Solar savings & payback calculator

Rooftop solar in Bangladesh generally connects under a net metering arrangement regulated by BERC and implemented by the local distribution utility — DESCO, DPDC, NESCO, BPDB, WZPDCL or a BREB palli bidyut samity depending on your address. Under net metering, a bidirectional meter records both the power you draw from the grid and the surplus power your panels export back to it during sunny hours when your own consumption is lower than generation. At the end of each billing cycle, the utility nets the two figures against each other; if you exported more than you imported, the credit typically carries forward rather than being paid out in cash, and any unused annual credit is usually settled at a wholesale-linked rate rather than the full retail rate. Approval requires an application to your utility along with your sanctioned load details, since the size of the solar system you can install is generally capped relative to your existing sanctioned load rather than being unlimited.

The economics work best for households or businesses with substantial daytime consumption — offices, shops, workshops and homes with someone present through the day — because self-consumed solar units displace a full retail-rate unit, while exported units are usually credited at a lower effective rate. A system sized to cover daytime baseline load rather than the entire monthly bill typically delivers a faster payback than an oversized system leaning heavily on grid export. Panel degradation, inverter replacement around year 10–12, and periodic cleaning are the main costs a full financial model should include beyond the numbers this calculator provides.