We’re told to turn off lights to save electricity. But when you move up the energy chain, turning off the lights means saving water.
In turn, more water means more food. Nowhere is that more obvious than in California which grows one-half the fruit and vegetables in the U.S. and for much of Canada. The recent drought has prompted the California governor to order a 25 per cent reduction in water consumption.
As well, water produces electricity for many parts of North America. Water behind a dam is a versatile resource: energy, food, potable water. Turning off the lights can mean more food. In other words: energy = water = food.
Smart water can be achieved in a number of ways. One of the problems with renewable energy is storage. Solar panels and wind turbines produce electricity but not necessarily when it’s needed. What’s to be done with the surplus?
Sure, surplus renewable electricity can be stored in batteries or other devices. Another option would be to store the surplus energy as water. Once the water is pumped behind a dam, it can be used for electricity when it’s needed, or for food. Another option would be turn unusable groundwater into potable water. Michael Webber at the Energy Institute, University of Texas at Austin, puts it this way:
“We can also rethink how to better use energy and water to grow food in unlikely places. In parts if the desert Southwest, blackish water is abundant at shallow depths. Wind and solar energy are also plentiful. These energy sources present challenges to utilities because the sun does not shine at night and the wind blows intermittently. But that that schedule is fine for desalting water because clean water is easy to store for later.”
As climate change drives drought into parts of the Canadian prairies, that calculation applies here. Surplus renewable electricity could provide water to prairie towns that would otherwise dry up, providing drinking water and even irrigation for crops.
As well as turning off the lights, we could throw away less food to save water. It takes 15,000 litres of water to produce one kilogram of beef, 1,600 litres per kilogram of bread. Yet, we throw away about one-third of the food we buy. When you throw away 1/2 kilo of over-ripe apples, you’re throwing away the 400 litres of water it took to grow them. That represents more energy than a couple of lights turned off.
Too many perfectly good fruits and vegetables are thrown out because they have minor imperfections. Restaurants throw out tonnes of food from the plates of customers who order more than they can eat. But even if more cosmetically imperfect food was consumed and plate portions were reduced, some waste may be unavoidable.
Instead of throwing waste food into landfills, it could be placed in anaerobic digesters along with other agricultural waste such as manure to produce methane, which could be used to produce electricity, which could be used to pump water, which could be used for . . . well, you get the idea.