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Air Conditioned Off-Grid Workshop

Equipment Specification

(1) Schneider SW4048 Inverter

(1) Schneider 60-150 MPPT Charge Controller

(1) Schneider InsightHome Gateway

(12) DEKA 8G27 Lead-Acid Gel Batteries

(9) 320w REC Solar Modules (2.88kW)

(2) 320w REC Solar Modules for R&D

(1) Midea 8000BTU Inverter A/C Model MAW08V1QWT

(4) LED Garage Lights 150W, 15000lm

The 16×20 structure was designed to have a 100% south facing roof for the solar modules:

The power system consists of a low-frequency Schneider SW4048, which can deliver 3.8kW continuously, with a 7kW surge rating.  The low frequency design enables it to start induction loads with ease, such as power tools.  It delivers 120/240 split phase AC true-sine power.

The 9 320w solar modules are connected in 3 strings of 3 to a Schneider 60-150 MPPT charge controller, which charges a bank of 12 DEKA 8G27 GEL batteries wired in 3P4S configuration for a usable capacity of roughly 6kWh at C/20 rate and 50% depth of discharge.  It is a 48vdc system.

The building is insulated, with an insulated roll-up garage door, standard entry door, and a window.

The window contains the Midea inverter window air conditioner.  This AC is exceedingly efficient, drawing around 350w at full power and having zero surge.  Much like a mini-split, it ramps up and down smoothly and maintains the temperature at 75f even on a 95 degree day.

The base load, including the A/C in June, consumes an average of 1.87kWh per day.  The 2.88kW of PV can produce up to 6.85kWh on the shortest winter day.  In the event of insufficient power due to extra loads or lack of sun, a generator inlet can be connected to supplemental power from the grid or a portable genset.

Heating in winter is supplied via a propane garage heater.

The real-time monitoring via Schneider Conext Insight supplies plenty of data: