Experimental investigation of local clays and clay schemes as liners for solar ponds

Abstract

SUMMARYThis paper investigates the potential of using local clays and locally available materials as lining materials for solar ponds. Results for the liquid limit, the plastic limit, the plasticity index and the permeability were obtained for clays obtained from five regions in Jordan, namely Amman, Irbid, the Dead Sea, Karak and Tafilah. The results indicate that Amman clays have the lowest permeability values, making them a potential candidate as lining materials for solar ponds in Jordan. This paper also looks at various lining schemes for solar ponds, made of local clays and the other materials. The schemes were tested using saline water from the Dead Sea. It was found that an effective cheap lining scheme may consist of combinations of compacted local clay and locally manufactured low density polyethylene film sandwiched between the clay.

A critical reappraisal of residual soils as compacted soil liners

“…A salt gradient solar pond comprises three (3) zones: an upper convective zone (UCZ) of low salinity; a non-convective zone (NCZ) in the middle of the pond, with salinity that increases with depth; and a lower convective zone (LCZ) with high salinity at the bottom of the pond. A major drawback of the salt gradient solar pond is seepage through the soil, which simultaneously contaminates the soil and reduces the efficiency of the solar pond [102]. Studies have indicated that this challenge can be minimized by utilizing an effective barrier system around the inner surfaces of the pond.…”

“…French et al [103], Fynn and Short [104] and Hull and Nielsen [105], all reported the effective utilization of synthetic materials as hydraulic barriers for small prototype solar ponds. However, studies by [102] indicated that, if such synthetic liners are utilized in large solar ponds (in an area greater than 5 km 2 ) constructed for electricity generation, the cost of the solar pond increases by as much as 30%. Under such circumstances, local clay deposits can be effectively utilized as an alternative for reducing liner costs and simultaneously preventing soil contamination, especially in developing countries [106].…”

“…Their results revealed that an LDPE film sandwiched between two layers of compacted clay could be utilized effectively as liners for solar ponds. Researchers such as [102,106,107,109,110] indicated that utilization of compacted soils as a substitute for synthetic materials for liner applications in solar ponds could lead to a reduction in the cost of construction and the risk of pollution to the subsoil and groundwater.…”

Towards Solar Pond Design and Development for Masdar City Environment

“…A solar pond has been recognized as an attractive renewable and cost-effective method for medium to large-scale solar thermal energy storage [1][2]. It consists of a staggering three-layered water body of different salinity water that accumulates and store solar radiation as sensible energy [3].…”

“…Therefore, usage of chemically stable of low permeability lining is necessary. Economic challenges include the availability, stability, and high cost brine formulation [1][2]17]. Although commercially available sodium chloride salt is appropriate for making artificial brine [6], the reuse of rejected brine from desalination plant (RO, Flashing, MD etc.)…”