Self-Consumption

What Is Self-Consumption?

As regards excess energy, there are two situations for those who use a solar-panel based inverter system. They are

1. The excess solar energy produced is channeled back into the grid. In this case, no energy is stored by the user for use at another time. Any power needed for loads, above what is being produced from panels, is drawn from the utility.

2. In the second scenario, some of the solar energy produced is stored for use at another time when solar production is less than the loads. This storage is always in batteries.

The first situation means that users can sell their excess energy to electricity distribution companies. Otherwise called 'spot marketing' in other countries, we know that this is hardly a possibility in Nigeria. Other ways to manage this excess include

• To set up timers.

• To channel the excess to water heaters or any high-capacity appliances. There are inverters that are built to do this.

• To set up energy management systems.

• For most users, the best and only choice is to maximize self-consumption, by installing batteries alongside solar panels. This explains why batteries are a staple component of inverter systems in Nigeria.

An graph showing how home energy consumption and solar production from a 3kW solar system intersect during the day. The red area above the blue line represents exported solar energy. IMAGE from Solar Choice

Why Self-Consumption Makes Sense

Self-consumption makes sense for financial reasons. Since solar panels do not work at night, to have a storage system means eliminating the need for power bills and nighttime generators.

Self-consumption is achieved by the use of hybrid inverters alongside batteries. A hybrid inverter can increase self-consumption from 30% to more than 70%. To be able to achieve that, a hybrid inverter will simultaneously manage inputs from both solar panels and a battery bank, then charge the batteries with either solar panels or the electricity grid, depending on availability, consumption or preference for use at a later time, mostly nighttime.

Depending on preference, a hybrid inverter which is set to prefer solar energy, (the preference can be manually set in some inverters, otherwise most hybrid inverters are built to prefer solar) will first use the solar power, and if the demand exceeds the solar power, it will import power from grid. If the solar power exceeds the power demand, the excess power is used to charge batteries and store the electricity for later use.

Self-consumption totally eliminates the necessity of grid power or reduces it to a bare minimum. This explains why grid-tied inverters, that is inverters that are able to export excess power into the grid are marginalized in the local power systems industry. At SolarKobo, we encourage users to maximize self-consumption by acquiring a battery bank and using an off-grid hybrid inverter.