Don't know why you want to get off the grid, but if that's what you want to do it's up to you. The grid is cheap "storage" and backup. Unless someone invents really cheap batteries you're going to spend more by running an independent utility company.
That said, if you want to get off the grid I would advise doing it in stages. For now hook your shop to the grid. Then put some panels wherever you have the best sun. House, shop, ground-mount in the back yard - matters less than good sun. And the ability to scrape off the snow if that's an issue where you live.
Ideally you should be able to get to your panels and adjust their angle about four times a year as the Sun rises and falls in the sky.
Do that and you start out with a "grid tie" inverter. It will take the DC from your panels and convert it to 120vac. That 120vac will get fed into the grid on your side of the meter. The amount you use will replace the power you would have purchased from the utility company. It won't matter whether you use the power in your house or in your shop. Any surplus will feed back to the utility company. Depending on the regulations where you live you will get credit for power provided and can use utility company power later, or some other system.
By starting grid-tied you will qualify for the 30% federal subsidy and possibly state and local subsidies. Starting off the grid, you won't.
Later if you want to get off the grid you'll have to add batteries, a charge controller (to keep the batteries from overcharging) and a battery to 120vac inverter. You can get a 240vac output by "stacking" two inverters if you need the higher voltage for tools. When you pick your inverter(s) get one with a high surge capacity so that larger tools like table saws will start easily.
For my system I've got 1.2kW of panels, 16 - 75 watt panels. Mine are ground mounted so that I can get the snow off of them more easily, but I'm thinking about putting them on the roof as I've got some Douglas firs starting to shade them in the winter months. It's move the panels or drop some big trees that got much taller in the last ten years.
From around the middle of April until the middle of November I don't even think about how much power is in my batteries. I'm usually full by lunchtime. The only time I used my generator this last "sunny season" was one day when I was sanding floors and pulling a lot of power.
I installed my system when panels were about 4x as expensive as they now are. I'm probably going to add more panels in the next couple of years, especially if I move mine to the roof. That should really help me cut back on generator use. Not that I need the genny a lot, but I'd rather not be burning the gas if possible. And the panels should last for decades.
= new reply since forum marked as read
