ES-Micro is the cheapest solution. It is very easy and safe to install because it operates at low voltages on panel side and on battery side. In some cases you will not even need an electrician.
The ES-Micro models tolerate varying sunlight conditions because the inverters optimise the use of each panel individually. They can live with a mixture of old (used) panels and brand new panels. You can add a battery, typically a modern Lithium 48V battery. However, if you have access to used batteries with older technology it may even be possible to use them. The overall energy storage efficiency is around 77% – which is not perfect but acceptable in many cases.
The ES-Micro family is designed for a range of 2-16kWp. By default it feeds all its energy into your building and any surplus will go into the grid. Grid feeding can be delimited if this is required by legal restrictions or by your grid provider’s rules.
In combination with a battery the ES-Micro family will provide energy from the battery during off-grid periods. Even more, some of its panels will be able to produce soar energy in such periods.
Your ES-Micro devices will come preconfigured so that they work out of the box. If you do not object, we will occasionally have a look at the production data of your system. With your permisssion we would also like to publish your production data in anonymized form on our website. In case we see any problems or if firmware updates are necessary we may be able to help you. Of course you have admin access to your system and can monitor all data via browser or via an app on your mobile device.
This product family is designed for 6-15 kWp. The installation is more challenging and you have to deal with high voltages because panels are connected in series and the battery also operates at a high voltage. It requires a professional electrician at least for the installation of energy meters and fuses, for final inspection and grid connection.
All panels should have free access to sunlight. You can have two groups of panels (“strings”) facing into different directions.
The overall system efficiency including energy storage is around 95%. This product family always comes with a modern battery. You can integrate used panels if they are all of the same type. Energy feeding into the grid can be controlled. Off-grid functionality is an integral part of the ES-Hybrid family.
Your ES-Hybrid devices will come preconfigured so that they work out of the box. If you do not object, we will occasionally have a look at the production data of your system. With your permisssion we would also like to publish your production data in anonymized form on our website. In case we see any problems or if firmware updates are necessary we may be able to help you. Of course you have admin access to your system and can monitor all data via browser or via an app on your mobile device.
When to take an ES-Hybrid system
The smallest ES_Hybrid system is ES-Hybrid-6-7.6. It has 15 new panels or ~ 20 older panels. Your yearly energy demand should be above 5.000 kWh. You or the electrician wll have to make changes in your fuse box. You must act carefully when connecting the panels to strings on the roof. Your investment will be ~ 5.000€
The largest system is an ES-Hybrid-14.4-25.6 which uses 32 panels.
If your demand is significantly higher, say 30.000 kWh per year and if a large amount of energy is needed during night time (like in a hospital), you could install two or more of these systems. The inverters can operate in a master/slave configuration of up to 8 devices.
When to take an ES-Micro system
If you do not have much money, go for an ES-Micro system. You can start with used panels and a small system of 5kWp without battery. Check if you can find a donated battery which is compatible with ES-Micro. Mounting work will be safe due to low voltages. Your system can be extended later by simply adding more panels and more inverters. The added panels can have different type.
If you start with a battery your investment into the battery inverter will not be lost if you add a larger battery and more panels later. If you want to protect yourself against grid failure it may be good to take a system with 4 micro inverters and a battery. One or two of the inverters should be connected to the EMS socket of the battery inverter so that they will also work during off-gid periods.
Try to get permission from your grid provider that you can feed surplus energy into the grid without being paid. Tell him that your system will never feed energy into the grid while the grid is down. This could be an important point in the discussion with him.
An ES-Micro-4-5 system will require an investment of ~ 2.400-4.000€
Cost Comparison for a system of 6kWp and 5..7.2 kWh battery