Solar-assisted hemodialysis

Abstract

Background and objectives: Hemodialysis resource use-especially water and power, smarter processing and reuse of postdialysis waste, and improved ecosensitive building design, insulation, and space use-all need much closer attention. Regarding power, as supply diminishes and costs rise, alternative power augmentation for dialysis services becomes attractive. The first 12 months of a solar-assisted dialysis program in southeastern Australia is reported.

Design, setting, participants, & measurements: A 24-m(2), 3-kWh rated solar array and inverter-total cost of A$16,219-has solar-assisted the dialysis-related power needs of a four-chair home hemodialysis training service. All array-created, grid-donated power and all grid-drawn power to the four hemodialysis machines and minireverse osmosis plant pairings are separately metered. After the grid-drawn and array-generated kilowatt hours have been billed and reimbursed at their respective commercial rates, financial viability, including capital repayment, can be assessed.

Results: From July of 2010 to July of 2011, the four combined equipment pairings used 4166.5 kWh, 9% more than the array-generated 3811.0 kWh. Power consumption at 26.7 c/kWh cost A$1145.79. Array-generated power reimbursements at 23.5 c/kWh were A$895.59. Power costs were, thus, reduced by 76.5%. As new reimbursement rates (60 c/kWh) take effect, system reimbursements will more than double, allowing both free power and potential capital pay down over 7.7 years. With expected array life of ∼30 years, free power and an income stream should accrue in the second and third operative decades.

Conclusions: Solar-assisted power is feasible and cost-effective. Dialysis services should assess their local solar conditions and determine whether this ecosensitive power option might suit their circumstance.

Figure 1.

Solar insolation data comparing the 12-month study period insolation means with the 2-decadal means for Geelong, Australia.