Dealing With Peak Loads on the Grid – Ice Storage
Filed Under: Green Technology on November 27, 2009
In most areas of the industrialized world, the highest peak electrical loads are during the hottest summer days when air conditioning units are running full blast. In fact, about 75% of our total electrical energy is used by buildings and a large chunk of that is used for air conditioning, especially in the populous cities of the Southwest in the United States.
Most electrical grid design is built around servicing that peak period of electrical use between 09:00 and 19:00 every day in whatever locale the grid is servicing.
Ice storage is nothing new to the energy storage game. Usually, it is used to make ice during the cooler night-time weather (when electricity is “off peak” and generally cheaper) and to then use the ice during the day to cool air conditioning units or the air itself to take some of the load off of the electrical usage during the day.
Well, a company called Calmac has a more efficient way to make this happen.
Called the IceBank, these energy storage systems can store energy by absorbing it at night (making ice) and then using the cold ice to more effectively cool (air condition) a building. They’re able to cut 20-40% off of a building’s cooling costs. That’s pretty significant.
Think about it this way: let’s say a building uses 3kWh/hr to run its air conditioning. It does so for 8 hours a day, 5 days a week, for 6 months of the year. So (3kWh x 8) x 5 = 120kWh per week. That’s 480kWh per month, 2,880kWh per summer season (six months).
Saving just 20% of that drops it to 2,304kWh (-576kWh) and saving 40% drops it to 1,728kWh (-1152kWh). That’s significant. Multiply that by ten, twenty, fifty, or a hundred buildings and you can see the potential savings.
Of course, the IceBank isn’t using less energy overall, but it is using less costly energy. Another benefit is that many wind farms, especially in the Southwest, produce more energy overnight than they do during the day (cooler air at night often means better wind velocities). So the IceBank could be seen as a way to store wind energy to be used later: a battery for wind power.
It’s a sound idea and one that many large cities and urban heat islands could benefit from. You can learn more about it at the Calmac website.
Wondrous article! Storing and consuming energy that leads to cost cutting factor and saving energy for another usage is fabulous. I liked the way you have shown mathematical calculations for such saving factor. With more innovative ideas one can advance themselves in this type of consumption and storing packages.