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 [...]
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 [...]
Performance of every piece of machinery degraded with time. This may cost your plant thousands of dollars in lost production, rejects, and energy. Recommissioning can solve this problem, but it costs time and money. When is recommissioning worth the effort? Energy costs of performance degradation Degradation may be caused by a wide range of [...]
Companies that buy new equipment to avoid Global Adjustment charges face risk of having stranded assets. Business case for investments in GA avoidance equipment - generators and batteries - relies on current GA model, which resulted from a political decision. GA regime is based on politics, which are reliably unreliable As we all know, [...]
1. In metering we trust :) Data is only reliable if it has been collected through routine automatic metering, which has been validated. All claims like 'we always keep this operational schedule', 'compressor/boiler/light is off on weekend' or 'current never exceeds X Amp', all of them have exactly zero value to energy [...]
During quarantine time many plants face uncertain work load and even less certain revenue. The simplest way to save energy and cost to turn unnecessary machines off. This simple recommendation is rarely easy to implement, it's even more difficult to monitor. How to find if unneeded machines are turned off without breaking a bank? [...]
