[glend (Glen)]

Peter my single pier observatory is off-grid now. Because I make regular dark site trips I already had all the 12V gear I needed to take the astro equipment off-grid. When I built my observatory I laid in a single 10amp AC cable from my shed solar system inverter, the rest of the power requirements in the observatory use standard 12V supply from my dark site batteries which I keep in the observatory and which are charged by the shed solar system during the day. The key element of my system is 500W of solar panels on ground mounts dedicated to charging (through a 30A MPCC charger) my shed battery bank ( 4x 100ah Deep Cycle batteries) with a 5000W Sine wave inverter. The single most energy hungry device in my observatory is the DSLR camera cooling system (12V, 6ah on max cooling), and this is powered off the inverter in the shed or via the observatory batteries depending on which adaptor is used. My observatory laptop runs off the AC feed from the inverter, or its nine hour internal battery. As long as you don't want a fridge, coffee makers, etc in the observatory it is pretty easy.

I looked at wind turbines but they are expensive and relatively low output and almost exclusively three-phase AC output requiring a controller as well. In NSW there are regulations regarding their use which make it almost impossible in residential areas - separation distances, noise, etc. I could not make a case for wind; but if you lived on a rural property I guess they could be useful.