KIBBUTZ YAHEL, ISRAEL—The southern tip of Israel is a rocky desert where solar panels are abundant and the sun, when shining, is the source of nearly all electricity. Once it sets, however, the grid shifts back to fossil fuels to generate power. Renewable energy from solar and wind powered systems cannot be stored without extra cost. But at Kibbutz Yahel, a small community not far from the Red Sea where a sweet variety of dates called Medjool is grown, residents have started using a new technology that can store solar energy cheaply and produce power well into the night. During the day, excess energy from solar panels drive a system where water is used to condense air in underground tanks. After sundown that air is released to power a turbine and generate electricity. And the cycle repeats in the morning. “Other kibbutzim are waiting and watching to see if this …