Effective energy management starts with management, not with engineering. Managing energy has no meaning if it does not contribute to what your plant is doing. However profitable a project is, if it does not contribute to production, quality or safety, it will always be assessed on the basis of simple payback, like as if [...]
Simple payback is a misleading financial ratio. Conventional wisdom says that short payback is a sign of a better project. Wrong. Getting your money back is not a goal of an investment. The goal of investment is to make invested money make more money with minimum risk. Simple payback does not even consider risk of [...]
Every time I hear somebody say "project saved $12,345.67" I look if person's nose has grown a bit. Obviously such person does not understand the first thing about savings: energy savings is an avoided consumption, consumption that did not happen, nobody can measure something that did not happened. Energy savings are never exact, always [...]
When assessing energy savings, the use of math is not a substitute to engineering common sense. Math is an enhancement tool: if engineer has made in error – math will not correct it; math will make it bigger. Never mind calculations, statistical analysis or even artificial intelligence, if result does not make engineering sense [...]
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 used that is comprised off Global Adjustment (Ontario), demand charges (kW) and energy cost. It matters if avoided consumption contributed to consumption during monthly peak demand or not. Faults of [...]
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 [...]
