Samanco Solar Symposium

Samansco recently hosted a solar symposium and as much as it was them announcing a couple of pretty interesting new products, it’s some of the presentations from their suppliers that caught my attention. 

The ideal solar panel

Longi was present at the symposium and for those that are not familiar with them, they are a Tier 1 solar panel manufacturer. What this means is they have the capacity to design the panels and test the performance of their hardware.

Bloomberg New Energy Finance (BNEF) has developed a tiering system for module manufacturers
which employs a set of criteria to qualify for Tier 1 status (i.e. the most bankable module
manufacturers in the market):

Must have provided own-manufactured, own-brand products to six different >1.5MW projects,
which have been financed non-recourse by six different non development banks, in the past two
years.

Module maker must be in the public domain and must not have filed for bankruptcy or a form of
insolvency protection, or experienced a major default on bond payments

BUT, as BNEF rightly points out their classification is purely a measure of industry acceptance,
and not a testament to the quality of product or the likelihood of bankruptcy of the manufacturer

Longi presentation

The actual construction of a solar panel consists of a shiny silicon wafer, similar to the silicon wafers used to make chips powering electronic devices. Longi takes this wafer and prints a custom design on it to turn it into the finished light-gathering cell. 

Longi is the largest producer of these cells with some of the more popular solar module brands using cells manufactured and supplied by Longi in their modules.

The report shows that in 2022 LONGi has shipped a total of 85.06GW of monocrystalline silicon wafers, including 42.52GW for external sales and 42.54GW for internal use, steadily ranking 1st in global shipments of monocrystalline silicon wafers for 9 consecutive years. In 2022, LONGi shipped 46.76GW of monocrystalline silicon modules, including 46.08GW for external sales and 0.68GW for internal use, steadily ranking 1st in global shipments of modules and market share for 3 consecutive years.

Longi 2022 annual report

They also hold a number of records when it comes to the efficiency of their cells in terms of watt per unit area, performance across a wide range of temperatures, and low light performance. 

One of the lesser-known facts about solar modules is that their output is affected by temperature. The higher the temperature, the less peak power they produce which is lower than their rated output. As a result, in winter, solar systems produce more power than in summer. 

This is something that is crucial when determining the capacity of solar modules that you will feed into an inverter. You might find that a system whose solar array is built to the maximum capacity of the inverter might end up producing more peak power in winter than what the inverter is rated for.

Samansco’s new products

The star of the show was a new Energy Storage System (ESS) made by Rebel, an American company specializing in alternative power and backup solutions. This battery is called the Rebel Ultr5 and it’s a 5KWh battery. A majority of the batteries in its class are still at 4.8KWh so it is a higher capacity.

Some of its specs include a 90% Depth of Discharge (DoD), a 6000 charge cycle rating, and the flexibility of connecting up to 16 of them together for an 80KWh ESS capacity. It’s also IP53-rated making it resistant to some moisture. Let’s see how it compares to other batteries in its weight class.

	Rebel Ultr5	Pylontech UP5000	Blue Carbon UU 48-200/250/300	BYD BATTERY-BOX LV Flex Lite
Capacity	5.12kWh	4.8kWh	10.24/12.8/15.36kWh	5kWh
Output current	75A	50A	100A	70A
Depth of Discharge	90%	95%	80%	100%
Charge cycle life	6,000	4,500	6,000	–
Single string capacity	16	16	8	64
IP rating	54	20	–	20
Warranty	10 years	10 years	5 years	10 years

Compared with a couple of brands present in Zimbabwe, it’s a competitive product. Unfortunately, the pricing is not yet available to compare but expect it to retail at around the same price as the Pylontech battery.

There will be a firmware update coming in for the battery allowing it to be monitored remotely. It also can only operate when communication to the inverter is present. If there is no communication, the battery enters sleep mode and stops supplying power. Speaking of inverters, the Rebel Ultr5 was tested for full compatibility with the following inverters:

• REBEL MAX
• PHOCOS ANY-GRID
• SUNSYNK/DEYE
• VICTRON
• MUST
• SMA
• SOLIS
• PYLON
• GOODWE
• SOL-ARK
• KODAK