This was a best guess posted the the web site by SamChurchill. Please refine as new information becomes available.

Let's estimate the power requirements of a stand-alone Access Point that includes a 2-way satellite dish, laptop and access point on a hilltop driven by solar panels.

RickLindahl, of course, is much more able to give a more accurate picture. But I want to analyse what solar power equipment might be needed for a hilltop Wireless LAN Access Point. These figures are ABSOLUTE GUESSWORK. It's just something to work from.

First, let's analyse the power requirements. I'm guessing on the power:

1. Echostar 360 Satellite Modem power: 50 watt X 1amp X20hrs/day=1000AH
2. Laptop Computer (Pentium-M) 20 watts X 1amp X 20hrs/day=400AH
3. Wireless Access Point 10 watts X 1amp X 20hrs/day=200AH
4. Total: 80 wattsX 20hrs/day=1600 Amp/Hours Daily

We only get sunlight perhaps 10 hours daily. It consumers 80 watts/hr times 20 hours/day, so we need to store maybe 160 watts/hrs times 10 hours (of sunlight) to fill our 1600 watt/hr batteries. So at least two, 80 watt Siemens Solar Panels or more likely 3-4 might be advisable. This whole watt/hour business doesn't look right but I'm going to go with it for the moment.

Here's a guide using a solar powered Ham Repeater:

• http://www.packetradio.com/solar.htm

• Four, 80 watt PhotoVoltaics ($350 each) - $1400

• SOLAR panel disconnect. ($50)
• Model C30A Charge Controller ($200)
• Battery Disconnect; Contacts must handle at least 20 amperes at charging voltage ($50)
• Battery bank of 13.8 VDC deep cycle (VOLTEC/Dynasty), low maintenance batteries ($200)
• Misc weatherproof box and masts ($500)
• Total ($2400)

Plus:

1. Starband (Wildblue, DirectWay) $600

2. Laptop ($1200)
3. Access Point ($400)
4. Mast, router, concrete base, etc ($400)
5. Total ($2600)

So I get a total of $5,000 for a standalone, hilltop, 2-way satellite access point. I'm probably forgetting some basic and fundamental issues and way off. Still, if a solar-powered Access Point (or hey, a REPEATER) could be built for something like $10/month, that would be so fine. If 50 people paid $10/month that's $500/month.

You couldn't build a business on it. But it might work as a non-profit.

-- AdamShand (Cut and past from the MailingList)

Thanks for posting it, Adam. I'm sure the figures are off but the basic concept is there. Here are more alternative energy and satellite links. Hams have lots of experience. Many power repeaters with PVs.

Someone posted a note that wind power might be more effective. Yeah. It's available 24hrs/day, too. Here's [http://www.solardyne.com/whish9ratat9.html a $1500, 900 watt windmill] from a local supplier, [http://www.solardyne.com/ Solodyne].

Here are some solar and alternative energy links:

[http://www.pvpower.com/pvsites.html PV Websites][http://www.rvsolarelectric.com/inform.htm Solar How To][http://www.homepower.com Home Power Magazine][http://www.solaraccess.com/news Solar Access News][http://www.solardyne.com SolarDyne in Portland][http://www.electricbike.com Electric Bikes] [http://www.electricvehiclesnw.com/main/lafree.htm $1000 LaFree Bike] [http://www.denalicycles.com/FAQpage.htm Denali Bike] [http://www.homestead.com/ne4s Imperial Cruiser with 30 foot mast] [http://www.aprs.net Dynamic Vehicle Tracking][http://www.electrifyingtimes.com Electrifying Times Magazine][http://evworld.com/index.cfm EV World Magazine][http://www.ovonic.com/enstor.html NiMH Batteries][http://www.bpsolar.com BP Solar] [http://www.siemenssolar.com Siemens Solar in Vancouver][http://ovonic.com/unitedsolar/productcatalog.html Uni-Solar] [http://via-sat.com/intl.htm ViaSat Solar] [http://www.travelbyroad.net/articles/lel02.html RV Article] [http://www.packetradio.com/solar.htm Packet Radio Repeater] [http://www.mhtx.com Fuel Cell Bike] [http://www.hfcletter.com Fuel Cell Letter] [http://www.f-cellsnetwork.com/cgi-bin/templates/99780714079022216796700003/document.html?topic=127&document=5205 Fuel Cell Links] [http://www.nrel.gov NREL]

Here are some 2-way consumer satellite links

[http://www.Starband.com Starband] Official Site [http://www.Starbandusers.com Starband Users Group] Great resource[http://www.DirecPC.com DirecPC] Now called Direct Way[http://www.hns.com/direcway/intro.htm DirecWay] Competition to Starband [http://www.Wildblue.com Wildblue] Coming next year with Spotbeams and 400K up [http://www.Spaceways.com Hughes Spaceways] Coming 2003 with 1.5Mbps and up [http://www.astrolink.com/services/index.html TRW AstroLink] Coming 2003 with 1.5Mbps and up [http://www.ibeam.com iBeam] U/O has uplink and downlinks statewide, national streaming provider for education

