Notes from Windward: #67
Working on the Power Lab
getting the small container ready to generate power
Last month we worked hard to get a 20' shipping container moved into position to house the equipment that we'll initially be using to generate solar-steam electricity. And for the last week we've been dealing with a "weather event" that brought us more snow than the last four years combined, but we've gotten past that and are starting to get back to work on our long term projects.
The first step was to finish leveling the container. We'd gotten it fairly close before the snow came, but it needed to be raised on the eastern end before we started to move a bunch of gear in. Containers can take a lot of weight as long as you're lifting on the strong points such as the end corners, but they're weaker in between those points, and once they're loaded up with stuff, you have to be careful to not exceed the strength of the steel runners.
Jay took a hand with the farm jack while we added another rail road tie under the eastern end. Not perfectly level, but close enough given the soft ground. If we need it more level, we'll deal with that once things dry out.
The inner wall of the container was covered with 3/8" plywood which needed to be removed so that we could affix a sheet of 3/4" plywood. Some of the equipment we'll be mounting will be too heavy to rely on the thinner material.
Self-drilling metal screws were used to secure the 3/4" plywood to the container wall.
The next step in getting the power lab on line involved bringing in power via what's essentially an overgrown extension cord. Rather than just using a standard circuit breaker box, we went with an out-door style box that features ground fault interupter circuits. While the container does provide a closed-in area, so an indoor box could have been used, but it's still a steel box and there's often some degree of condensation inside a shipping container so we intentionally went beyond the necessary minimum and installed the safest system we could come up with.
Once the main circuit box was in, we proceeded to mount the powerlab's grid-tie inverter and the power controler that matches the voltage delivered by the photovoltaic panels to the needs of the battery/inverter combination. The basic strategy is that we'll be experimenting with a variety of systems that will produce direct current to charge the powerlab's batteries. When the inverter sees that the batteries are fully charged, it diverts the surplus energy to the grid thereby running our power meter backwards.
Notes From Windward - Index - Vol. 67