Solar v2 – choosing the components

Since my first attempt at solar, I have learnt a few things and several new bits of tech have been introduced into the market. Some of the new tech include; all-in-one inverters, bigger “better” batteries, shingled solar panels and micro-inverters…

Time to take the learnings from my first solar project and scale-out

New Parts

An all-in-one solar inverters can include the following functions in a single device;

  • Solar Controller – MPPT (2x string inputs)
  • Inverter – Converts DC (48v) to AC (pure sine wave @230v, 50 hertz)
  • Battery Charger –
    • from Grid (AC -> DC)
    • from Solar Panels (DC -> DC)
  • ATS / Line mode – Flicks over to Grid if solar or batteries are low
  • BMS, Timers and Controls – Can program battery types, priorities and timers depending on how you want to power your loads and utilize your batteries.
  • Stats / Alerts – WIFI enabled

I have committed to an 8kW PV all-in-one inverter. My house doesn’t have a north-facing roof, but it has a NE and NW facing roof which isn’t too bad, the bonus of having 2 string feeds on the inverter means that each side of the roof will act independently without dragging down the total power output.

I’m currently running a few lead-acid batteries on my solar. I’ve been in two minds about whether I continue with batteries or go with a hybrid system that effectively uses the grid as a battery. I ended up deciding to go with batteries one last time, here in NZ the solar rebate is not really worth the effort of exporting – we typically get wholesale prices which can be 1/3 of the cost of power. I’ve also been pretty excited about how quickly the new LiFePO batteries can charge and discharge, so I’ve committed to a couple of 48v PylonTech batteries in a stack, totaling 7kWh.

Us3000 48v/74ah 3.5kwh Lithium Battery Solar Battery Pylontech 48v  Residential Battery - Buy Pylontech Us3000,3.5kwh Lithium Battery,10kwh  Lithium Battery Product on Alibaba.com

They can peak at 100A (15s) but the recommended rate is 37A each. At 48v this will give me a charge / discharge power rate of 3.55kW (37A x 48V x2) in total. In some cases it may be beneficial to charge with cheaper off-peak power from the grid.

Singled solar panels are pretty nice, with more surface area and better resiliency. I found a 480W mono Hyundai panel which I’ll use to build 2 strings of 4 panels. In total, this gives me 3.84kW (480W x 4 x 2)

In terms of power, for my next venture I decided to stay with the more traditional DC solar panels. There is however another choice thanks to the introduction of micro-inverters. These little devices convert power on each panel direct to AC, which includes several advantages (higher voltage, operate in parallel (independent of other panels). Each also has its own sensors if you want to see stats!

The next sections – powering things, ROI, the build, safety

Solar – In Summer

Power generation is up in summer :)

The last stat “Total Power (1M-7d)” gives me a view of how much power was generated over a 30 day period 7 days ago (so i can tell if power generation as an average is going up or down). Right now it power generation this on a downward trend.

(see previous post for winter generation)

Mi / Xiaomi Scooter Error codes

Scooter beeping? – check out these codes for a hint at what might be wrong…

Error codeDescriptionMalfunction part
10Dashboard and control board communication abnormal,check connected cableDashboard、control board
11Motor A phase current abnormal ,check control boardcontrol board
12Motor B phase current abnormal ,check control boardcontrol board
13Motor C phase current abnormal ,check control boardcontrol board
14Throttle hall abnormal,check electric throttle、dashboard and connected cabledashboard 、electric throttle
15Brake hall abnormal,check electric barke、dashboard and connected cabledashboard、electric brake
16Battery change MOS abnormal,check control boardcontrol board
17External battery change MOS abnormal,check control boardcontrol board
18motor hall abnormal,check motor、control board、connected cable.control board、motor
19Battery voltage abnormal,check battery、control board、connected cable.control board、battery
20External battery voltage abnormal,check battery、control board、connected cable.control board、battery
21Battery communication failed,check battery、control board、connected cablebattery
22Battery code failed,change batterybattery
23Battery default serial number,change batterybattery
24System voltage test abnormal,check control boardcontrol board、battery、external battery
25Undefined 
26Flash saving error,check control boardcontrol board
27Control code error,change control boardcontrol board
28Motor driver mos up-bridge short circuitcontrol board
29Motor driver mos down-bridge short circuitcontrol board
30Undefined 
31Program skip error,check control boardcontrol board
32Undefined 
33Undefined 
34Undefined 
35Unit has default serial number,change control boardcontrol board
36Undefined 
37Undefined 
38Undefined 
39Battery temperature sensor abnormal,change batterybattery
40Control board temperature abnormal,check control boardcontrol board、battery
41Exteral battery temperature abnormal,change external batteryexternal battery
42Exteral battery communication error,check external battery、control board、connected cabelcontrol board、external battery
43Exteral battery code error,change external batteryexternal battery
44External has default serial number,change external batteryexternal battery