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Solar Power

Started by reconair, 07/17/2012 11:27AM
Posted 07/17/2012 11:27AM Opening Post
Has anyone tried solar power for their observatories? I just goy mine built, but haven't run electric to it yet. Seems to me that solar power would be ideal for an application like this.

Here's my observatory


Attached Image:

reconair's attachment for post 55879

Scott Busby
A.K.A. Reconair

Carpe Noctum

Mortal as I am, I know that I am born for a day. But when I follow at my pleasure the serried multitude of the stars in their circular course, my feet no longer touch the earth.
- Ptolemy,c.150 AD
Posted 07/17/2012 05:00PM #1
Yes, my observatory is completely off the grid and has been running solar for more than 6 months. Seeing Monitor, AllSky Camera, Weather Station, Dome, Mount,Camera and related network and comupters... www.hbastro.com

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hbastro's attachment for post 144813
Posted 07/17/2012 06:56PM #2
Louis Busby said:

Has anyone tried solar power for their observatories? I just goy mine built, but haven't run electric to it yet. Seems to me that solar power would be ideal for an application like this.

Here's my observatory

Hi Louis, Hi All,
OK, I'd like to make two points here.

First, my observatory is solar/battery powered and it works. I only operate a Losmandy G-11 digital drive, but have more than enough capacity, and it cost under $300. If you have reasonable sunshine (very like the day before evening observation) I'd highly recommend solar power.

Second, my observatory is located in the desert. It's an itchy, scratchy place with critters that have fangs and poison or drag off your house-cat. During the day buzzards circle my house. Not something out on the road... My house. The few times a year we get rain, it comes down by the bucket. Then we're back to itchy & scratchy, put your head in the oven to cool off type of heat. So, under these conditions, solar power is bound to work.

As for those of you with gorgeous photos of observatories in cloudy places surrounded by green forests, well I'm not too sure solar is going to work.

Steve
wink
Posted 07/18/2012 07:46AM #3
Louis,

If that is a typical day--I'd say solar is not a good choice....too many clouds.

I am sure solar can be done, but you would need lots of batteries, etc. to assure good power through the night with computers, power to the dome, etc.

Alex
Posted 07/18/2012 07:32PM #4
Ok so here some simple thoughts on the subject of solar powering your home observatory. Life is always more complex, but this is a start. I went through a similar thought process for sizing my solar installation.

An efficient computer <2amps at 12 volts
CCD Camera <3amps at 12 volts
Mount <2 amps at 12 volts
Dome normal rotation for imaging 2 amps at 12 volts continuous.
Brings the total to 9 amps round up to 10 amps at 12 volts or 120watts running 10 hours during the winter and 7 hours during summer depending on your latitude. That’s 1.2KW needed.

Figure 30% of rated output from the solar panels so size the panels for 600watts/ hour based on 6 hours of potential sun during the winter but expect 2 hours again depending on your latitude. This says you need 600 watts of solar panels for 1.2KW energy demand.

Size the batteries so that you can run several days without a complete recharge figure 1200 watts or 100 amp hours for the 2 days you need 200 amp hours of battery. ~(6) average deep cycle car batteries assuming 35amp hour batteries. Again chargers and charge controllers are less than 100% efficient and you will need to take this into consideration.

I had no option, either run a generator or do a solar installation, solar makes a lot less noise and is less likely to breakdown or catch fire.

So unless you don’t have an option or just want the good feeling of renewable energy, and it does feel good, the costs are high. Being close to the house you can always augment a minimal-inexpensive solar power system with household power when needed.…

I post voltage and current values for my installation at www.hbastro.com...

Best regards,
Dave
Posted 07/22/2012 04:15AM #5
Thanks everyone for the input. Based on the cost of such an endeavor, I've decided to go with shore power. An electrician was out yesterday to discuss my requirements and I expect a quote tomorrow.

I'm looking now at running electrical 200 feet from my house to the observatory, adding three "in observatory" dual receptacle outlets and one external weather protected dual receptacle. All on a separate GFPI circuit.

Aside from the equipment I've already enumerated, I intend on either running a small electric fan or getting one of those small room portable air conditioner/de-humidifiers. I'm thinking a small fan would keep air moving on cool humid nights to reduce or eliminate dew issues. The AC/De-humidifier would be used for limited environmental control inside the observatory when its sealed up during the day. Any thoughts on these accessories.

Also, what really should my concern be regarding lightening strikes/grounding of my system? I live in N. VA and I get some pretty good late afternoon T-storms through here in the summer months.

The climate/sky condition here is generally excellent in the fall, winter, and very early spring. Cold in the winter, down to about 32 and occassionally lower, but generally in the range of 35-45 daytime and 32 down to 15 night time. Nightime observing is really excellent. Summers are hot, hazy and very humid. My observatory is located on open old pastureland near a 2 acre pond. Dew is a serious problem for unprotected equipment in the open.



Attached Image:

reconair's attachment for post 144860

Scott Busby
A.K.A. Reconair

Carpe Noctum

Mortal as I am, I know that I am born for a day. But when I follow at my pleasure the serried multitude of the stars in their circular course, my feet no longer touch the earth.
- Ptolemy,c.150 AD