Cured ham is one of the most energy-hungry foods you can produce. For months, every piece hangs in rooms where temperature and humidity must be controlled day and night, through every season. Cooling, heating and dehumidifying, often all at the same time, add up to an energy bill that can decide whether a plant is profitable or not.

In the early 2010s I ran an energy service company in Spain. Our model was simple: we measured how much energy a plant really used, designed the improvements, financed them, and were paid from the savings. If the savings didn’t appear, neither did our income. That forces you to be honest with the numbers.

What we found

In the drying rooms we audited, a large part of the energy was being wasted in three ways: [cooling and reheating the same air to remove humidity; fans and compressors running at full speed regardless of the real load; and heat being rejected outside while boilers produced heat for the same process].

What we changed

•           Heat pumps to recover the heat the refrigeration system was throwing away, and use it for reheating and drying.

•           Variable-speed drives on compressors and fans, so they deliver only what the rooms actually need.

•           Better control of temperature and humidity, so the systems stop fighting each other.

The results

Across [three] contracts we measured and verified savings of more than [850,000] kWh per year, following international measurement and verification (M&V) protocols. Depending on the plant, the energy bill came down between 10% and 32%. In March 2014 La Vanguardia’s Energy Efficiency supplement interviewed me about these results, and the work received [an honourable mention for energy savings and efficiency].

What I take from it today

The lesson travels well. Whether it is a drying room in Spain or a cold store in Africa, most energy is not lost in the big machines; it is lost in how they work together. Measure first, recover the heat you already have, let the equipment run at the speed the process needs, and verify the savings. In countries where every kWh comes from an unreliable grid or a diesel generator, that discipline is worth even more.