Storage facts series (II) | Large-scale batteries significantly reduce GermanCO2 emissions. How high the savings actually are depends on the assumptions and calculation method.
If you want to calculate the effect of large-scale battery storage systems on the climate, you have to deal intensively with technical details, make numerous assumptions and take complex interactions into account. Numerous adjustments can therefore be made to make the balance look good or bad – depending on the motivation.
One thing is clear: Battery Energy Storage Systems (BESS) allow the potential of renewable energies to be exploited far more effectively. They therefore significantly reduce the need for fossil fuels and can, for example, replace some of the planned reserve gas-fired power plants.
According to a study commissioned by us from the Fraunhofer Institute for Solar Energy Systems (ISE), a large-scale battery storage system with a capacity of two gigawatt hours (Gwh) saves up to 60,000 tons of carbon dioxide per year. This results in a total saving of up to 3.2 million tons per year or almost 20 million tons by 2035 (see below).
New parameters, significantly higherCO2 savings
By comparison, Germany’s entire electricity production currently generates 177 million tons of CO2 per year. Large-scale battery storage systems therefore have a significant climate-friendly effect – even in scenarios with rather cautious assumptions.
In consultation with Prof. Christof Wittwer, Head of System Integration at Fraunhofer ISE and member of our Scientific Advisory Board, we have calculated a further scenario, assuming, among other things, that large-scale batteries
- store an annual average of 70 percent green electricity between 11 a.m. and 3 p.m. and
- displace fossil power plant energy, which would otherwise have caused 400 grams ofCO2 per kilowatt hour.
Based on these assumptions, a large-scale battery storage system with a capacity of two Gwh can save the climate around 400,000 tons of carbon dioxide per year – and not “only” up to 60,000 tons. As is so often the case, the truth may lie somewhere in between.
One thing is certain: every large battery is good for the climate and future generations.
Here is the cautious forecast:
