Solar quote - review

[fastpoke]

Hello,

I'm looking to get some opinions from the group on some quotes I have received for a solar system for our cabin. A bit of background is, we use this on weekends and long weekends, typically go out every 3 -5 weeks or so. The longest we stay out there is possibly 5 days over Christmas and maybe a week in the summer. I'm hoping to attach the quotes for review, I went to 3 companies and received 4 quotes. Also my estimated usage is (o the low end) 9kw for 4 days or 34kw for 4 days on the high end. Options are appreciated.

thanks Mody

Quote # 1
Off Grid System
570 watt 24Vdc Magnum System
Category Description
Solar 3 - 190 watt Astronogy Solar Panels (570 watts)
FM60 Solar Charge Controller
Battery Temp Sensor
Midnite Solar Combiner Box (6 Breaker size)
MC Connectors (3)
Breakers (3)
Magnum Inverter Magnum 4000w 24Vdc 120/240 Inverter (120/240Vac)
DC Disconnect and 3 Way Bypass
105 amp DC Battery Charger
Remote Monitor
2 - 10' 4/0 cable pair
Batteries Powersafe V AGM Sealed Maintenace Free
8 - 12Vdc 200amp/24hr dischargeAGM Batteries
4- 24Vdc banks 200amps total 800amps (19.2 Kw)
Total $ 8,283.00

Quote#2 - 34 KW usgae
230 Watt Solar Panels (5 Kilowatt System) 22 325.00 7,150.00
22 Panel Mounting Kit 1 2,000.00 2,000.00
5000 Watt Pure Sine Inverter 1 920.00 920.00
7200 Watt SWD Charge Controller 1 695.00 695.00
Fuses/Breakers/Panel 1 400.00 400.00
Trojan T-105-RE Batteries 24 195.00 4,680.00
6500 Watt Gas Generator 1 799.00 799.00
Power Switch Over Relay 1 300.00 300.00
100 Amp Battery Charger 1 995.00 995.00
0.00 0.00
Installation 1 3,000.00 3,000.00
Travel Charge 1 600.00 600.00
GST on sales 5.00% 1,076.95
$22,615.95

Quote#3 - 9KW usage
230 Watt Solar Panels (5 Kilowatt System) 16 325.00 5,200.00
22 Panel Mounting Kit 1 1,600.00 1,600.00
5000 Watt Pure Sine Inverter 1 920.00 920.00
7200 Watt SWD Charge Controller 1 695.00 695.00
Fuses/Breakers/Panel 1 400.00 400.00
Trojan T-105-RE Batteries 16 195.00 3,120.00
5500 Watt Gas Generator 1 899.00 899.00
Power Switch Over Relay 1 300.00 300.00
100 Amp Battery Charger 1 995.00 995.00
0.00 0.00
Installation 1 3,000.00 3,000.00
Travel Charge 1 600.00 600.00
GST on sales 5.00% 886.45
$18,615.45

Quote #4
Hi Mody,
 
I've made a few assumptions and they are below with the results:
 
Assumptions:
Modules will be installed on pole at 65 degrees from horizontal
Shading is zero
Weather data is Golden, BC
IMPORTANT! I assumed you will have a 3 day battery backup which is about as small as I'd recommend. This means after zero sun for 3 days with standard load, you will have no energy available from the batteries. This can be increased by making the battery bank larger. A backup genset will allow you to use this small battery bank to get you through long periods of more than 3 days with zero sun.
I've assumed sealed maintenance free batteries that come with their own enclosure. A sample spec sheet is attached.
All dollar amounts below are ESTIMATES
 
Both systems would likely use the same inverter and charge controller as it is sized based on the maximum load you'd have running at one time. A good option is the Xantrex 6048 (specs attached) with a 60A charge controller. This comes with an AC distribution panel so that can be used for all the breakers in the cabin. Cost is about $9,000. If you want something smaller and simpler we can do that and save some money, but you'd need to install a regular breaker panel in the cabin.
 
Option #1: Large System
Average daily load: 4640 Whr (note that 2/3 of this is from toilet and fans)
Battery bank required: 725 Ahr at 48Volts = 34.8kWh. Cost about $10,000
Solar required: 2500 watts. Cost with rack (NOT including pole or concrete for pole) is about $8,000
Total cost, NOT installed is about $27,000+tax
 
Option #2: Small System
Average daily load: 1391 Whr
Battery bank required: 220 Ahr at 48Volts = 10.6kWh. Cost about $3,000
Solar required: 740 watts. Cost with rack (NOT including pole or concrete for pole) is about $3,000
Total cost, NOT installed is about $15,000+tax
 
Install cost is not included in either of the above but can be if required.
 

