To be effective energy management project must start with goals to be achieved, not tools and technologies available. 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 [...]
Simple payback is a misleading financial ratio. Conventional wisdom says that short payback is a sign of a better project. Wrong. The goal of an investment is not to get your money back, but to make invested money make more money with minimum risk. Simple payback does not even consider risk of not getting money [...]
Every time I hear somebody say "project saved $123,456" I look if person's nose has grown a bit. Obviously such person does not understand the first thing about savings: energy savings is consumption that did not happen, nobody can measure something that did not happened. Energy savings are never exact, always an estimate. 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 just calculations, statistical analysis or even artificial intelligence, if result does not make engineering [...]
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 the time during 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 [...]
Calculating energy savings results is like keeping a golf score. If you ever been on the green, understanding the meaning of CUSUM will come easy. Baseline - how machine is supposed to work or worked before retrofit - is a par. CUSUM - a cumulative sum of deviations from baseline - is a score. If [...]
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 the highest correlation (R2) between predicted and measured data. In a vast majority of cases relation between energy consumed and it's driver is [...]
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 [...]
