When a baseline built over a certain period has R2=95%, it means that baseline formula accurately predicts actual consumption in 95% of cases within this period. This does NOT mean that there were no changes during this period. The wrongly predicted 5% of data points may be measurement noise or data collection error or [...]
Calculating energy savings results is keeping like golf score. If you ever been on the green, understanding the meaning of CUSUM is trivial. Baseline - how machine is supposed to work or worked before retrofit - is a par. CUSUM - a cumulative sum of deviations from baseline - is score. If CUSUM is above [...]
When determining energy consumption baseline through regression analysis, as recommended by best practices, sensible energy managers pick a formula that relies of physics of the process, not a formula that produces high correlation (R2) between predicted and measured data. In vast majority of cases relation between energy consumed and it's driver is linear. Here [...]
Use of average electricity cost can be misleading when assessing financial impact of energy efficiency measures. What counts is the cost of the last kWh comprised of Global Adjustment (Ontario), demand charges and energy cost. If average cost per kWh is used during project approval, it may become a challenge to show savings to [...]
If your plant underproduced today, you may be able to catch up with schedule by working overtime tomorrow. If you wasted energy today, it is gone forever. No effort tomorrow will help to recover it. Timely action is the key to stop waste before it became to big. Do you know how much energy [...]
Monthly electrical bill is as good for energy management as a summary of monthly bank statement is for financial management: too little of data to understand what happened and too late to act. Summary of bank statement shows balance of account: sum of deposits and sum of payments. If you have spent too much or received [...]
