Solar

function charge()
  for i=0, 149 do
    term.clear();
    term.setCursorPos(1,1);
    print("Charging... ("..tostring(150-i).."s)");
    sleep(1);
  end
end

function unload()
  for i=0, 239 do
    term.clear();
    term.setCursorPos(1,1);
    print("Unloading power... ("..tostring(240-i).."s)");
    sleep(1);
  end
end

while true do
  charge();
  redstone.setOutput("bottom", true);
  unload();
  redstone.setOutput("bottom", false);
end