Plantmargin blog

Practical notes on energy, fuel, production cost and compliance for plants in Uganda.

Cost per unit by production lot: let the best shift set the standard

Why monthly averages hide the biggest saving in most plants, and how lot-by-lot costing turns it into a target.

26 October 2026 · 1 min read

Battery or generator for backup power: the honest comparison

When a battery pays for itself as backup, when a generator is still the better answer, and why many sites end up with both.

26 October 2026 · 1 min read

Steam and boiler losses in tea, dairy and sugar plants

Excess air, stack temperature, failed traps and blowdown: where boiler fuel goes, and the measurements that find it.

19 October 2026 · 1 min read

Is your solar plant performing? Performance ratio and soiling explained

How to tell whether a solar system is producing what it should, using performance ratio, specific yield and inverter-by-inverter comparison.

19 October 2026 · 1 min read

Sizing solar from your own meters, not from a guess

Why the hourly load shape decides the right solar size, and how a metered profile changes the answer compared with the monthly bill.

12 October 2026 · 1 min read

Variable speed drives on fans and pumps: a practical payback guide

Why throttling with dampers and valves wastes energy, how the affinity laws estimate the saving, and what to measure first.

05 October 2026 · 1 min read

Power factor correction: when it pays, and how to size it

How a low power factor costs a plant money, and how to size a capacitor bank from measured data rather than rules of thumb.

28 September 2026 · 1 min read

Grid-tied, hybrid or off-grid solar: choosing the right system for a plant

The three types of solar system, what each one does in an outage, how each is sized, and which sites each one suits.

28 September 2026 · 2 min read