Greenbuddies tips – March 2021

Source: Adobe Stock

Battery Storage System Markets Have Taken Off

In this issue of our Newsletter we decided to invite our Battery Storage System product manager, Marc Sottana, to address a hot topic in the renewable energy market. – We will specifically discuss the latest in the segment of battery storage solutions, a sector that is very close to our hearts at Greenbuddies Charging.

Battery storage is the fastest responding source of power on grids, and is used for multiple purposes, obviously stabilising grids in general, shaving or shifting peaks of consumption, ensuring uninterrupted power supply in power-outage sensitive types of operations, completing consumption diagrams for renewable system operators, etc. Battery storage systems may be used to shape fully-fledged power plants used for short-term peak power and ancillary services, such as providing operating reserve and frequency control to minimize the chance of power outages.

Battery costs have more than halved in the last five years. Battery storage has benefited from the economy of scale in the automotive sector and around 90% of lithium battery demand will still come from EVs over the next two decades. Specifically designed for PV + storage applications, this year the first lithium battery storage solution providing a 20-year performance guarantee was released to the market.
Falling prices and maturing battery technologies are taking the industry into a new phase of economic viability. The fast changing electricity system is beginning to realise the value of battery energy storage.
There exists a strong potential for battery energy storage to provide ancillary services to support grid stability. Last February the resulting collapse in power generation in Texas left millions without electricity. Less than 3 weeks later it was made public that Tesla is building a massive 100-megawatt energy storage in Texas to improve the efficiency of the grid and increase capacity at peak hours.
Behind the meter, residential PV + storage is actually the most dynamic market with support of subsidies for self-consumption in most European countries. For customers, savings on electricty bills are up to 70% and a return on investment is made in less than 10 years.
Last public green policies are now creating new oportunities to boost the development of micro-grids and self-consumption in commercial and industrial markets. Investing on a PV + battery storage solution turns the variable cost of electricity into a fixed cost for a 20 years minimum period while saving money. Electric vehicle charging applications for residential and commercial markets are going to grow at a phenomenal rate. The number of installations combining solar roofs, battery energy storage and charging stations for EVs is increasing rapidly. There are 10 million EVs on the road today, forecasts expect 100 million in 2030 and 400 million after 2040.
Choosing a battery energy storage system involves developing a long-term vision whereby a wide range of technical, environmental, legal and financial parameters come into play. 
At Greenbuddies Charging, we assembled a team of experts to support our customers across all stages of their battery energy storage project: consulting, feasibility studies, delivery, installation, commissioning and maintenance. 

Greenbuddies Charging continues to build strong partnerships with key players in the rapidly evolving PV and battery storage industry.
At Greenbuddies Charging, we love to share our experience – if you want to share your project with us, do not hesitate to contact us!

Soil Report As An Important Part Of  The Project Documentation

A soil report is an important document for every ground-based project. Through this report we are able to obtain information about soil properties on a given location where a power plant is to be constructed. As a result of collecting this information we are able to estimate the extent to which an anchoring construction will be challenging, thus having an effect on the cost and speed of eventual assembly.

In a case where the soil is permeable and the construction can be anchored securely, the columns are hammered into the soil directly – this way of column installing is called ramming. On the other hand, if the soil is not permeable or is packed with stones, the process of ramming will damage the pillars. In this case it is necessary to drill holes for pillars first, after which the pillars can be placed. Once these are placed in position, the holes are filled with concrete to ensure utmost dependability. It is also possible to drill the holes, fill them with concrete and whilst the concrete is still in a fluid state, place the pillars.
Prior to commencing the assembly of a solar park with an output of 3 MWp in Wriezen near Berlin, Germany, we received a soil report conveying that the ground is primarily made up of sand, thus suitable for simply ramming the pillars. However, in the very early stages of ramming, we realized that despite there being sand, there were also plenty of rocks – making the process more complicated. Specifically speaking, this unforeseen circumstance caused some pillars to be damaged during the process, or they rotated into the wrong position after touching with a stone in the soil. The end result was that we needed to change the method of installation through the use of diamond drilling to prepare holes for pillars first, then install the pillars into the right position and finally fill the holes with fast-drying and frost proof concrete. Without these changes in the method of installation the construction would be cheaper, and the implementation time would be shortened.
As a result of this experience we are acutely more aware of the importance of performing a well-founded and detailed soil report, as the accuracy of the outcomes could have a massive impact on initial investment as well as duration predictions. It is therefore of the highest interest to both the investor and the contractor that the study on which the soil report is based is of exceptional quality.

Mobilization Within 14 Days During Construction High Season

Less than two weeks had passed since the signing of the contract for the complete construction of a 15.6 MWp ground-based PV plant in France, and two excavators began digging the first trenches. We were expected to dig 2,000 m3 – almost double the usual amount – due to the fact that the location was divided by a service road into three sectors.

The ramming of the pilots was slowed down as a result of coming across large stones in the ground. We even came across an immovable “dead rock” as local French farmers call it, in three places. We hammered the pilots as best we could and subsequently performed tensile tests- verifying that we would meet the calculated pulling forces as the embedment depth was lower than required. We developed a new method of strengthening and extending the piles so that we could achieve the required values without concrete foundations as a result of the soil being too soft in 26 places. The landowner wished to keep his land in its original condition, thus piles without concrete foundations were required. Having sorted out all the above, at the end of October we supplemented our Orteco 800 driving machine with a powerful ARMIVAN AI1200, helping us ram more than 10,000 pilots in terrain with a slope of over 5 ° east-west.
The general contractor’s requirement was to place half of the panels and hang the inverters by Christmas. This was essential so that the conditions of the construction insurance were met, meaning and there was no need to take out additional insurance increasing the construction costs. The first three containers arrived on Friday December 4th. Despite unpredictable Covid-19 travel restrictions, we were able to increase our staff to 75 for the two weeks before Christmas. Thanks to the maximum effort of all the people and machinery involved we managed to lay almost 17,000 panels and install all 50 pieces Sungrow SG250HX inverters in 10 days.
Cooperation with the locals proved to be very useful for us. The French locksmith quickly made us jigs for straightening the assembly system, while the farmer’s neighbor transported the boxes with panels by tractor and trailer all over the construction site. This meant that we could get them to the distant corners of the PV plant faster and without too much difficulty. The only disappointment we faced was that the French bureaucracy took three-months to issue a construction auxiliary grid connection. We intend to learn from this experience for following projects by applying for a connection well in advance – allowing us to be energetically green from the very beginning.
Measurement and preparation for commissioning is currently underway with the participation of our elite team of electricians. In this project the client’s requirements are above standard in all respects. DC strings are measured at 1500 V in accordance with IEC 62446-1. In addition to Voc, Isc, Riso and polarity, we also measure irradiation, air and module temperature. To measure the I-V curve, the standard requires irradiation of at least 400 W / m2. We, however, must wait for a beautiful sunny day to be able to make the required measurements due to the fact that the client requires more than 700 W / m2 to make the values reflect actual conditions. A special measuring car had to come to Paris to measure VLF medium-voltage cables, as this test is not standard in France.
We are already working on another project in the vicinity for a large local construction company- having been impressed by our our quality work and particularly the full EPC delivery. We believe that we will start the new project in 4Q, 2021 and take advantage of the favourable climate and thus extend the construction season. A significant contribution to the smooth progress of the construction was the personal participation of native Frenchman Marc Sottana who, in addition to project management, mainly deals with battery storage technologies at Greenbuddies Charging, s.r.o.