For the last seven years, IEA PVPS Task 8 (Very Large Scale PV), has been something of a voice in the wilderness, quietly progressing its analysis of the feasibility of multi MW to GW scale desert-based PV systems. However, if the level of interest in the VLS-PV work experienced at the recent European PV Solar Energy Conference in Dresden is any indication, desert PV really could be ‘the next big thing’.

Task 8’s publication of its latest book ‘Energy from the Desert: Practical Proposals for Very Large Scale Photovoltaic Systems’ is timely. There is considerable interest in PV investments at the present time and the emerging trend is towards installation of ever larger PV systems, particularly in those markets where favourable feed-in tariffs are on offer.

The new book, a summary of progress during Phase 2 of the VLS-PV Task over the past three years, provides encouragement for those interested in large centralized PV systems, asserting that, based on existing PV technology, VLS-PV could directly compete with fossil fuels as the principal source of electricity for any country that has desert areas. At the same time there are some caveats, notably that, as a financial investment, at present PV system prices VLS-PV is still reliant on additional incentives such as high feed-in tariffs to be viable. Module costs account for a very large proportion – up to 75 % – of the total cost of VLS-PV systems so developments in this area offer the main potential for future cost reductions and more widespread economic viability. On the positive side, the development of cells and modules with higher conversion efficiencies, and other technical innovations in areas such as hydrogen production and high-temperature super conductors, are all conspiring to make VLS-PV projects increasingly attractive.

As reported in PV Power #24, Task 8’s work has focused on proposals for the Mediterranean region, the Middle East, Asia (China and Mongolia) and Oceania. Each region has been tackled in a slightly different way with for instance the Mediterranean project analyzing PV generation costs against available feed-in tariffs and conventional electricity prices in Spain, Portugal and Tunisia based on respective local irradiation and using current best system prices for large-scale plants. On this basis, Spain emerges as a potentially viable market for VLS-PV in the next 2 to 5 years.

In the Middle East, a ‘Top-Down’ approach for the introduction of VLS-PV Systems has been considered. This focused on land availability for solar harvesting, electricity requirements, technology optimization and rate of deployment and the financial implications of VLS-PV. An example for Israel assessed the construction of production facilities for existing concentrator PV technology building to an annual capacity of 1,5 GW within 4 years, coupled to an annual addition of 3 GWh of storage (0,5 GW for six hours). The case study found that the credit line necessary to achieve this level of VLS PV installation would be fully repaid after 21 years by which time revenues would be sufficiently high to enable both the continued annual production of VLS-PV plants with no further investment, and the decommissioning and replacement of old plants after 30 years of service. This is an important observation, as after the initial investment has been paid off the price of electricity no longer depends upon any factors related to its generation. It becomes a purely arbitrary figure that can be fixed at any desired level.

The third phase of Task 8 is now commencing and will continue until 2008 further developing specific case studies as well as general instructions for the implementation of practical project proposals. The results are certain to be of widespread interest.

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