What a Power Outage Really Costs Your Factory

Most CFOs know their factory's cost per kWh to the decimal, yet almost none can say what one hour of downtime costs in baht — because that cost is spread across five buckets that never get added up. Fill the worksheet below with your own real numbers; you don't need precision, just the right order of magnitude to see the picture.

* Illustrative framework only — figures depend entirely on your production line, margins and outage duration. Plug in your own numbers. Not a guarantee of loss or savings.

Illustrative ฿/hr cost of downtime by factory type

Not every factory hurts equally when the power drops. This table ranks the relative severity-per-hour by production type — not fixed baht figures — so you can place your own plant on the scale, then plug your real numbers from the worksheet above.

* Illustrative bands only — your real ฿/hr comes from the worksheet above. This table shows relative severity, not a guarantee of loss or savings.

Once you have a per-event cost, annualise it: (typical events/yr × THB per event) = an annual downtime exposure that never appears as a line item, because it hides inside production cost, overtime and scrap. Look at that figure before concluding 'we don't need backup power.'

So the right frame isn't 'how often does power fail' but 'if it fails, how much do we lose, and how much of that risk can we tolerate.' Solar + battery + microgrid don't make outages impossible — they reduce the exposure and keep critical loads alive through a grid drop.

To be straight: we are not claiming Hormuz will black out your factory tomorrow, and we are not manufacturing panic. What genuinely changed is that tail risk — the probability of a long-tail event — is higher. In that environment, putting in place a hedge that reduces both your ordinary electricity cost and your outage exposure is worth more than waiting for the event to arrive first.

Layer 1 — rooftop solar self-consumption: cuts grid dependence in daylight hours. Every unit you generate is a unit you don't buy from the grid. But understand the limit clearly — an ordinary grid-tied solar system does NOT keep feeding power when the grid drops, because anti-islanding standards force the inverter to trip instantly to protect line crews. So solar alone lowers your bill but is not a backup system. For the economics of adding storage, see BESS battery storage for factory solar.

Layer 2 — battery storage (BESS): bridges the gap when the grid drops, from seconds (ride-through that prevents batch spoilage) to hours (carrying critical loads). Layer 3 — microgrid + islanding: lets the factory disconnect from the grid when the grid fails and keep running on solar + battery + generator in its own closed loop, so critical loads (cold rooms, cleanrooms, servers, PLCs) stay alive. For the architecture and islanding design, see factory microgrid solar + battery.

CapSolar is a Thai-based solar EPC and PPA company. We have delivered 80+ MWp across 150+ industrial projects for 100+ clients, reducing 85,000+ tons of CO₂ — operating-EPC ground-truth, not consultant estimates. Our engineering team designs solar self-consumption, battery storage and microgrids for factory critical loads — both self-owned and zero-capex PPA.