Almost all the households of the country face problem of electricity-cuts or load shedding. A conventional way solving this is using Invertors with battery back-up. However, a non-conventional and upcoming method has been using Solar Energy. The equipment required for a basic Manually-Operated Solar Back-up system are:
- Solar Panels
- Solar Charge Controller
- Battery pack
- DC to AC Inverter
- Wiring & Sockets
- Panel Stand
- Battery Rack
Now, we look at functions of each of the following equipments:
| Equipment | Function |
| Solar Panel | Generate DC when Sunlight falls on them |
| Solar Charge Controller | Charges battery and prevents reverse current in case of voltage drop. |
| Battery | Stores Electricity DC current (as chemical energy) |
| DC to AC Inverter | Converts DC current from batteries to AC Current |
| Panel Stand | Mounts Solar Panel safely |
| Battery Rack | Keeps battery safe |
The 3rd step is the connection diagram:
With Equipment and arrangement being clear, the next step is estimation of House load and based upon that System capacity. For sake of comparison, let us make a list of equipments that are to be placed on Inverter back-up in a 3BHK flat.
| Equipment | Number | Watts | Total |
| Tube Lights | 3 | 40 | 120 |
| Fans | 3 | 80 | 240 |
| Refrigerator | 1 | 100 | 100 |
| Computer | 1 | 120 | 120 |
| Misc. | 1 | 70 | 70 |
| Total | 650 |
Hence, the load of equipment in our case = 650 watts.
Lets say we need backup for 1 hr.
Now going in reverse order:
- Capacity of DC-AC Inverter = 650/0.8 (safety factor) = 800watt
- Battery Capacity = power to be delivered * time = 650* 1
- Considering each battery = 12 V & number of battery = 2
- 650 = 2*12*AH
- AH = 650/48 = 27
- Hence, we need to buy 2 batteries of 12 V and 27AH each
- Solar panel, needs to produce 650 watts of power on average in a day (5 hrs,0.8 efficiency factor) .
- Panel wattage = 650/ (5*.8) = 162.5 watt
- Thus 200 watt solar panel that produces dc electricity at 12V, would suffice.
This brings us to last and most important part. i.e. cost of the system
| Equipment | Cost Per unit | Total Cost |
| Solar Panel | 6000/100 Watt | 12000 |
| Solar Panel Stands | 5000 | 5000 |
| Solar Charge Controller | 3500 | 3500 |
| Solar Invertor | 3000 | 3000 |
| Batteries | 5000/unit | 10000 |
| Wiring | 2000 | 2000 |
| Total System Cost | 35500 |
Thus complete system would cost 35000 INR