For Business and Homes · Off-grid solar
Off-grid solar for a site without a reliable grid connection
An off-grid solar system is not connected to the utility at all: panels, a battery bank and usually a generator carry the whole load, so it suits a site with no supply, or a supply too poor to rely on. KTronics designs and installs off-grid systems for homes and for businesses alike — a house beyond the last pole, an estate bungalow, a farm, a site office or a pumping station — with its own engineers in the Colombo, Gampaha and Kalutara districts and island-wide work beyond them.
Sized from the load, not from the roof
An off-grid system earns nothing from the grid and has nothing to fall back on, so it is sized from the load and the hours it must run unaided. Two numbers decide it. The first is daily consumption: every load that will run, how many watts it draws and for how many hours, added up into watt-hours a day. The second is autonomy: how many days of poor sun the battery must carry without the generator. From those come the battery capacity, the array needed to recharge it in an ordinary day, and the inverter size, which is set by the largest loads that run at the same time.
The battery bank
The battery carries the site from dusk until the array produces again, and through every cloudy day inside the autonomy you chose. We use lithium iron phosphate (LiFePO4) batteries, built for thousands of charge cycles and a safe, stable chemistry for daily use. Capacity follows from the daily consumption and the days of autonomy, with a margin so that the bank is not run flat on an ordinary wet day.
A generator as backup, where it is needed
A site that cannot be without power through a long run of wet days needs a generator behind the battery. The system signals the generator to start when the battery gets low; the generator recharges the battery and supports the load, then stops once it is no longer needed. Where a generator is already on site we connect to the auto-start controller it has, and we check the controller actually fitted before quoting, because look-alike controllers are common and we wire from what is on your panel, not from a brochure. Every installation keeps a local lockout so the engine cannot be started remotely while someone is servicing it.
Monitoring after handover
An off-grid site is usually the one nobody visits, so it is the one that most needs watching. The system is connected to our own monitoring platform for the term of the maintenance agreement: it is read daily, a fault raises an email when it happens, and every Sunday you receive what the system produced that week, that month and that year. Ten years on every device we supply is our own undertaking, and a maintenance agreement is honoured wherever the system is: we respond to a reported hardware breakdown within six hours, an authorised person attends site within three working days, and where the failed part is one we stock we aim to resolve within five working days.
No utility agreement, and no income from the grid
An off-grid system never runs in parallel with the grid, so there is no Net Plus agreement and no export meter — and it earns nothing from the grid. Where a supply exists but fails often, a hybrid system, grid-connected with a battery for the cuts, is often the better fit. Which one fits is decided at the survey: by how often your supply fails, what must stay on when it does, and what the roof and the connection allow.
What we need from you
- A list of every load that will run, with its wattage and the hours a day it runs
- How many days of poor sun the site must get through without a generator
- Whether a generator is already on site, and a photograph of its controller
- Where the site is, and how it is reached
Based in Kelaniya, with our own engineers covering the whole Western Province — the Colombo, Gampaha and Kalutara districts. Beyond it we work island-wide, with projects delivered as far as the Galle and Kandy districts.
Site assessment
Tell us about the site
Where it is, what has to run and for how long — an engineer will come back with what an off-grid system would involve. For a home or a business; no obligation.