Client: Vale Canada Limited
Location: Sudbury, Ontario
J.L. Richards & Associates Limited (JLR) was retained by Vale Canada to provide multidisciplinary analysis of energy systems at the Coleman Mine. The mine had several different goals for upgrades including: the development of a cooling system for fresh air ventilation of deep underground mining areas; an aggressive peak shaving solution to reduce electric bill global adjustment charges; upgrades to electrical circuits; and the reduction of greenhouse gas (GHG) emissions.
JLR’s multidisciplinary team proposed a list of eight possible technical solutions that would address one or more of the goals and developed an options analysis with matrix format to summarize and evaluate the best possible combination of solutions.
The analysis included thermal energy modeling of the ventilation heating and cooling loads for each of the thermal energy options, with concept design, sizing, and costing. Analysis included consideration of major constraints at the mine site (site layout, natural gas supply limitations, land availability, etc.).
The analysis of electrical systems included proposed solutions for power factor correction on multiple underground circuits, using traditional capacitor solutions and using a battery energy storage systems (BESS). The BESS concept was designed to provide three services on key underground circuits: power factor correction; back-up power; and demand reduction during grid peaks. A detailed model was also developed to evaluate the correlation of the solar photovoltaic (PV) generation profile with grid peaks. The use of BESS and/or PV in a behind-the-meter configuration was to reduce Class A global adjustment charges on the electricity bills.
JLR’s work provided conceptual design, operational performance evaluation, opinions of probably cost, GHG emissions, impact on peak demand, and financial return on investment of each option.
The results indicated that no one choice could accomplish all goals, but that there economically attractive solutions that in combination achieved all the goals. Preferred technology included a combined heat and power system with absorption chillers for cooling supply, a heat recovery solution between return and fresh air raises to reduce energy use and GHG emissions and a BESS and PV solar system for global adjustment peak shaving.