Powerwall for peak-shaving

Peak Shaving Powerwall

There is always time for a guided tour, when a client or friend visits MG Energy Systems in Leeuwarden. The reception, the office and the production hall are part of this tour, as well as the coffee machine. The coffee serves a warm welcome, although one specific wall always attracts more attention. A kind of ‘wall of fame’ but with another title: a wall of power! It is the energy storage system that powers the company needs.

Read along this interview with MG co-owner Gerard van der Schaar about the powerwall at MG Energy Systems.

When and how did the powerwall at MG come into existence?

“We have been making use of this powerwall since we moved to this building in 2017. It originated from a solar grid-connected project in Tanzania, the Lahia Tented Lodge in Serengeti. In order to get a better insight on their project requirements and challenges, an MG employee decided to build a prototype. This resulted in a satisfied project outcome ánd a powerwall for company use!”

Solar panels for peak shaving
MG Master LV in combined mode

What are the components of the MG powerwall?

“A general powerwall system includes solar panels, converters and a battery bank. More specific, our powerwall contains 48 batteries. There are 400 solar panels mounted on the roof. Between these both components, we have two kinds of converters. The solar panels generate direct current (DC) electricity. One kind of converter – the Solar MPPT –  transforms the solar power to collect the energy in the battery bank. The other converter converts the direct current (DC) to alternating current (AC). This is then suitable to feed directly into the grid.”

While still talking, Gerard walks enthusiastically towards a small device, hanging on eye-sight. Then he continues: “With this device, we can get a quick overview about the solar power generation of this moment. It even shows a monthly overview of the solar energy production from previous years.”

What makes the powerwall reliable?

“We collect and store the solar energy in the weekend, and use it during working days. In addition, the batteries are connected in three parallel strings, which operate in a combined mode. This combined mode is unique in the market and is called a redundant battery system. When one string of batteries happens to fail, then the two other batteries-strings still continue functioning.

Furthermore, in case the main grid would fail, we are still able to continue our work here at MG. Thanks to the powerwall.”

The three battery banks have a capacity of 80 kWh each. The total capacity is therefore 240 kWh.

The powerwall is running in a combined mode.

In this mode, the three parallel battery banks are configured as a redundant battery storage system.

Grid Connected ESS Powerwall

Does a powerwall need maintenance?

“No, not at all. The solar panels have a 25-years span of lifetime and the batteries will keep functioning up to 15 years. The only recommendation I can make, is cleaning the solar panels regularly. This will make sure that the energy production is most efficient during the whole season!”

For whom is it interesting to consider a powerwall?

“Many growing companies in the Netherlands encounter the limitations of grid-congestion nowadays. This includes that the electricity provider decides a maximum amount of grid-usage for the company. Let’s give an example. The electricity provider limits the grid usage on 60 kW. If a company then needs 110 kW, during peaks, a powerwall will bridge the gap of 50 kW. This makes the powerwall an excellent solution for peak-shaving of the power demand.
Though not only for companies, also for private home owners a powerwall is a serious consideration. Especially when there is more than 50 Amps electrical service needed. For example, when you need enough energy to charge two electric cars and a heat pump.”

Tesla EV charging station

There are 6 electric vehicle charging stations in the parking lot. This will be expanded to 20 connections in the near future.

Which MG batteries would you recommend for a powerwall?

“We advise either the LFP or HE batteries series. The HE-series are very appropriate when the batteries are not required to be completely depleted or entirely full-charged. The LFP-series are excellent for performance. This means when there is a need for high levels of energy.”

During the interview, several benefits about using a powerwall were mentioned by Gerard. To list a few:

  • Making use of solar power
  • Reducing peak-demands from the grid (peak-shaving)
  • A solution to electric grid congestion problem
  • Energy for self-consumption

Gerard explains: “All electric equipment in the building use the energy from the powerwall. For example LED lights, computers, machines and even the air conditioning. Furthermore, we have six EV charging stations to charge electric cars.”

The company is expanding, as a result of the growing interest in Lithium-Ion batteries. How do the plans concerning the powerwall look like?

“Because of the scalability and modular design of a MG battery system, it is easy to enlarge the capacity of the energy storage system.
We have ideas about going off gas, and invest in an electric heat pump. This would then also mean expanding the solar panel array, and adding batteries to our storage system.
Another wish is to be able to charge 20 electric cars. So, step by step this powerwall will definitely be expanded.”

Lastly, is there any advice you would like to give to others who are considering investing in a powerwall?

“Yes, certainly. Don’t look at the investment of this one moment, but keep in mind where you want to be in 5-10 years. It will definitely be worth it!”

See the links below to get more information. Also feel free to contact MG Energy Systems when you have any questions. Perhaps there would be a possibility for a cup of coffee and a tour d’entreprise to see this ‘wall of fame’ in person. COVID-safe of course.

Gerard van der Schaar was interviewed by Bieuwkje Kooistra (April 2021).

Charging electric cars on PV solar

Installation and technical specifications of the MG Powerwall

  • 3x Victron Quattro 15 kVA
    3-phase configuration
    grid connected
    peak-shaving
  • 400x Solar panels total power 112 kWp
  • 15x Victron Solar MPPT DC solar charge controllers
  • MG battery bank
    48 pieces HE200 batteries
    Total capacity 240 kWh
    System Voltage 48 Vdc
  • 6x Master LV
  • 6x MG Energy Monitor including free access to the MG Energy Portal

Related links

Serengeti Project
https://www.mgenergysystems.eu/2019/07/04/first-resort-in-the-serengeti-to-run-entirely-on-solar-electricity-with-mg-batteries/

Victron & MG Energy Systems battery solutions
https://www.victronenergy.com/live/battery_compatibility:mgenergysystems

Related products

MG HE series
Product information of the installed batteries
https://www.mgenergysystems.eu/products/mg-he-series/

MG Master LV
In addition click on the link below to gain more information about the installed BMS
https://www.mgenergysystems.eu/products/mg-master-lv/

MG Energy Monitor
Furthermore for stand-alone systems use this advanced touch-screen monitor.
https://www.mgenergysystems.eu/products/mg-energy-monitor/

In cooperation with:

Provinsje Fryslan logo