In densely populated areas, south-facing roofs, facades of buildings and even windows should be used for PV electricity production. PV components could be designed to replace tiles, windows, and walls.