Batteries cost US$80/kWh. 700° sand costs about US$1.25/kWh, though that depends on how far the sand has to be trucked. A normal stove burner is about 2kW and

Batteries cost US$80/kWh. 700° sand costs about US$1.25/kWh, though that depends on how far the sand has to be trucked. A normal stove burner is about 2kW and requires about 20 minutes to cook a meal for a person, so about 0.7kWh. Either of these is probably affordable in Ghana, where the national income is about US$2500 per person per year, i.e., US$200 per person per month. But the cost of the battery would be significant for an individual (one or two weeks of income), and the cost of the sand isn't.