The power grid is the main infrastructure in the game, it is the net for electricity distribution and usage. You need to connect wind turbines, Solar Panels etc. that produce energy with energyconsuming machinery, tools, batteries etc.
List of power producing units
Your starter kit includes a number of solar panels, batteries, Power isolators, LED Panels and a transformer. You need the Transformer to make the Power Grid distribute power to an area around the transformer. As part of setting up a base the power grid can be seen here
To charge the batteries connect them to the transformer. Select a Power Isolator from Manufactured Blocks. Click on the batteries and on the transformer and then a wire should appear. If it doesn’t you can always manually link Power Isolators by right clicking on them in turn. You can see when a connection is possible: The wire turns from red to green. A wire can only stretch so far though, so you might need to break up long runs with more Isolators.
And finally to get power, we need a power source. Place the solar panels and link them to the transformer with power isolators.
This is a basic power grid that delivers enough power to run several LED panels. Remember that you need the batteries, though, since you can't use solar panels when it is dark. Wind turbines might run at night, but they need a minimum wind velocity.
See a video of Electricity distribution and usage.