Load-based PV engineering
About us
We size photovoltaic systems from site load and climate — not from a generic kilowatt guess. Typical demand sets daily energy, peak demand sets MPPT or hybrid-inverter power, and local irradiance plus high-temperature voltage windows set the array. Storage is added only when you ask for backup hours. You receive a BOM, an indicative FOB China cost, scheme drawings, and a design report.
How a scheme is sized
The same four steps a field engineer uses — encoded so a first pass can be run online.
Load, not nameplate
Typical kW drives energy and storage hours. Peak kW plus a margin sizes the hybrid inverter or the MPPT. The two figures are never swapped.
Climate and voltage
City weather sets irradiance, cell temperature, Voc at cold start and Vmp at hot noon. Strings must stay inside the MPPT window after soiling and cable drop.
One architecture
Home rooftop: AC loads, hybrid inverter, zero export, grid import only. Site energy: DC loads and MPPT only — no inverter and no grid feed-in path.
Deliverables
Sized array, controller or inverter, optional battery, cable notes, grounding notes, drawings, and a construction guide. Online files are watermarked previews.
Capabilities
Engineering that can be checked — load, voltage, loss, and paper — not a brochure kilowatt.
Where we work
Led by Richard LI. The practice is built for high-temperature, dusty, weak-grid or off-grid sites: rooftops, workshops, and DC industrial loads across Arabic-speaking Middle East and North Africa.
- Zero-export homes that still import from the grid when the array is dark.
- Site DC plants that never introduce an inverter or a grid-export path.
- Hot-roof string windows that stay legal at 70 °C cell temperature and dusty soiling.
Representative design cases
Typical schemes we size. Figures are class values from the same load-based method as the online tool — not a claim of a named client’s commissioned plant.
Home · rooftop AC
Residential rooftop — hybrid, zero export
Household AC loads on a hybrid inverter. The array covers daytime use; the grid supplies night import only. Storage is optional if the owner wants hours of backup.
- ~8 kWp class
- Anti-export · grid import only
Site · DC energy
Industrial yard — MPPT only
Ground-mount array feeding DC process loads through MPPT controllers. No hybrid inverter, no AC coupling, and no route back to the utility.
- Peak-load MPPT
- No inverter · no export
Climate · thermal
High-temperature rooftop — voltage window
String length cut so hot Vmp stays above MPPT minimum and cold Voc stays below equipment maximum. Soiling and cable drop are taken off before the check passes.
- Voc / Vmp derating
- Soiling + thermal loss
Storage · backup
Clinic / workshop — optional BESS
When backup hours are specified, usable battery energy is typical load × hours, with depth-of-discharge and inverter/MPPT limits applied. Unchecked storage stays at zero kWh.
- Hours × typical kW
- No silent battery
Equipment brands we size against
Module and inverter / MPPT families available in the online selector. Final procurement can follow the same FOB China lines or a brand you name in the brief.
- Jinko
- Longi
- GCL
- Sungrow
- Huawei
- Solis
- Deye
- Dunext
Standards and honesty
Checks follow IEC-oriented practice and hot, dusty MENA site conditions (irradiance, temperature, soiling). Online output is an indicative scheme: useful for sizing and bidding, not a stamped construction-permit set. Yield uses pvlib climate data; economics are FOB China unit prices, not installed EPC.