Solar guides
Plain answers to the questions we hear on every site visit, with the numbers worked out.
All guides
- Grid-tie, hybrid or off-grid solar?Choose grid-tie if you want the lowest cost and rarely have brownouts. Choose hybrid if you want lower bills and power during brownouts, because it adds a battery. Choose off-grid only where there is no grid connection, such as farms, resorts and remote sites.
- How net metering worksNet metering lets homes and businesses with solar systems up to 100 kW export unused power to the grid. Your distribution utility credits each exported kWh at its blended generation cost and deducts it from your bill. In Zambales and Pangasinan you apply with your own utility or electric cooperative.
- Size solar from your billDivide your monthly bill by your rate per kWh to get monthly kWh. Divide by 30 for daily kWh, then by 3.6 (4.5 sun hours × 80% efficiency) to get kWp. A ₱5,000 bill at ₱12/kWh needs about 3.9 kWp, or seven 630 W panels.
- Battery backup in brownoutsA solar battery powers your chosen circuits when the grid goes down. Backup hours equal the battery’s usable kWh divided by the load in kW. A 16 kWh LiFePO4 battery, about 14 kWh usable, runs a 0.5 kW load of lights, fans, ref and Wi-Fi for about 28 hours.