Self-consumption is the amount of electricity that is immediately consumed when solar panels produce electricity.

The degree of self-consumption depends on, among other things:

• The consumption pattern of a home or commercial building
  • For example, a commercial building usually uses more electricity on working days than a residential house. At the weekend, when the company is closed, consumption will be less or even nil.
• The number of solar panels
  • The smaller the number of solar panels, the greater the self-consumption. Due to the netting arrangements, the consumption of solar panels for small consumers is often calculated in relation to a year's maximum consumption. If the starting point is direct consumption, it may be more favorable to have fewer panels.
• Season
  • When it is sunny and cold, solar panels produce relatively the most electricity. The production peak is in the summer. In the summer, much more electricity is produced than consumed.

Self-consumption on an annual basis

The direct consumption of solar panels in homes is between 10% and 30% of the annual electricity produced, depending on the number of phases of the connection. This percentage is higher for companies, up to about 50%. Self-consumption is therefore relatively low, which explains the increasing number of problems with the grid. Because all solar panels produce electricity at the same time and consumption is limited, production peak arises that the grid is not always able to cope with.

Optimizing the use of solar power

There are several options for optimizing the use of solar power.

• Design
  • To generate the highest yield, solar panels used to be installed facing south. But we now know that this results in a production peak that is less desirable. Orienting solar panels east-west results in a yield that is more in line with consumption. The yield per year is therefore lower, but the distribution is more favorable.
  • The choice of inverter can also have a favorable effect on the generation pattern. A somewhat smaller inverter can sometimes be beneficial.
• Curtailing
  • The production of a solar installation can decline if the grid cannot cope with it. This is called curtailing or topping. It means a small percentage of solar power is thrown away during the production peak. Curtailing can thus free up space on the power grid.
• Demand response
  • Demand response means that we can activate devices when there is a lot of solar power. For example, a boiler or an electric car can be charged when there is a high production. This is of course not possible with all devices or does not always make sense. The washing machine is often cited as an example, but the consumption of a modern washing machine is so low that its use only makes a very limited contribution to reducing the peak in solar power.
• Storage
  • Storage of solar power in batteries is an attractive way to reduce the peak. In Germany and Belgium, the demand for batteries for the storage of solar power has increased significantly. The Netherlands is still lagging behind due to the netting scheme and the lack of a network incentive. Considering the falling prices of batteries and the imminent adjustment of netting, it is expected that more batteries will also be installed in the Netherlands.
  • Less well known is storage via a boiler. In the event of overproduction, a boiler is heated, the hot water can be used later. This is a relatively cheap way of storage.