Photovoltaics (PV) shares the same key locational requirement as CSP; it too is best located in very sunny environments, such as deserts. PV is simple to operate and highly scalable, but lacks the capacity for low-cost direct energy storage that is characteristic of CSP. For the purposes of the Sahara Forest Project, it also does not generate heat, which is of value for the greenhouse operations and water distillation processes. However, in some circumstances this need might be met in other ways – using direct solar thermal collectors, or by taking waste heat from a nearby industrial source – and there are other synergies between the Sahara Forest Project concept and PV parks that may make a technological partnership attractive. These include:
- Dust reduction. PV facilities elsewhere in the Middle East have suffered from very rapid dust accumulation on the panels, which requires very frequent labour- or water-intensive cleaning. By revegetating areas around and under the PV panels, the Sahara Forest Project will provide local dust arresting, while trees and earthwork will provide protection from wind and the dust carried with it.
- Panel cleaning. The SFP’s saltwater-cooled greenhouses can produce distilled water to wash off whatever dust does gather on the PV panels, increasing the electrical output of the system by a few percent.
- Efficient land use and additional revegetation. Some plant species are likely to benefit from the shelter and shade provided by the PV panels. There is no fire risk associated with growing plants under the PV array, and doing so allows for dual-purpose land use that can improve project economics. Moreover, planting below the panels allows for direct recycling of cleaning water for irrigation without need of a costly water reclamation system, as that water will simply drip into the crops below.
- Infrastructure sharing. In many regions, there are significant development and infrastructure costs associated with obtaining planning permissions and local and national support for a project, as well as with bringing the necessary services to a commercial site in the desert. The Sahara Forest Project can provide a vital political, logistical, and developmental context to a PV facility.
