Electricity Storage as an Opportunity for Renewable Energies

Stress on the climate and environment, finite resources, and the constant risk of supply bottlenecks: fossil fuels have a whole host of disadvantages. Nevertheless, a large part of the electricity in this country still comes from coal, oil, and natural gas. The switch to renewable energies is a declared goal of the federal government, but progress is slow.

Too slow for some. And so private people, businesses, and municipalities are slowly bearing their power supply into their own hands. Photovoltaic systems (also called solar generators or simply PV systems) are an excellent way to ensure your power supply in a climate-friendly and sustainable manner.

Maybe you are thinking about getting a PV system or you already own such a system. Then you might be wondering: what to do with excess energy and where can I get electricity from when the sun isn't shining? Solar power storage is the answer to these questions. What technology is behind it, what you should consider when buying and installing and how you can use subsidies for your electricity storage?

What is electricity storage?

The sun is pure energy and in all probability, its fuel will last for a few billion years. So it is merely logical to utilize this energy here on the globe. Photovoltaic systems are a well-known possibility. These convert the radiation emitted by the sun into electricity using solar panels. Because the systems are available in every dimension, they are suitable for private households as well as for large projects.

Photovoltaics supplies energy unevenly

Despite everything, PV systems have a small "dark side": Depending on the weather, time of day, and season, different amounts of solar radiation reach the system. As a result, more energy than required may be available on sunny days. At night or when the sky is gray, however, electricity production falls below the demand limit.

In both possibilities, there is the chance of utilizing the public power grid. On the one hand, you can feed your additional electrical energy into the general grid for a fee. On the other hand, you can use the main supply and buy additional electricity if necessary. However, these solutions are not efficient either from a financial or ecological point of view.

Solar storage ensures the balance

If you want to make your power supply as sustainable and self-determined as possible, a solar power storage system can help. As the name suggests, this device stores the (excess) electricity from your photovoltaic system. The electrical energy is then available at any time and you can call it up when you need it. The public grid only comes into play again when your electricity storage is full or empty. If it is full, the excess electricity flows into the public grid; if it is empty, you have to draw electricity from the grid.

In this way, you can produce your power supply independently to an enormous extent. The size of your photovoltaic system, the charging capacity of your electricity storage, and your electricity consumption determine how independent you are from the public grid.

Store energy for short and long periods

At the same time, you can relieve the public grid with some electricity storage devices: Power storage devices provide a so-called balancing power and help to guarantee the stability of the grid frequency.

Together with shift storage - these are mainly used for seasonal energy storage - power storage belongs to the type of short-term storage. These are marine batteries, either lead or ion lithium-based (more on that later). Their energy storage is not designed for long periods. Rather, they only store the electrical energy for a few seconds, minutes, or at most hours. You can't accumulate a "stock" of solar energy this way, but you can very effectively bridge days with little sun and night.

The long-term storage of large amounts of energy is comparatively difficult. There are even long-term storage approaches that merely drive via a few processes a year. However, these are usually complex power-to-gas plants (here, to put it simply, energy is stored in hydrogen or methane) and large water storage power plants - no solutions that can be considered for private households. Of course, you can also buy a 12v lithium battery to store electricity.

Electricity storage systems are more popular in the US than ever before

Storage technology is constantly evolving. This is important. Because the long-term storage of energy from renewable sources is still one of the major challenges and barriers to the energy transition. This is formulated in the climate targets of the federal government. The Federal Government has changed the Climate Protection Act and tightened the climate protection requirements. The modification to the rule came into strength on August 31, 2021. The goal of greenhouse gas neutrality is now enshrined by 2045. By 2030, emissions are to be reduced by 65 percent compared to 1990 levels.

Good prospects for photovoltaics

But are these goals realistic and achievable? Basically yes. And this is even though the share of renewable energies in gross electricity consumption fell for the first time since 1997 in 2021: from 45.2 percent to 41.1 percent. Responsible for this clear downward movement was the unfavorable weather conditions - wind turbines supplied significantly less electricity - and the demand for electricity, which has been increasing again since the corona pandemic.

Photovoltaics was able to compensate for the lack of sunshine through high expansion in 2020 and 2021 and even achieved a slight increase of almost 1 percent. In 2021, the photovoltaic solar panel system generated 50 billion kilowatt hours of electricity. In the US, the installed photovoltaic capacity in 2021 was 59 gigawatts. Photovoltaics has thus overtaken wind power. The total installed capacity here is 56.3 gigawatts.

Great prospect for solar storage

According to the US Solar Industry Association e. V., 413,000 solar power storage units were installed in the US in 2021. There are currently 2.2 million installed photovoltaic systems. For comparison: in 2013 there were just 5,000. At the moment all signs point to the fact that this trend could continue in the coming years.

The Federal Government has also recognized that energy storage systems play a key role in the switch to regenerative sources. And so since 2012, it has been supporting countless projects on the subject as part of the "Energy Storage Funding Initiative". With a total funding volume of 200 million dollars, you can still hope for one or the other innovation.