System and installation:
Post date: Oct 03, 2019 3:1:38 AM
One of our old genset is dying after 18 years of good service. Instead of buying a new genset we have decided to invest the same money in an hybrid PV solar/Batteries/Genset system.
Our remaining generator is a 3 phases 23KW Yanmar generator. It can be remotely start and stop via a dry contact relay.
I have to design and size the system around this generator.
Why hybrid:
We have chosen an hybrid system because of our location. we are located just on the equator which is a big advantage for the sun inclination (23 deg between solstice and equinox that allow us to lay our solar panel flat) but as well have an important cloud coverage toward the year and unfortunately new phenomenon as massive pit fire in Sumatra can also affect considerably the sun exposure.
Our remote island location does not allow us to have access to public electricity and we always have been autonomous in energy production. As an hotel/restaurant we have lot of fridges and freezer who require 24h/7d of electricity. Our very humid and saline environment is very harsh for mechanic and any rotating equipment which is not use is very quickly going to rust and jam.
With all of that in mind it was obvious to choose a system which is able to provide electricity from solar panel and battery and from generator as well to cover the rainy cloudy days our hazy pit fire days and to have the generator running at least 01 hour every day as routine and topping up the batteries.
Requirement:
The generator is able to provide 7Kw per phase on 230Vac and i will limit the power to 5Kw per phase (15KwTotal) to avoid to push my genset to it's limits.
Therefore the system must have 3 Hybrid inverter of 5kw each, working in parallel mode sharing the same battery bank, each phase of the genset feeding one inverter.
Each inverter should be fed with it's own solar panel array of max 5Kw.
My budget should be around 20k Usd.
Research and sources:
To help me to design the system i have found online some useful sources and references.
The global solar atlas: https://globalsolaratlas.info/map
Solar irradiance and tilt in north sumatra by Muhammad Irwanto
PV installation calculator http://www.calculationsolar.com/calculate.php#
Cable size wire calculator: https://solarpanelsvenue.com/calculator/wire-sizing-calculator/wire-sizing-calculator.htm
DC cable sizing Tool: https://www.solar-wind.co.uk/info/dc-cable-wire-sizing-tool-low-voltage-drop-calculator
Inverter manufacturer wesite such as mpp solar: https://www.mppsolar.com/v3/
Schematic:
