**5. Conclusions**

Self-consumption is developing more and more in the past years instead of the installations in the total resale. And for good reason, in addition to participating in the *What is the Profitability of a Photovoltaic Installation in France for an Individual? DOI: http://dx.doi.org/10.5772/intechopen.109859*

#### **Figure 27.**

*Comparison of the years from which the 9 kWp PV installation in self-consumption becomes beneficial according to different irradiances and self-consumption rates and based on the variables presented in Table 5.*

energy transition, a self-consumption installation is an interesting alternative for a monetary investment.

Indeed, currently with a buy-back price of electricity that is increasingly low for the total resale, self-consumption is in most cases more profitable for installations at home ranging from 1 to 9 kWp.

The benefits are more advantageous in the case where the irradiation is maximum on average over the year, 30 to 40° south, although the correlation consumption/ production is the worst.

Moreover, the calculations of profitability were made for 20 years because it is the time of the contract of repurchase of the electricity proposed by EDF. But at the end of this contract, nothing prohibits to renew it. The initial investment being already amortized and having no repurchase of material (life span of the panels higher than 30 years and that of the micro-inverters of 25 years), the profitability will be only better than that calculated here.

#### **Figure 28.**

*Comparison of the gains reported after the 20 years of the contract for a 9 kWp installation installed in self-consumption according to different irradiances and self-consumption rates and using the variables presented in Table 5.*

Also, the profitability in self-consumption can be improved by using an energy management. Indeed, if appliances are used at the most opportune moments, when there is a surplus, the rate of self-consumption, the quantity of energy produced that is directly consumed on site and not lost or resold at low cost, will only be better. If for example, the water heater, the washing machine and so on are launched at the time of the surplus to the link of evening, the rate of self-consumption will increase and consequently the profitability will improve.

Note that for each calculation of profitability in self-consumption, the calculations are entirely to be redone because each household has its own consumption habit.

Thus, it would be interesting to make profitability calculations for different load curves: household without electric heating (represents 80% of the houses), household of two persons, household of six persons, household of retired person and so on. The electrical energy can be divided or multiplied by 2 or 3, with different consumption habits. *What is the Profitability of a Photovoltaic Installation in France for an Individual? DOI: http://dx.doi.org/10.5772/intechopen.109859*

#### **Figure 29.**

*Comparison of the interest rates that an installation would earn after 20 years of the contract for a 9 kWp installation installed in self-consumption under different irradiances and self-consumption rates and based on the variables presented in Table 5.*

Finally, investing in photovoltaic seems to be interesting in all cases (total resale or self-consumption with sale of surplus). But to privilege the self-consumption seems to be the most judicious especially as the inflation of electricity has great chance to increase more quickly than in the past, having as a direct effect an increase in the profitability of an installation in self-consumption.
