Authors headline the peak-period own-price elasticities as the robust significant results || "Estimates of own-price elasticities in the peak period are significantly different from zero for most of the industries considered. On the other hand, partial peak and off-peak own-price elasticities are not significantly different from zero except in a few industries." (p.101-103)
Chung, C., and D. Aigner (1981): “Industrial and Commercial Demand for Electricity by Time-of-Day: A California Case Study.” The Energy Journal 2(3), 91-110