Off-Grid Microgrid Customization
off-grid microgrid engineering for sites without reliable mains for islands, mining sites, oilfields, pastoral regions and telecom bases.
Off-grid customization: turning the genset back into a backup plant
The hard part of an off-grid system is not generating power — it is surviving the worst few days: consecutive overcast weeks, storm season, a winter peak at a remote wellhead. We size against the worst month rather than the annual average, define sub-cycle transfer and load shedding by priority, and let the genset run only when it truly has to. Islands, mines, oilfields, farms and telecom sites each have a proven path with us.
- 8–72 hAutonomy configurable per project
- 60%–90%Diesel displacement typically achieved
- below 10 msUninterrupted transfer on internal-STS models
- 3–7 daysUsual renewable self-sufficiency design window
1. Where it fits
Three numbers decide whether off-grid storage makes sense: annual consumption, landed diesel price and resupply interval. The more remote and expensive the logistics, the stronger the case.
Islands and coastal villages
Desalination, cold chain, guesthouses and community loads, with salt-mist corrosion and low storm-season irradiation to manage.
Mining and construction camps
Crushers and hoists create three- to sevenfold inrush; the camp load is strongly day/night, ideal for storage.
Oilfields and pipeline nodes
Pump jacks are cyclic impact loads; sites are scattered, unmanned and need remote supervision.
Farms and ranches
Irrigation and milking cluster in the morning and evening; land is available for ground-mount PV plus containerised storage.
Telecom and repeater sites
Small load, zero tolerance for outage; IP65 wall-mounted units with remote battery health management.
Border posts and emergency supply
Silent operation, low thermal signature and fast deployment, optionally supplemented by mobile storage units.
2. First fork: DC-coupled or AC-coupled
This decision shapes the equipment list, the round-trip efficiency and every future expansion.
DC coupling
PV joins a DC bus before a single inversion.
Solar only needs one DC/DC and one DC/AC stage, so round-trip losses are lower and gensets can stay stopped for long stretches. The trade-off is that the PV controller participates in system control and AC-side expansion is less flexible.
- Fit: high renewable share, genset purely standby
- Fit: PV and storage built together in one phase
AC coupling
Each subsystem stands on the same AC bus.
You can start from a genset with modest storage and add PV capacity later. Several of our platforms support both coupling modes, so a mixed first phase can grow in either direction.
- Fit: staged build or an existing genset already on site
- Fit: sites where the load may grow substantially
3. Five things that decide success
Size to the worst month, not the annual mean
Take the worst consecutive three to seven days of historic irradiation or wind as your floor, then derive how long storage must carry and how much the genset must cover. Systems sized on annual averages come out visibly too small.
Check inrush as a separate item
Motor starting current reaches three to seven times rating. Either the PCS carries defined short-term overload or you add soft starters and variable-speed drives; otherwise the converter has to be sized for the peak and costs climb.
Write down the start/stop rules
Start the genset at a low SOC threshold, stop it at an upper one, and enforce minimum run time and minimum loading to avoid short cycling and wet stacking.
Classify loads and practise shedding
Split the load into critical, important and sheddable. When SOC bottoms out or a unit trips, the EMS sheds upwards from the bottom so communications, lighting and medical loads survive.
Do not compromise on environment
Coastal sites need salt-mist protection and heavy-duty corrosion class; plateau sites need altitude derating; desert sites dust-proofing and thermal management; cold sites a heated and insulated battery enclosure.
4. Three lines for a first estimate
Two classic mistakes — sizing from annual yield only, which leaves you short in winter; and saving money on converter overload capability. Both surface during the first year of operation.
5. Configuration reference
| Site type | Daily consumption | PCS power | Storage capacity | PV array |
|---|---|---|---|---|
| Telecom / repeater | 30–120 kWh | 10–30 kW | 60–200 kWh | 20–60 kWp |
| Farm / ranch | 200–600 kWh | 50–125 kW | 300–800 kWh | 150–400 kWp |
| Village / community | 1–3 MWh | 300 kW–1 MW | 2–6 MWh | 800 kWp–3 MWp |
| Mining camp / oilfield | 5–20 MWh | 1–5 MW | 4–20 MWh | 3–12 MWp |
6. A working equipment set
Four platforms cover most off-grid designs: the main unit establishes the AC bus and performs transfer, MPPT harvests each string, DC/DC integrates different battery voltages, and the wall-mounted unit serves small outdoor sites.
All-in-one hybrid inverter
- IntegrationPCS + MPPT + EMS + transfer + distribution
- Battery side680–950 V, max 600/800 A
- PV input120 kW × 3 / × 4
- EnclosureIP54, plug-and-play
PV MPPT controller (buck-boost)
- Rated power200 kW / 150 kW
- MPPT range200–900 V
- Peak efficiency99.26%
- MountingIP65 wall-mount
Bidirectional DC/DC controller
- Rated power210 kW
- Voltage range200–950 V
- Peak efficiency99.2%
- FeatureBidirectional buck-boost, parallelable
Wall-mounted storage converter
- ProtectionIP65
- MountingWall-mounted
- InputDual AC input with ATS
- FeatureInternal transfer plus genset hybrid operation
7. Delivery sequence
Data collection
Load list, daily curve, coordinates and climate data, existing genset model and fuel records.
First sizing
Two or three power/capacity options with capex and fuel saving compared.
Simulation check
Hour-by-hour SOC, curtailment, genset hours and autonomy verification.
Engineering and quotation
Single-line diagram, layout, earthing and surge protection, supply list and lead time.
Build and FAT
Cabinet manufacture, full integration test, load and transfer tests, burn-in.
Commissioning and training
Installation guidance, SAT retest, O&M training and spare parts handover.
8. Sites in service
9. Frequently asked
Can we drop the genset entirely?
Technically yes, but covering the worst seven to ten consecutive days demands very large storage and PV. Most projects keep one genset as insurance and push its annual running hours down to a few hundred.
Will cloud cover cause sudden blackouts?
Not with SOC-linked genset start. The EMS starts the engine before SOC reaches the floor and sheds non-critical load first if the deficit persists.
How is maintenance handled remotely?
The system reports telemetry so cell imbalance, fan faults and similar issues surface early. We also hand over a wear-parts list and train local staff, keeping on-site interventions short.
Can we keep our existing genset?
Usually yes. We adapt its interface and control so it runs only inside its efficient loading band — which is exactly what a diesel-storage hybrid is for.
Tell us where the site is and what it needs
Send the daily load curve, longest acceptable outage and existing genset details — we return a configuration validated against your worst month.
Request an off-grid proposalNo products in this category yet — product series are being published. Enquire for the full range.