At our 40 acre walnut orchard in Northern California, we water via two wells (30 foot water depth) powered by two PG&E-powered electric pumps (60hp and 20hp).

At our 40 acre walnut orchard in Northern California, we water via two wells (30 foot water depth) powered by two PG&E-powered electric pumps (60hp and 20hp). There is an agricultural discount if we run them nights and weekends, so we typically run them on weekends for 12-24 hours. Summer daytime temps are often 90-95 degrees F. Nighttime watering is also helpful due to less water evaporation. But given the duck curve, I expect PG&E will at some point encourage 10am to 3pm power usage. Then it might be cheaper, electricity-wise, to run the pumps 3 times a week, during the heat of the day, instead of overnight on weekends. Bad: More evaporation, so more water use. Good: Maybe cheaper, and since trees reduce their photosynthesis when it gets too hot (to decrease water loss), daytime watering may increase growth by keeping the air temperature lower.