Solar equipment for sites with no reliable mains: specify the load, not the panel

Solar enquiries almost always arrive specified by panel wattage. That is the wrong end of the problem. A solar installation is specified from the load it has to serve and the hours it has to serve it, and the panel array is the last calculation rather than the first.

The load profile, not the load

Two sites drawing the same daily energy can need completely different systems. What matters is when:

• A load that runs during daylight - irrigation pumping, daytime processing - needs comparatively little storage, and that makes it much cheaper per unit delivered.
• A load running into the evening needs storage sized for those hours, and storage is the expensive part.
• A load that must never be interrupted needs storage plus a backup source, which usually means generation in the same project.

Send the loads with the hours they run. That is enough to size a system honestly.

Storage is where systems fail early

The commonest disappointment with solar in our markets is not the panels, which are durable and well understood. It is batteries that lose capacity faster than expected, and the two causes are chemistry chosen on price and heat. Lead-acid in a hot climate on a daily deep cycle has a short and disappointing life; lithium iron phosphate costs more and survives the duty. Where a system is going somewhere hot and will cycle daily, that difference is the single most important decision in the specification, and it is worth paying for.

Ask any supplier what chemistry is quoted, what the expected cycle life is at your ambient temperature, and what a replacement costs and when it would arrive.

Where solar belongs with the rest of the equipment

Solar is rarely the project. It is usually the supply for something else: a water treatment installation, a processing site, an irrigation scheme, a three wheeler fleet that has to charge. Sizing the supply against the real equipment rather than against a nominal figure is the difference between a system that runs the site and one that supplements it.

Conformity

Solar equipment sits inside several destination conformity schemes where general machinery does not. Ethiopia's closed product list includes stand-alone solar products up to a stated wattage. Several other markets schedule electrical equipment specifically. So for this division, as for generating sets, the HS code and the destination are the first questions, because they decide whether a certificate is needed before shipment.

Send your loads with their running hours and the site location. Request a quotation, or see the solar range.