[http://www.iblast.com/faq.php3 iBlast] Broadcasters attempt to datacast [http://www.edgeucast.com:81/edgeucast/FAQ.jsp Hughes EdgeUcast] Marketing group for DirecPC[http://www.panamsat.com/media/pressview.asp?article=1160 Panamsat NET/36] Streaming content provider for Qwest and AT&T DSL/CableModems [http://www.pgtv.com/default.asp?flash=true Pegasus] FCC recently approved their spot beam satellites [http://www.cidera.com Cidera] Umm, forgot[http://www.netsatx.net/about/index.html NetSat] Don't know if they're still around [http://www.ico.com/system/index.htm New ICO] Craig's medium orbit answer to Teledesic [http://www.microspace.com/index2.html MicroSpace] Roll your own[http://www.orblynx.com/ OrbLynx] Forgot the details [http://www.tachyon.net Tachyon] VSAT for businesses ($500/mo) [http://www.teledesic.com/tech/tech.htm Teledesic] Craig's orbiting tax writeoff

From a post to the MailingList by SamChurchill (in part forwarded from the OpenAp list):

Anyway, I was thinking about the Bridge bridge. A DSL phone line under the Morrison Bridge feeds repeaters located on the Hawthorne and Broadway. Maybe use 802.11g for 11/54mbps.

A Linux Laptop supplies DHCP to the local node and repeaters at the distant bridges. The bridge nodes could be solar powered and since the nighttime traffic isn't much it wouldn't need to be 24/7. So this is from the OpenAp board:

• http://lists.instant802.com/pipermail/openap-dev/2002-January/000137.html

Is the SMC2655W a good candidate for a port of OpenAP? Considering I have more than a few of these deployed, I would love to be able to use them as repeaters and form a larger WAN.

Currently, the network consists of:

One point of origin, a 3mbit DSL connected to a Linux PC. The Linux PC provides a DHCP server, as well as SECIP services. The server is connected to an SMC2655W MiniAP.

Spaced approximately 1/4 mile away from the point of origin, are three Orinoco AP units that act as wireless network extenders/repeaters. I have not found any cheap AP units that can act as repeaters with 802.11b other than these at this point.

The network covers an area about two miles in diameter, with an approximate data rate of 1-2 megabits at the edge of the range.

I would love to be able to deploy the SMC2655W units as repeaters, however the firmware provided with these units is <VERY> limited. No monitoring or status, no support for a DHCP server, and the MAC address filter has room for only 10 entries. Running OpenAP on these small units would be a definite blessing, for the repeater support.

A medium sized lead/acid gel cell, a small solar panel, a good antenna, and a nicely sealed project box with just the motherboard of the SMC2655W would be an ideal solution. These MiniAP's are extremely cheap.

Martin

{{{> I am just contemplating the idea of solar powered repeaters > in sealed plastic containers that could just be littered on rooftops > of buildings to provide extended outdoor coverage on sunny days or just > thrown on the ground for temporary outdoor events.}}}

I have a solar powered repeater project. It uses Linksys (Atmel) access points (2) because they have very low power consumption (2W typ) --- all 3.3v design.

{{{> The Fry's in Sunnyvale now has a shelf where they sell > a variety of solar panels for about $8 per claimed > watt in direct sunlight, if I recall correctly.}}}

No chance! You need to remember that the sun don't always shine And solar panels are rated for full, direct, bright sunlight, so they often don't produce their rated power even in daylight.

At my location, the latitude is 46 degrees and there can be days of cloud in winter, so I have two 110W panels and two 110Ah batteries. I'd be surprised if it were possible to get away with significantly smaller arrays and batteries even in a low latitude more sunny place.

BTW, that Fry's now carries large PV arrays (Siemens), I think up to 50W. You can also buy these things online for a lower price if you shop around.

Why couldn't a 12 Volt, 40Watt Panel http://www.xprt.net/~hightech/solar.htm $200, power a 2amp OpenAP?

• http://www.homepower.com/

• http://www.solarsolar.com/

• http://solarsurplus.com/

• http://www.remoteaudio.com/ztap.htm

• http://www.solardyne.com/solpowpaccom.html

• http://www.solar4power.com/solar-power-basics.html

• http://www.siemenssolar.com/

• http://www.ovonic.com/

• http://www.packetradio.com/solar.htm

• http://www.solarcell.net/the_solar_cell_company_043.htm

• http://www.solareco.com/articles/article.cfm?id=121

• http://www.pvpower.com/pvsites.html

• http://www.solaraccess.com/news/

• http://www.norsonic.com/web_pages/env_enclosures.html

• http://www.pelican.com/product/cases/

The IBM DC adaptor can run off 12V DC. A deep cycle marine battery, runs a laptop. Assuming a 5A drain on the battery from the adaptor, you should have roughly a 20 hour life on a 110AH battery.

• http://zurich.ai.mit.edu/hypermail/thinkpad/1999-09/0463.html

Four Semiens M55 Solar Panels connected in Parallel. Each Panel Produces 55 watts of 12 volt electricity at 3.5 amperage. Connected in Parallel, the four panels produce a maximum electrical charging output of 12 volts at 14 amps. If on an average of only four hours of direct sunlight per day, this will give us approximately 56 amp hours of battery charge daily.

• http://www.polkcounty.org/ham/repeater.htm

[CategoryHardware]