Greenbuddies tips – May 2021

Source: Shutterstock

Electric Bus Charging

Quiet and non-polluting, electric buses have many advantages over their diesel counterparts. A few years ago, the majority of electric buses came in the form of minibuses as a result of the size and weight of batteries. Now manufacturers are designing electric buses of all sizes thanks to massive improvements in battery technology for electric mobility. The battery charging method also requires adaptations to existing infrastructure on routes and depots.

Slow charging at the depot is the most common method. Recharging time depends on the charging station power. It usually takes between 4 and 6 hours to fully charge the batteries- this is usually done once a day and often overnight. An additional recharge can be made during the day if buses return to the depot. The connection of the charging cable is done manually. A load supervision solution optimizes electricity consumption (smart charging) and ensures that the power limit at the depot is not exceeded.

Electric bus recharging solutions are evolving with fast charging. The new charging method consists of several quick recharges outside of the depot when the bus is at stops on the route or at the terminal station. Several manufacturers have come together with a solution whereby the bus is recharged through physical contact with an inverted pantograph. This means that it is no longer necessary to connect a cable in order to recharge the bus! In addition, these systems make it possible to reduce the weight of the on-board batteries, which in return makes it possible to reduce the weight of vehicles and so carry more passengers.

Electricity for bus recharging can be produced locally with photovoltaic systems to achieve 100% emission free transport. Shanghai has set up the very first solar power project for a bus depot in the PRC. Covering nearly 2000 m2, the solar panels provide enough energy to recharge 6 buses at the same time. The system also provides energy for other purposes at the facility and even feeds electricity back to the grid.
The future is undoubtedly one wherein green energy becomes the norm, and transport shall very quickly turn all-electric. Governments worldwide are facilitating this transition by supporting programs for the acquisition of electric vehicles and for the installation of new EV charging alongside renewable energy infrastructure. The e-Mobility revolution is inevitable and unstoppable. At Greenbuddies Charging, we are proud to be involved in this change together with our customers and partners!

Repowering 

In recent years, repowering on solar power plants has been increasing in the German solar market. Repowering on a solar power plant means the replacement of individual components, most often the solar modules. These replacements can be brought about due to various situations such as failure of the components, damage or theft. Most solar parks secure their revenues by the fixed price. Therefore, the owner wants to generate as much electricity as possible whilst simultaneously following all the rules so as not to commit fraud.

Accelerated degradation is also considered as part of damage to modules. Over the years the German network agency set a limit for what is considered natural degradation, the surpassing of which means accelerated degradation. The limit is degradation exceeding 10 % of original power during 10 years of module operation. The repowering of a PV plant whilst maintaining the subsidy is possible if complying with several conditions: new module power cannot be in sum greater than the original power output of the old power plant. Alongside this, old modules need to be disposed of by a certified company and in case the modules are changed due to accelerated degradation (under the 90 % of nominal out power in 10 years lifetime), the degradation must be caused by technological reasons, not by the i.e. dusting of modules etc.

Greenbuddies has already participated on several larger repowering projects over 3 MW. In reality this means to dismounting all the old modules, and careful preparation for transport. This is because the modules are often sent for testing before disposal at the manufacturer post-dismount, as they usually hold the guarantee for degradation. Furthermore, the DC strings must be adjusted since the new modules are more powerful, leading to differences in length of the strings. Before the start of a repowering project, careful planning is required gauging what material is fit for reuse, and what is in need of replacement. Usually old string cables in the ground can be reused, as well as some of the clamps if not affected by corrosion etc.

The repowering of a solar plant is often just as time consuming as the regular construction of a new solar plant as a result of the complexity. The same amount of time is spent on dismounting modules as would usually be spent on ramming and substructure completion. Placement of new modules is then similar to that on a new Pv plant, as it is with the string adjustment and measurements. The only advantage in the perspective of time is the absence of AC works at a repowering project. However, this is not always the case as exchanging old modules with new ones often opens up space on the substructure (due to the increased power of new modules). This free capacity can then be used to expand the power plant if extra capacity in the distribution network is available. An example of this is a project where we are completing repowering of an originally 5.7MW plant – the placement of modern modules allowed for an extra 1.5MW to be placed on the existing substructure, thereby increasing power generation by 25% on the same surface area as compared to 10 years ago.

Source: SPR Energie

New Sales Consultant on Board of Greenbuddies

We are getting more and more involved into the DACH market. This market is a key market for Greenbuddies since solar is increasing in popularity and strongly subsidized. Therefore is proved we need to have excellent people on ground in Germany, Austria and Switzerland to get close on new opportunities. From this year Jarmil Slesinger joined the team and we bring you an interview with him.

1) What has surprised you most about working with Greenbuddies?
It is stunning, how quickly a solar system can be built. One you have finished all the paperwork, teams of professionals start their orchestration and a new plant or rooftop installation is literally growing under your hands. Often people returning from their vacation and seeing a new PV plant do not believe their eyes.
2) What would you tell someone who is thinking about building a PV plant?
Do it, whatever the motivation is. Lower energy bills, preserving the Earth’s finite fossil-fuel resources or reducing air pollution. At the end of the day, all of these will apply and not only for the owner, it is a win for all of us. Our planet profits from each installed solar panel.

3) What do you think will change about the PV world over the next years?
Every European country is already working on a green agenda, plans how to become carbon neutral. For example, Austria plans to reboot its tax laws in 2022 and now evaluates the best way to put a price on ecologically destructive activities. China announced to reach carbon neutrality before 2060, following an earlier European Union commitment to do the same already by 2050. Electric cars are often in the headlines, but carbon neutrality will impact all parts of our lives and the importance of solar systems will continuously grow. In addition, further enhancements of energy storage systems will be critical to increase the ability of PV systems to replace the existing energy sources and enable long term turn in the energy market.

4) As a part of the PV team, what sorts of actual challenges do you see?
The spread of COVID-19 has heavily impacted global economics. Industries like tourism, airlines, and retail industry suffered immediately in the first quarters, but subsequent restrictions impacted production of raw materials and components and the shortages in the logistic did not satisfy global market demands. These days the ordering process takes much longer than usual and increased raw material prices negatively impact the costs.

5) What do you do when you aren’t working?
I love being exposed to new places, people, and cultures. I like to travel independently without prepared holiday packages. It does not matter if the destination is far or just behind your backyard. I love to taste and smell the local food, discover special places, and have a plan that may change at any given moment. Sometimes I stay off beaten paths because some places cannot be discovered without getting lost.
6) How would (someone) describe you?
Tireless optimist ?