Most people believe that home inverters are very economical. They are a good source of getting power during power shutdowns. People have the notion that the cost of getting power from the home inverter is the same or almost the same as the electricity provided by the power grid.
But, this is not True.
For each unit of power supplied by the home inverter you roughly pay 1.6 times the grid rate.
For eg., if the grid tariff rate is Rs. 6.5, then the cost of the electricity produced by the home inverter will cost you roughly Rs. 10.4. (Rs. 6.5 x 1.6). This is due to various kinds of loss associated with the use of the Home inverter.
The larger the home inverter size, larger will be the electricity produced. The larger the electricity produced, the higher will be the expenditure per month from the use of the home inverter.
Since, this expenditure is a recurring monthly expenditure, over a period of time the loss becomes substantial.
To compare the home inverter with a PV solar system, let’s take the expenditure incurred by running the home inverter over a period of 25 years (the life of PV solar systems).
We have made a table below showing the cash outflow per year on the use of a home inverter. Please note that we have ignored the cost of the batteries as it will be required in both the PV solar system and the home inverter system and hence is of no significance here. The assumptions made to calculate the figure has been mentioned in the table below.
| Home Inverter: How much you pay for it | |||
| Assumptions | |||
| Power Shutdown/Day | 3 | Hrs | |
| Energy Charges | 6.5 | Rs./ Unit | |
| Elect charges escalation/yr | 3% | P.a. | |
| Effective Energy Rate approx (assuming 60% loss | 10.4 | Rs./ Unit | |
| Inverter Output | 1 | Unit/Hr. | |
| Years | Inverter Run Hrs. | Annual Increase Factor | Electricity Consumed/Annum(Rs.), Outflow |
| 1 | 1,095 | 1.00 | -11388 |
| 2 | 1,095 | 1.03 | -11730 |
| 3 | 1,095 | 1.06 | -12092 |
| 4 | 1,095 | 1.10 | -12477 |
| 5 | 1,095 | 1.13 | -12887 |
| 6 | 1,095 | 1.17 | -13325 |
| 7 | 1,095 | 1.21 | -13793 |
| 8 | 1,095 | 1.26 | -14294 |
| 9 | 1,095 | 1.30 | -14832 |
| 10 | 1,095 | 1.35 | -15412 |
| 11 | 1,095 | 1.41 | -16037 |
| 12 | 1,095 | 1.47 | -16715 |
| 13 | 1,095 | 1.53 | -17451 |
| 14 | 1,095 | 1.60 | -18253 |
| 15 | 1,095 | 1.68 | -19131 |
| 16 | 1,095 | 1.76 | -20095 |
| 17 | 1,095 | 1.86 | -21159 |
| 18 | 1,095 | 1.96 | -22338 |
| 19 | 1,095 | 2.08 | -23653 |
| 20 | 1,095 | 2.21 | -25126 |
| 21 | 1,095 | 2.35 | -26789 |
| 22 | 1,095 | 2.52 | -28680 |
| 23 | 1,095 | 2.71 | -30847 |
| 24 | 1,095 | 2.93 | -33354 |
| 25 | 1,095 | 3.19 | -36284 |
| Total Run Hours | 27,375 | Total Outflow | -488,142 |
Figures Marked in ‘-‘ are Cash Outflow/year
