What is the term ice accumulation?

  And the process of making ice and storing it in large tanks during the night when electricity is cheaper. The manufacture of this ice is done by passing a solution of water and ethylene grade at about -4C through insulated tanks with pure water. This pure water will freeze at 0C. This ice is used during peak times (6 pm to 9 pm), turning off the compressors and circulating the ice water through them.