Applying the principles of the stand-alone power systems standard (AS/NZS 4509.2) to demonstrate how to calculate the solar panels required and battery storage for an off-grid system once the energy demand has been calculated.
Brilliant! Thank you Smart Energy Lab for sharing this video. In Papua New Guinea we do our calculations based on 5 daylight hours due to more sunlight because we are much closer to the Equator. Thank you again. Greetings from Madang, Papua New Guinea!
Very enjoyable as I start my solar PV/Battery journey here in southern Illinois. As a start after receiving my first PV estimates, I UPSIZED each proposal. Most vendors started with a PV system that covered about 86% of my annual usage. I kept increasing the number of 405-watt panels until I got to 125% and was still within my budget. Adding batteries next year so am hoping for more choices like the Tesla Power Wall 3 and lower prices. Again thanks for the lesson and valuable information.
Hi Glen, thank you for the lessons. I have a question, for a stand alone system without backup system, do we need to consider the amount of energy required to charge the battery when sizing the PV? if yes, how should we do it efficiently? Thank you.
Are you not going to adjust the size of the pv system or the power capacity once the day of autonomy goes beyond. coz i think the charging of battery will also be affected seems on the computation is good only for the 9000wp.
Excellent video thanks ! Please, any explanation why battery voltage is set to 52 V ? is it something special about NZ ? In my country, common battery system voltages for solar systems are multiples of 12V and include 12V, 24V, 48V, and sometimes higher multiples such as 72V or 96V.
Mostly it’s the coulombic efficiency of charging at a higher potential than discharging. Check out the Battery Test Centres real world results. batterytestcentre.com.au/project/lithium-ion/
Imagine: this example shows 36kWh battery ESS for a home using only 9kWh/day. So a home using 36kWh per day needs a battery ESS of 144kWh ! Expensive. Some national electrical codes will not permit battery storage above 20kWh meaning they basically BAN off grid solar, in the name of safety.
My system was specified like this by the specialist power supplier I bought from and it is a DISASTER! It can fail and shuts down when demand is at a peak even though battery bank is like 90% full. This is due to the batteries not being able to supply high loads because 1/. there aren't enough of them to spread the load out 2/. they are lead-acid type and not suited to high loads. I have a backup generator and so chose to have only two days autonomy to reduce the costs (and the embodied CO2 emissions). The result is too small a battery bank to do the job on even 1 day. Maybe li-ion would have been ok but even they must have their limits. So in A. of your calculations you need to consider not just the TOTAL Ah demand but also the MAXIMUM power demand at any one time and check if the batteries can handle this.
You are correct - this formula is for sizing energy storage and PV generation only. For sizing of the inverter and maximum discharge rate of the battery system you would need to consider the maximum coincidental demand on the battery from the loads. I'll make a follow up video on sizing for maximum demand soon.