[alex trent]

High priced is a polite way of putting it.

OK, if you absolutely, positively do not want to run a genet you will need to pay a price in batteries and panels.   But for you described use and in that area with the sun you have, this still is high.

If you are willing to compromise and run the genset a couple of hours a day (or maybe even less)
you can get by with half the batteries they propose and in some of the quotes fewer panels.

I did not do any real calculations, this is based on my system which cost $3,000 including a genset...and now adding solar to it will be another $1,500...so say 4.5K and I am at the cabin every day and run a fridge.

[OlJarhead]

Are those prices Canadian? 

Seems pretty high but perhaps it's because I'm in the US?  My 615watt system was less then half what you've shown for a 570 system.

[MountainDon]

Quick comment, more later most likely as time permits

#2 and #3 do not list brand for inverter. I don't like that as who knows what it is; cheap import?  Never heard of SWD charge controller, but maybe that's just me

The last one mentions Golden, BC, so those are likely all Canadian dollar quotes?

The Xantrex 6048 is good. (last quotes). Is the CC also a Xantrex?   Make/model of batteries?

The Magnum inverter that does 120/240 is good too. Redoverfarm has one, BTW. Do you need the 240 for a pump.

#1 and #2 mention a battery charger.  Any good inverter should be an inverter / charger. No need for an extra charger as the generator would use the charger built into the inverter / charger.


... gotta run and go do some errands...

[MountainDon]

Before going much further you really need to try and nail down the capacity required a little better. That is a wide range and, IMO, you may not get detailed and serious cost estimates because of that. It seemed daunting to me several years ago and I was not being honest with myself for the first few estimates. They were too low. Then leave some room for the use to grow, ours did by at least 25% from my final honest estimate.

That is a huge range; it would seem the potential consumption has to be really worked on before selecting components.


What is the weather like? That is if you go to the cabin for a weekend is it likley to be mostly sunny or mostly cloudy. I like having a storage based on providing three days of autonomy coupled with a battery bank sized to keep going below 75% discharge when that happens. That leaves plenty of room for low rates of discharge when the weather is mostly sunny. In NM we are mostly sunny so that is easy to accomplish. If it was mostly cloudy then I'd want more battery capacity.


It is possible, and IMO desirable, to not need a generator in an off grid system. They do have a place but I personally do mnot like them. They absorb time in maintenance and they use fuel which much be transported and stored properly. If not stored properly and not used once in a while theyre is a chance that when needed they won't work. Propane fueled generators avoid the problems associated with liquid fuels and reduce maintenance. If you've spent any time looking around this site on this subject you will know I do not like generators. Just my opinion, just like others have the opoinion that daily use is fine.

On the other hand with use being of relative short duration and weeks apart it may be advantageous to go towards the small end on storage (batteries) and have a generator in case it is cloudy.  Personal decision time.


Once the battery capacity is determined you can select the number and size of the panels required to recharge the batteries in the time of year with the lowest available usable sunshine.


The prices on the T105's seem high. The CDN$ and the US$ are very close to being the same right now. I can get them here for 132 to 150 US$. Trojan also drop ships batteries all over Canda and the USA. You should be able to find better pricing on them, if that's what you use in the end. There are many other choices too. I've had great experiences and low prices with TheSolar.BIZ.  It may be worth a call to check with them.

A lot of what you do, what you buy has a lot to do with your own comfort level with this. Can you install everything yourself or do you want it done and you just have to turn the key, so to speak. I'm very comfortable but I know people who are not as well as knowing people who should not touch anything electrical.   


... dinner prep calls...

[alex trent]

Canadian and USA are at equal value.  So that is not a factor.

If i may suggest, this may be because for the incidental use described for the cabin, this is way "overpowered".  In seven months of the year, it is cool enough that even a reefer is not necessary.

And in the other times, I assume that you will bring food with you, so the reefer just operates when you are there, and not all that much load for these short trips as frozen cans of beer, and stuff, really reduce the reefer load.

What else id there for a big load in a weekend cabin?  If you have some heavy duty pumping chores, a hour on the genset can do that one a weekend (as it pulls the reefer down to 35 degrees and shoots some juice into the batteries.

IMO these kind of setup requirements  are what kill SP.

[alex trent]

Mtn Don said....

