How to Make Off-Grid Solar Electric Cooking Cheaper Than Wood-Based Cooking

Robert Van Buskirk,Christina Gilbert,Lawrence Kachione,Gilbert Robert,James Majoni,Rachel Kanyerere

doi:10.3390/en14144293

Robert Van Buskirk, Christina Gilbert + Show 4 more

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https://doi.org/10.3390/en14144293

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Journal: Energies	Publication Date: Jul 16, 2021
Citations: 9	License type: CC BY 4.0

Affiliation: Museum of Malawi

Abstract

Low-income sub-Saharan Africa (SSA) households rely on wood for cooking for the simple reason that it is the lowest cost cooking fuel. Thus, full attainment of Sustainable Development Goal 7 (SDG7) requires developing clean cooking technologies that are cheaper than wood cooking. This study provides a comparative marginal levelized cost of energy (MLCOE) analysis for wood cooking vs. innovative solar electric cooking technologies. The two key off-grid solar technologies evaluated are: (1) direct-use DC solar (DDS) electricity for cooking applications, and (2) high-cycle-life lithium titanate (LTO) batteries. MLCOE is reported in USD/kWh for energy delivered to cooked food. A low median MLCOE of USD 0.125/kWh is attained using DDS electricity which is output directly by a solar panel with little or no intervening electricity storage and few electricity conversion and control costs. DDS solar panel output has variable voltage and current that is managed by a specialized DDS cooker. LTO battery-regulated electricity has a median MLCOE of USD 0.24/kWh which declines to USD 0.16/kWh with electric pressure cooker use. The distributions of MLCOE for wood-based, DDS-electric, and LTO-electric cooking strongly overlap. The MLCOE cost model suggests specific means for modifying input costs, component lifetime, and system efficiency to improve solar MLCOE further relative to wood MLCOE.

Highlights

There is an extensive academic literature that discusses what may be required for attainment of affordable and clean energy for all, i.e., Sustainable Development Goal 7 (SDG7)
This study has presented an analysis of how solar electric cooking can be costcompetitive with wood-based cooking in sub-Saharan Africa (SSA)
Approximate targets for each of these cost parameters for solar electric cooking (SEC) are roughly as follows: (1) >10 years for solar panels and battery subsystem lifetime, (2) solar panel costs below USD 0.36/Wp and LTO battery subsystem costs below USD 0.35/Wh, (3) solar panel utilization efficiencies of greater than 25%, and (4) a valuation or subsidization of climate benefits that exceeds USD 20/ton of CO2-equivalent emissions (tCO2e)

Summary

Introduction

There is an extensive academic literature that discusses what may be required for attainment of affordable and clean energy for all, i.e., Sustainable Development Goal 7 (SDG7) Much of this literature contends that attaining SDG7 will require investment in clean energy infrastructure that is high cost compared with incomes of the populations that currently lack affordable clean energy supplies. A 2020 study that provides projections of microgrid electricity costs as a function of supply reliability provides a projection that the costs can be as low as USD 0.30/kWh by 2025 [12]. The per-kWh cost of solar home systems can be an order of magnitude higher than microgrids because of the shorter lifetime, low system capacity utilization, and decreased economies of scale [13]

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