Introduction

In this blog, I will run through my process for designing and building a complete solar energy system from end to end.

To start the design, we need to collect a little bit of information about power expectations.  A good place to start is your power company and your own breaker box.  

MAXIMUM POWER

First, we need to know what the maximum current you house can draw.  This can be as low as 40 amps and as much as 800 amps.  The most common amperage is 100 amps or 200 amps in newer houses and 60 amps or 100 amps in older houses.  All you need to do is find the amperage on your main breaker on your main panel.  Sub panels will possibly have smaller breakers, so be sure to check your main panel.

My main is a 100 amp, 240 volt service.

This information will be used primarily to size your power inverter and feed wire between the battery array and the  inverter as well as the feed wire between the inverter and the main panel.

You will also need to know your service type. This will most-likely be 240 VAC in most areas of the USA, but it could also be 380 VAC. 380 VAC is mostly used in industrial applications and rarely in residential service.  In a few rare cases, you may only have 120 VAC service, but this is obsolete in most of the USA.

DAILY USAGE

Next, you need to find your daily usage.  This will vary considerably from season to season, so its a good idea to find the maximum power consumed in one day for the entire year.  

Your daily usage will be measured in KWh/day.  This will be used (along with other parameters) to size the battery array.

For demonstration purposes, I will use 50 KWh/day as a design parameter.