A grid-tied system is the least expensive option for most people who want to install a solar panel system on their home. With a net metering program, you can sell electricity to the utility company for an agreed-upon rate. Most grid-connected systems are 85% efficient or better. The inefficiencies are caused by heat loss and power loss through the conduction of the cable.
An off-grid system is your other option. These systems are less efficient by about 55%. They are more expensive because you need to build a battery bank to store the electricity, whereas in a grid-connected system you draw electricity from your grid when power runs out. When you add batteries, you lose about 25% of your system’s efficiency.
Hybrid systems are an attractive option because they provide you with backup power using batteries in the event of a blackout. Most people opt for a grid-connected system because it requires less maintenance, is close to 99% efficient, and doesn’t need water or battery replacement. Some people use a small inverter generator for backup power in this system.
Be sure to reduce your energy usage and get an accurate idea of your total kWh needs per month before installing a system. Energy star appliances and HVAC are very helpful. It is also much more cost effective in the long run than installing a solar panel system. Among the energy efficiency measures you want to take, be sure to weather-strip, insulate, and install double-glazed windows.
When you do your kWh calculations, the hours between 10 am and 2 pm give you the most power.