Battery storage for home solar systems

Home battery storage system with battery for private use. The home battery prices are at a very low point especially the lithium ion with LiFePO4 technology. Solar storage options starts to be efficient and affordable.

Every solar power systems design these days and in the future, should have a oppertunity to implement energy storage. Backup power or off-grid, invest in a solar plus storage system is affordable for home and business. The return costs are mostly less then 10 years.

Battery storage for home solar systems

The importance of renewable energy is for every one clear. PV panels are sustainable. The sun, our unlimited energy source, ensures that your panels generate electricity in daylight. If they generate more energy than you need, it goes to the electricity grid. Saving more on electric bills is therefore interesting to use that energy more efficient.

The use is not harmful to the environment. You contribute to a better climate with photovoltaic panels on your roof. Of cours we are talking about LiFePO4 storage solutions and not about lead acid batteries. These types are not suitable for photovoltaic backup solutions. Even in electric vehicles you are do not find any anymore. ( joke from the author )

The price of fossil fuel has risen sharply in recent years, while the price for a PV system has fallen. A return of more than 20% is possible. Depending on the roof type and number of panels, they are recovered after 5 to 9 years. The modules have a lifespan of at least 25 years and the inverter 15 years.

Difference on-grid, off-grid and hybrid?

The on-grid system is by far the most used in Portugal Algarve. The surplus produced goes into the electricity grid mostly.

The current netting scheme in Portugal thas not ensures that those kilowatt-hours are checked out one-on-one. In case your installed solar panel energy system does not provide sufficient or no electricity.

With the current feed in tariffs its not interesting at all to feed the grid. Thats what making home battery storage solution so interesting. Store the surplus you generate, keep having clean energy!

That sounds logical. But due to the high energy tax,  70% of the KWh price, this is an indispensable arrangement for on-grid systems. Without net metering, individuals would receive 70% less for each KWh returned than they would pay for each KWh purchased.

The other extreme is an off-grid solar system

The system that most closely meets the romantic image of autonomous energy supply.

Disconnect the cable:

We all get it from our own roof. And we use the battery to smooth out the folds between use and production. In case there is no power grid, this is even the only solution.

But there are also considerable disadvantages. If your battery is empty, you no longer have any escape options. The RCT power inverter and the SMA sunny storage and sunny island have the option to install a gasoline or diesel generator. With auto start on the generator, you can program that it will start as the lithium ion batteries are on 20%.

On the other hand: if your battery is full, the precious power that you generate afterwards will be lost.

Hybrid system combines the advantages of both.

A battery to store photovoltaic power for later use. But also access to the network for moments when consumption is higher than what the battery can provide.

Or for the moments that the panels still supply power while the home battery is full. In that case, abundant KWhs can be supplied to the grid.

In combination with energy production management software, battery owners can further benefit from peak demand charges and off-peak rates. Such as purchasing and storing mains electricity during off-peak demand hours.

How do home batteries work?

The most important are the battery itself. The battery charger / inverter and the energy management software to make storage technology and energy consumption as efficient as possible.

Even without storage, every equipped photovoltaic system with an MPPT inverter that converts the direct DC coupled current into the AC alternating current. If you also want to be able to store electricity, you need an extra inverter in most cases.

All the above components are available in different combinations. For the consumer it is therefore very important that he knows exactly which components the product "home battery storage" contains. For example, the much-discussed RCT power has a battery that is supplied without an inverter to keep the costs low. This does not apply to hybrid systems from SMA.

Battery storage for home solar systems

Below the most important storage combinations that consumers can choose from.

    • Micro inverter:

      If a solar system installed with a micro inverter, thats somewhat hard to regulate. With a SMA sunny storage you have the abbilety to store the surplus into a BYD battery bank. Experts from solar2power have the solar energy storage solutions for you. They design installations on demand

    • All in one hybrid inverter:

      Don't you want to worry about anything? Various producers, such as the German companies RCT Power, offer an solar installation all-in-one package. A box contains a hybrid inverter for both panels and battery and built-in batteries. The storage capacity of those batteries varies.

    • The lighter versions can store energy around 3.5 KWh of power: just enough for a big load in the tumble dryer. The maximum capacity is around 11.5 KWh.
    • If you would like more safety:

      Then you can opt for two separate inverters. Or for a hybrid inverter / charger that works for both the panels and the batteries. Then select single batteries to attach to, such as SMA sunny storage or other brands that are available.

    • The individual batteries vary from 2.5KWh to 10KWh each. They can be stacked to your heart's content to increase the storage capacity.
    • This variant, therefore, offers more flexibility. If you use two separate inverters, its also more suitable for large solar PV systems with high intensive power consumption. It does require more installation work.
    • Energy Management:

      The energy management software, which comes with most storage systems, helps consumers to use generated electricity with maximum (financial) effect. For example, by having household operations that cost a lot of electricity. Such as washing and drying, take place automatically during the day. That is the moment when your panels generate the most power.

In this way you prevent your energy from falling short in the evening. And you may have to get expensive kilowatt hours from the grid.

You can also charge your solar batteries during the night. When the electricity price is the lowest - with electricity from the public grid. Many commercial solar companies use this kind off cost saving.

The software further helps you to map your energy consumption and adjust it where possible downwards. A last interesting possibility is to trade your electricity in your battery. If the demand for electricity is high and you can receive a good price, sell it. For example, SMA offers users the possibility with smart meters to control the stored power. For example with the with the SMA Home manager 2.0.