When businesspeople think about going solar, they often also think batteries. Batteries definitely have their place, but shouldn't ever be an expensive substitute for smarter energy management.

And smarter energy management must start with efficiency - eliminating waste, upgrading outdated equipment, optimising motors and drives, improving process controls, and streamlining energy use at every level. These improvements reduce underlying energy demand and increase the effectiveness of any solar or storage solution that follows.

However, the best kind of energy storage is often not storage at all. It is changing when and how you use your energy, so you need much less storage in the first place.

By making small operational or organisational changes, businesses, residential estates, and farms can shift major energy loads into the solar production window during the day, or into off-peak late-night tariffs. This flattens their morning and evening peaks and reduces the need for expensive batteries or backup systems.

Optimise first: shift your load

Before investing in any storage, it makes sense to first look carefully at your operations. What energy-intensive activities are happening during peak tariff hours that could be rescheduled?

Irrigation and pumping: Night-time water pumping for irrigation can often be shifted to the middle of the day when solar energy is abundant and where cost-saving benefits outweigh evaporation losses. This immediately reduces evening peak demand and cuts energy storage requirements.

Manufacturing shifts: In factories or processing plants, adjusting shift start times slightly can align production with solar availability. Starting earlier or later smooths out the load curve without needing batteries.

Bakeries and food processing: In bakeries, delis, and kitchens, oven preheating can be moved into lower tariff periods or use daytime solar energy ahead of evening operations.

Cooling and refrigeration: Pre-cooling cold rooms during the day can reduce compressor load overnight when grid tariffs are high and solar is unavailable.

In many cases, a simple operational change saves money and energy before any storage solution could.

As Sebastian Bode, Decentral’s head of technical, puts it: “We often see clients jump straight to batteries when where they really need to start is with smart metering and load optimisation. Once you have the data, it’s much clearer where small changes can make a big difference - with significantly lower costs of energy storage.”

Smart storage when load shifting isn't enough

Of course, not everything can be rescheduled. For those loads that must happen in morning and evening peak times, smart, low-cost storage options are available—and they are not always lithium-ion batteries.

Thermal storage: hot, cold and space heating

• Hot water: In residential estates, hotels, lodges, and staff accommodation, geysers and central hot water tanks can be charged during the day with solar energy. Hot water systems function as thermal batteries, storing energy as usable heat at a much lower capital cost than electrical batteries.
• Space heating: In colder regions or seasons, especially the Highveld’s chilly mornings and evenings, bisected by glorious winter sunshine, systems such as thermal mass heaters, water-based radiant heating, or phase-change panels can absorb solar heat during the day and release it at night for indoor comfort.
• Cold storage: In cold rooms and warehouses, cold-retaining liquids or phase-change materials can freeze or cool during solar hours and maintain low temperatures overnight. These materials absorb thermal energy during phase transitions, effectively storing "coolth."

Gravity storage for agriculture

On farms, solar-powered water pumps can fill elevated tanks or collector dams during the day. Irrigation can then happen at dawn or dusk with the help of gravity, reducing costly nighttime pumping. This simple mechanical storage method avoids the need for battery banks altogether.

Time-of-use tariffs make timing critical

Under Eskom’s restructured tariffs - such as Homeflex for residential users and Time-of-Use (TOU) tariffs for commercial and industrial users - electricity costs vary dramatically by time of day. In some tariffs, peak-time energy can cost three to five times more than off-peak usage. Shifting energy use into cheaper off-peak windows, and reducing consumption during expensive peaks, can have a major impact on operating costs.

Load shifting and smart operational planning are now just as important as investing in the right technology.

First optimise, then store

At Decentral Energy, we work closely with clients to optimise their energy profiles before recommending storage solutions. By rescheduling major loads to align with solar generation, businesses, farms, and estates can often significantly cut their storage needs.

Batteries have their place - and so do thermal and mechanical storage solutions. But the smartest strategy is always to reduce the need for storage first, and only then invest wisely where it truly adds value.

Sometimes the best battery is simply better planning. And we are here to help you make that happen.

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