Independence Calculator

More and more photovoltaic system owners are choosing to invest in a battery to complement their independent energy production strategy. Every second SOLARWATT PV installation is coupled with a MyReserve battery!

Do you also want to raise your energy independence from utility companies and rising electricity prices – while also doing something good for the environment? With MyReserve you can do both. Our solar battery enables you to use much more of your own self-produced, clean solar energy – even at hours without sun!

The following questions will help you finding the optimal battery size for your own needs:

  • How independent do I want to be from expensive grid power?
  • How large is (or should be) my rooftop photovoltaic plant?
  • What should the capacity of my battery be to find the best ecobalance?


This independence calculator was created by the HTW Berlin to help you determine the potential degree of self-sufficiency and your possible share of solar power consumption when paired with a solar battery. With this tool you will find the ideal battery size for your individual needs. Do you have any questions? We would be happy to answer them here.

Overview of the terms used:

Annual electricity consumption:
The annual electricity consumption is your current average electricity requirement per year. Photovoltaic systems are often operated for more than 30 years so a possible increase of your annual power requirement should be planned. New purchases such as an electric car or pool can noticeably increase your home’s power demand.

Photovoltaic output:
The photovoltaic output corresponds to the maximum solar energy that can be generated. The plant capacity is limited by the available roof area and the performance of the solar panels.

Usable battery capacity:
The usable battery capacity is the amount of power that the battery can store. You have to charge your battery for storage and discharge it for consumption.

Share of private consumption:
The share of private consumption is how much of the solar power from your roof is actually used in your own home. With a battery, you can use significantly more of your own privately-produced electricity yourself.

Degree of independence:

The degree of independence shows self-sufficiency from expensive grid electricity. The value shows how much of your annual power needs can be covered by your own environmentally friendly solar energy.

Direct consumption:
Direct consumption is the portion of solar power which is immediately used within the household as it’s being generated.

Grid feed-in:
Solar current that is neither used within the household nor stored in the battery for later use is fed into the public power grid. In some countries you receive a feed-in tariff as payment for this current, but it is almost always less than you have to pay for your own grid power consumption.

Consumption from the grid:
Grid consumption is how much electricity you have to purchase from the public grid.