"It is possible, and IMO desirable, to not need a generator in an off grid system. They do have a place but I personally do mnot like them"

I do not like them neither.  Although I have one.  Someday I will not...hopefully.  But right now lets me save a ton of money and while building and using a lot of power tools at he sam time provide convienince.


Fo him, if it can save 5K, might be worth an hour or two of noise a day.


Mine starts first pull all the time...a day apart or two weeks, If not i am sure I might not be so generator friendly. Yamaha 2600..200 hours and have not changed the plugs.

[fastpoke]

Thanks for the input guys, much appreciated. Even though our currencies are at par, we tend to pay more up here in the "Great White North".

Option #1 the inverter has the charger built in to it.
Option #2 are Chinese imports the they " modify" to make improvements
Option #3 The CC is also a Xantrex
Below are the 2 load analysis that I completed using a chart I found online.

ELECTRIC LOAD ANALYSIS WORKSHEET   #1               
ITEM   VOLTS   AMPS              WATTS                       DAILY USE (HRS)                DAYS/WEEK        WATT-HRS/WEEK
Bedroom lights (led) x 4   120      12.5                              4                                    4                                  200
Living/kitchen (LED) x 4   120      12.5                                  8                               4                               1600
Stereo   120                              35                              16                                       4                                 2240
TV          120      150                                                          4                                   4                         2400
Laptop   120      50                                                          2                                   4                         400
toilet   120                           150                                 12                                 7                       12600
   120               
toaster (Optional)   120      6.6   792                               0.16                               4                             506
kettle (optional)   120             800                             0.25                                    4                           800
microwave   120                   900                          0.25                                       4                                   900
drill   120                                  750                             0.25                             1                                 187.5
vacum   120   5                        600                              0.5                                      1                                     300
saw   120                                 1400                          0.5                                      2                                     1400
grinder   120   7.5                        900                            0.25                                  1                                   450
ceiling fan x 2   120                 100                               24                            4                                     9600
table fan   120                          20                               4                                   4                                      320
                  
All AC
TOTAL                  33, 903.5
                  
ELECTRIC LOAD ANALYSIS WORKSHEET   #2               
ITEM   VOLTS   AMPS   WATTS   DAILY USE (HRS)   DAYS/WEEK   WATT-HRS/WEEK
Bedroom lights (led) x 4   120      12.5   4   4   200
Living/kitchen (LED) x 4   120      12.5   8   4   1600
Stereo   120      35   16   4   2240
TV   120      150   4   4   2400
Laptop   120      50   2   4   400      
microwave   120      900   0.25   4   900
ceiling fan x 1   120      30   24   4   2880
table fan   120      20   4   4   320
All AC         
TOTAL                  10940

Hopefully you can make some sense of the calculations. Our fridge is propane powered, but uses 12v for the igniter.

thanks, Mody

[Dave Sparks]

What are your long term goals with the property?

[UK4X4]

Any system you build is always upgradable- but is limited by what you invest in first

if you want calculated advise - you really need to make a command decision on what size you require today- but thinking of future upgrades- additions

Upgradability - adding to the system means you should look at equipment that talks to each other

ie not a chinese no name- something thats designed to be reliable and "system" compatible

if things link together it makes upgrading easier and cheaper in the long run

Both xantrex and midnight make network based equipment.

But they won't speak to each other- they are manufacturer comms systems

I have no ducks in either pond- but from my investigations - midnight systems seem slightly more expencive than xantrex

If I was buying a system today I'd start with large well respected companies- that provide support 10 years down the road

connect to each other in a networked system.

Thats charge controller/ Invertor charger -mains switch over-digital dispaly/ controller- generator start if required

panels being seperate- but again if I want to add to the system later I need compatible panels

I'd rather pay for known names with 20+ year guarantees.

Internet dealers seem to have lower prices than your local shop

But its a sell and byby scenario- you makes the decisions on what goes together
rather than the local shop that sells you what he did at Joe Blogs cabin down the road.

[UK4X4]

Alt energy store I've purchased through before although individual parts and not a complete system

Gives you some structured cost/ system size

But I'd swap the charge controller and inverter to two same supplier versions so they can talk together making adding to the system easier down the road

http://www.altestore.com/store/Packaged-Systems/Off-Grid-Residential-Systems/c567/


anothers

http://www.solarblvd.com/Solar-Panels-&-Systems-Off-Grid-Solar-Power-Systems/c1_57/index.html?osCsid=275fe7da327262d71975dbf3241f97f4

This one supplies matched equipment from one supplier and high quality panels

http://www.solar-electric.com/ofsokiforho.html