How can you optimize solar modules

Optimize self-consumption

Energy self-sufficiency: Make yourself more independent from the mains power

What does energy self-sufficiency mean?

The term energy self-sufficiency describes concepts in which energy consumers use locally available energy carriers and sources and are therefore not dependent on external energy supplies. In connection with an end consumer, the term (and similar terms such as energy autonomy and energy independence) is usually used in the form that the user makes himself independent of the energy supplier and covers his own energy needs. Since this is usually not 100% possible, one speaks of a degree of self-sufficiency.

Do you want to calculate how energy self-sufficient your PV system can be? Then use our independence calculator.

This is how you can increase your energy self-sufficiency with the SOLARWATT photovoltaic system:

High self-consumption - how does it work?

It is a fundamental problem that the generation of solar power does not match our daily rhythm. During the day, most people are at school or at work and little energy is used. During this time the sun shines and the PV system generates a lot of electricity. In the morning and in the evening, when we make coffee, shower, watch TV or sit in the room with electric light, i.e. when our own consumption is particularly high, little or no solar power is generated. For a long time there was no alternative to feeding surplus electricity into the public grid and buying expensive grid electricity when needed.

Intelligent control of energy consumption

One solution to the dilemma is intelligent control of self-consumption with an energy management system. This switches on electricity consumers precisely when a particularly large amount of electricity is being produced. So the dishwasher or the pool pump can run even when nobody is in the house. The devices are z. B. operated via switchable radio sockets. However, there are narrow limits to this method of optimizing self-consumption. Not all conventional household appliances can be switched on and off in this way, and not all activities that use electricity can be postponed. The increasing networking of building technology and devices in the smart home will, however, open up further possibilities for energy management in the home in the future. Self-consumption can also be increased further by integrating and controlling additional consumers such as heat pumps or electric vehicles.

Add electricity storage to photovoltaic systems - increase self-consumption

Rechargeable batteries or "accumulators" are already in use in many areas, for example in smartphones. So the idea of ​​storing electricity is not new. However, the much larger and more powerful household electricity storage systems have long been very expensive and ineffective.

Meanwhile, however, development has advanced and home storage has become powerful and affordable. If they are charged with inexpensive solar power, they save the purchase of expensive grid power.

Combination with the energy management system is recommended so that the storage systems work optimally. The electricity storage system is always charged when electricity is generated and not consumed. Electricity that is not loaded into the storage tank can still be fed into the grid. The feed-in tariff is then an additional bonus for the operator of the photovoltaic system.

In the hours without sun, the operator of the system can use self-generated electricity until the storage tank is empty. Only then is mains electricity drawn again. Depending on the size of the electricity storage system, self-consumption can be increased and thus also the degree of self-sufficiency, i.e. H. independence from the energy supplier. With a storage tank, degrees of self-sufficiency of 80 to 90 percent are possible.

More independence from the mains electricity pays off

The feed-in tariff set out in the Renewable Energy Sources Act (EEG) has long been considered the main financial incentive for investing in photovoltaics. Nowadays it is hardly imaginable, but in 2004 feeding one kilowatt hour (kWh) into the public grid was remunerated with 54.7 cents! In the following years, the flat rate fell significantly, in 2019 10 cents per kWh was achieved. That is why the question arises again and again whether it is still worth buying a photovoltaic system. A question that can be answered with a clear yes, albeit for different reasons than in 2004.

Change of strategy in photovoltaics: self-consumption instead of yield

The high photovoltaic feed-in tariff from the early days had a clear political concern: the financial incentive was intended to motivate companies and households to invest in the generation of solar-generated electricity. At that time, the prices for a solar system were many times higher and the performance was significantly lower than with modern systems. The feed-in tariff laid down in the Renewable Energy Sources Act (EEG) was therefore decisive for the question of whether the investment is worthwhile.

Over the years, however, the situation has changed fundamentally: Solar systems have become cheaper and the feed-in tariff is well below the price of grid electricity. While a fed-in kilowatt hour brings the operator of a PV system around 10 cents, he pays 30 cents and more for one hour of mains electricity. The production costs, i.e. the costs for generating one kWh of solar power, are around 10 cents. You don't have to be a mathematician to understand: It's worth using the electricity you generate yourself! The order of the day is therefore to increase self-consumption and to optimize self-consumption!