Backing up your business: what to look for in a commercial solar system

Domestic solar is bought on comfort and savings. Commercial solar should be bought on arithmetic — because for a business, both the electricity bill and the cost of an outage are measurable.

That makes the decision easier than it looks, provided you start from the right question.

Start with what downtime actually costs

Before looking at any equipment, work out what an hour without power costs your business. It is rarely just lost trading.

A shop or supermarket loses sales, and if refrigeration is involved, stock. A freezer that thaws is not merely an inconvenience.

A clinic may have treatments that cannot be interrupted, vaccines with a cold-chain requirement, and a reputational cost that outlasts the outage.

A school loses teaching time and, if it boards, the ability to feed and light students safely.

A workshop or small factory loses production, may waste material mid-process, and pays staff who cannot work.

An office loses productivity, and possibly customers who cannot reach anyone.

Put a figure on it per hour. That figure — not the price of a battery — tells you how much backup is worth buying.

Then look at when you use power

This is where commercial solar has a structural advantage over domestic.

A business running from eight to six consumes electricity while the sun is shining. Generation and demand line up naturally, so a large share of what you generate is used immediately rather than cycled through a battery and back out. Every cycle avoided is money not spent on storage and energy not lost to conversion.

A household, by contrast, uses most of its power in the evening — after generation has stopped — which is why domestic systems lean so heavily on batteries.

If your load profile is daytime-heavy, the economics of solar are better for you than for almost any home. Ask KPLC for your consumption data, or read a year of bills, before deciding anything.

Three architectures, three commercial cases

Grid-tied, no battery. Cheapest per kilowatt. Cuts the bill, does nothing during an outage. Right for a business with a reliable supply where the objective is purely cost reduction.

Hybrid with partial backup. Solar and battery, with only critical circuits backed up. Cuts the bill and keeps the things that must not stop running. Right for most Kenyan businesses.

Full backup. Everything continues through an outage. Considerably more expensive, and only justified where the whole operation stops without power — some clinics, some processes, some data-dependent operations.

Most businesses over-specify here. Ask which circuits genuinely cannot stop, and back up those. The tea urn and the car park lighting can wait.

Sizing for a business is not sizing for a house

Peak demand and starting surge dominate. Commercial sites run motors — refrigeration compressors, air conditioning, workshop machinery, pumps. These draw several times their running current on start. An inverter without adequate surge capacity trips, and a business that trips repeatedly stops trusting the system.

Three-phase is common. Check your actual supply before specifying. Some equipment requires three-phase and some sites have it without needing it.

Load profile beats a single number. A daily total conceals whether consumption is smooth or spiky. Spiky loads need more inverter; smooth ones need more panel. Get half-hourly data if you can.

Power factor and harmonics matter at scale. Sites with substantial motor loads or variable-speed drives can present a difficult electrical environment. This is a survey question, not a web-form question.

If you already run a generator

Most Kenyan businesses with a continuity requirement already have one. Solar rarely makes it redundant — but it usually makes it much cheaper to own.

Many hybrid inverters accept a generator input and manage it intelligently: solar first, then battery, and the generator only when both are exhausted. Instead of running for the whole outage, the generator runs for the part that solar and battery could not cover.

For businesses with long or frequent outages, this is often where the fastest payback sits — not in eliminating the generator, but in dramatically reducing its running hours and fuel bill.

What to insist on in a commercial quotation

A load study, not an assumption. Anyone quoting a commercial system without examining your consumption data or metering your site is guessing with your money.

A single-line diagram. It shows how the system connects to your existing switchgear, what is backed up and what is not. If you cannot see this, the design has not been done.

Named equipment with model numbers. You cannot check warranties, read datasheets or verify compatibility without them.

Protection specified explicitly. DC and AC surge protection, correctly rated breakers, combiner boards and earthing. Commercial arrays are large and exposed; this is where an under-priced quotation hides its savings.

Monitoring. You should be able to see production, consumption and battery state. Without it you cannot verify the system is delivering what was promised, and you will not notice a failed string until the bill tells you.

A clear scope boundary. Who does the switchboard work, the civil work, the roof strengthening if needed? Ambiguity here becomes a dispute later.

Structural confirmation for the roof. Commercial roofs vary enormously. Some need strengthening before an array is mounted, and that must be established before installation day.

Phasing the investment

Commercial systems can sensibly be built in stages, and often should be.

Stage one: array and inverter, attacking the bill. This is where the return is clearest and fastest.

Stage two: storage for continuity, once the savings from stage one are demonstrable.

The critical decision is at stage one: choose an inverter with the headroom and battery capability for what you intend to add. An inverter that cannot accept storage later means replacing the most expensive component to expand.

Warranty and support are commercial terms

For a household, a warranty is a safety net. For a business, support is an operational requirement.

Ask what happens when something fails: response time, whether replacement units are held locally, who attends site. A five-year warranty from a manufacturer with no Kenyan presence is a different proposition to one from a brand with local stock and local engineers.

The honest summary

Work out what an outage costs you per hour. Get your real consumption data. Decide which circuits genuinely cannot stop. Then buy the system that addresses those facts — which is often smaller and more targeted than the one you would be sold by someone working from a floor area.

For commercial systems we survey before quoting, because at this scale the difference between a designed system and a specified one is the difference between an asset and a recurring problem. Request a quotation with your consumption data and what you are trying to protect, and we will start from there.