Gochermann Solar Technologies

Company Contact	Oliver Gochermann
Company Contact Email	oliver@gochermann.com
Skype ID	gochermann
Whatsapp/Facetime	+49 1712943311
Midsun Contact	Michael Shiozaki

Background

Gochermann Solar Technologies, based in Germany, is a family owned encapsulation company. Probably the most widely used of the companies in the industry, they’re experienced with silicon and GaAs cells. Previously the encapsulation company used for MSXII and MSXIV, there was some friction at the end of MSXIV due to delay in payment from the university finance department, further delayed by COVID-19 related closures.

Technical Details

Maximum Module Size	7x4
Cell to cell spacing	0.6mm
cell to module spacing	2mm
Cell height	0.7mm

3M VHB tape provided for free, thickness of 1.1mm. They are capable of having terminals split across physical modules.

Timeline

July 22, 2019 (Outgoing): Initial e-mail to Gochermann. Stated that we are building a 4-seater and considering the Le1 cells. Asked for opinion on initial layout, thoughts on making the array flush with the roof of the vehicle and what would the ideal time to order is.

July 25, 2019 (Incoming): Acknowledgement from Oliver that the email has been received but Gochermann is currently extremely busy with WSC arrays and will respond to the email shortly.

Aug 6 2019 (Incoming): Gochermann gives a counterproposal (tab 4 of the excel spreadsheet), where modules are modified to fit the 7x4 maximum manufacturing size. Solar modules can be manufactured with multiple terminal pairs. Le1s are likely not available (MSXII used Me1s), Bin Me3 cells were suggested at a slightly larger size (max 322 on the car). Generic quote attached for 326 Me1 cells. Recommends purchase order should be submitted in January 2020 after iterations of the array. Noted that modules can be cut into any shape to follow the edge of the roof.

Sept 16, 2019 (Outgoing): Apology for delay in response, will have a counterproposal during the week. Asked when GST would know prices for E66 cells to help us decide which cells to use. E66 cells would reduce the cell count to 322 on the car, possibly impacting our overall layout. Also asked what the approximate timeline would be after submitting an order and when would be best to answer. Third question is what would the impact of changing MPPTs affect our layout given our consideration of Elmars.

Sept 24, 2019 (Incoming): 1. Solar cells can be ordered and shipped to GST. Sunpower usually ships 150 packs but we can order the exact amount from GST. 2. usually deliver 6-8 weeks from the purchase order. Recommends January order for March/April delivery. 3. Solar modules and cells will likely be unaffected.

Oct 22, 2019 (Outgoing): delay in our cell array due to rearrangement from the surface area of our car being different from what we thought it was. Asked to confirm that the cells could be cut in curves to align with the roof panels and how it would affect the array electrically. Also asked about costs of curved or half cells. (received an out of office reply and a failed send, possible Oliver did not receive this email)

Nov 5, 2019 (Outgoing): Sent new layout and asked for a rough quote. Stated we would be ordering cells from Sunpower pending availability and numbers.

Nov 6, 2019 (Incoming): Major concern highlighted based on the dimensions of the array that we noted. Noted that tolerances for edges were 2mm and 0.6 between cells. We require extra space all around the edges and an extra 1mm on the outer edge should be accounted for. Notes that Le3 cells will likely be the same cost as previous Me1 cells and the cells are bigger.

Nov 13, 2019 (Incoming): Checking to confirm that we received the email.

Nov 13, 2019 (Outgoing): Delay in response due to awaiting confirmation from aero team about a new layout that is proposed to be sent back in the next couple days. Would be happy to schedule a call to clarify things with Oliver.

Nov 18, 2019 (Incoming): Oliver is based in UTC +1, call on Wednesday will work for him.

Nov 18, 2019 (Outgoing): Asked to schedule call for 12pm-1pm (UTC+1) (6am-7am EST)

Nov 19, 2019 (Incoming): Provided skype, whatsapp and facetime information and locked in call for 12pm UTC +1.

Nov 20, 2019 (Call): Skype call with Oliver (Details to follow when I find them).

Nov 22, 2019 (Incoming): Thanked us for call as it helped him understand what we wanted better. Prepared two quotes for us based on Me1 cells (for the price of Le1 cells). One quote is if we provide the cells from Sunpower, the other is if GST provides the cells.

Dec 16, 2019 (Outgoing): Questions about the dimensions of the finalized array and if there are any technical documents to go with it.

Dec 19, 2019 (Incoming): Provided an excel sheet showing the exact dimensions and asked if we were ok with the module to MPPT allocation. Can create an invoice over any amount depending on how the university creates budgets. Exact terminal locations determined by our physical chassis constraints.

Dec 24, 2019 (Outgoing): State consideration of 12 Nomura MPPTs or 3 Elmar MPPTs for array. If Nomura is selected, some modules will need to be reallocated due to the minimum number of cells needed per module.

Jan ___, 2020 (Call):

Jan 15, 2020 (Incoming): Order confirmation from Gochermann, shipment price of 170 euros.

Jan 16, 2020 (Outgoing): Layout in the order confirmation is the incorrect layout. Our mistake for not recognizing and assuming the 6-5 layout was the most recent one sent to them. Ask if it is possible to switch this.

Jan 17, 2020 (Incoming): First half invoice.

Jan 17, 2020 (Incoming): Array construction likely begins Feb. 3. Asks that we re-outline our modules in Excel for clarity. Concerns about our layout breaking rules again with regards to max size of modules.

Jan 19, 2020 (Outgoing): Sent updated spreadsheet with clearer borders and terminals tab. Noted how the dimensions were outdated and have been removed. Half cells can be allocated to either front MPPT.

Jan 21, 2020 (Incoming): Concerns about interweaving modules due to the spacing between module to module will affect all sides of the interweaved cell. Requests a drawing of each individual module