Build A Solar Powered Storage Shed or Detached Garage.

In this project we build a 6000W solar system for a detached garage shed workshop. The shop was built earlier this year. We added photovoltaic panels, rapid shutdown and inverter to allow us to have power if the power goes down and also to feed power back into the utility grid for electrical credit to reduce out power bill. The total cost of the solar system was about $4500 and took about 24 hours to build (2 men, 3 days, 4 hours per day).

1 - Solar Electric System Overview

We purchased the components for this system from a solar supplier. The components we purchased include: racks to hold the panels, boots to attach the racks, photovoltaic panels, rapid shutdown with switch, wire connectors, 600V outdoor rated wire and inverter.Our average use is

about 700kwh a month so 4620 watts of solar is enough to make about 16kwh a day. (depending on the sun) 16x30=480kwh. We plan to expand the system with another 6 panels next year which will take it to 6000 watts.

2 - How To Get A Building Permit For Solar System

The first step is to check with your local building department and power company to find out what regulations there are for installing solar on your property. 
For our project we were able to install solar panels and have them feed the main power grid. This is called net metering and it involves connecting the energy you create to the main panel on your home and having the power company install an electrical meter that is designed to give you credit when the electricity flows from your solar panels back into the grid.

You will need to put together a One line diagram for your permit and to help you and your permitting agency understand how the system components will work together. A one line diagram shows all the components of the solar system. It shows how they are connected together and gives the critical information about each component.

Our diagram shows the panels as the starting point. We have two strings of panels, each with three wires, a positive, negative and ground.

The wires run from the panels into a rapid shutdown box. Some areas do not require this component so you will want to verify if you need it.

From the rapid shut down box the wires run to the inverter. The inverter will convert the power from DC to AC. There is also a low voltage wire running from the rapid shutdown box to a switch at ground level.’
The wires come out of the inverter and into the electrical panel.

Since our system is on a detached garage with its own electrical panel that is fed by the meter panel on the adjacent house we showed both panels on our diagram.

ONE LINE DIAGRAM

SITE PLAN

This is what our site plan looked like. It shows where the solar array is on the building and where the electric panels and disconnect are. You can download these documents by clicking on them.

This is solar.

STEP 2- Locate The Roof Trusses

Wires between solar panels are connected using the male and female plugs attached to each panel.

Install Zip ties to keep wiring off of roof.

The rapid shutdown box is installed at the end of the panel string, under the last panel.

The ground wire is attached to the grounding bolt on the shutdown box and goes to the inverter.

Other strings of panels are grounded to the system using a ground wire attached to the rails.

The rapid shutdown wiring is run from the shutdown box to the switch.

Wires are run from the rapid shutdown box into a flashing to go through the roof.

Wiring from solar panels running through attic.

Wiring running through wall top plate into wall from attic to solar inverter.

Wiring the solar inverter. The left side is the DC power coming in from the panels. The right side is the AC power going out to the Electric panel.

The ground wire runs through the box, grounds the box and the out to the AC panel. The ground wire on the 10/3 wire is also attached to the box.

The ground wires run to the AC panel and are attached to the ground bar. (this is different than the neutral bar)

The 10/3 wire from the solar inverter is attached to a 30 amp breaker inside the AC panel. The neutral wire is attached to the neutral bar.

The rapid shutdown switch is attached to the outside of the building so it is accessible.

Labels are installed on the inverter, the ac panel, the shutdown switch and the main meter panel. Check with your city for current code information regarding the solar system.

The final step is to install a new electric meter so the power will be able to run from our property into the electrical grid without charging us for the electricity.

View Our How To Build A Gable Shed Series

 

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