If you had $1500 to buy a PV system...

System

PV Newbie here... I'm a technical guy, but nervous about the state of our economy of late and dont feel like I have a whole lot of time to do the necessary homework and due diligence for researching ideal designs and good deals.

I live in Seattle WA, the land of the rusty people... we can go months without a day of direct sunlight and I really haven't seen much online about the effeciency of PV generation in such weather conditions or which composition of PV material is optimal.

So I'd be curious to invite the experts on here (of which it appears there are many) to come up with a reccomendation of pieces parts for a solution in the $1000 category. To include batteries, panels, controllers, etc.

The target load would be the best you can get for the money. Sustaining minimal household operations in an urban area for an extended grid-down period of time.

Would love to see what folks can come up with...
Cheers!
-Greg

icarus

Re: If you had $1500 to buy a PV system...

With all due respect,,,If you are trying to save money to help with the current energy/financial crisis, I suggest that you spend your ~$1500 on conservation. After that spend some more on conservation, and finally, spend some more on conservation!

In all seriousness, if you haven't done EVERYTHING to reduce consumption, then you are throwing your RE $$ away. The next thought would be solar hot water. I know from experience that solar hot water works quite well even in the PNW, (net/net year 'round).

Other than that, consider reading and understand all that you can on the subject and try to avoid the "ready, fire aim syndrome"

Tony

wxh3

Re: If you had $1500 to buy a PV system...

This summer I installed a small standalone backup system. I live in a suburban neighborhood and the panels are in my backyard. I am running the cables through a hole my wall to a room that contains the rest of the system. I power small loads 24x7 with it and it serves as a small backup in case of power failures.

This is what I got and roughly what I paid including shipping. (My memory may be slightly incorrect on some of these.)

IronRidge ground mount for two panels $100
2x135W 12V Kyocera panels $1400
MorningStar MPPT controller w/ RTS $250
2x110AH AGM batteries $370
Samlex 300W 24V Inverter $170
Wiring, fuses, ground rod, clamp, plastic battery box, misc. ~$100

I am running the panels and batteries in series for a 24V system. I also got a 2nd inverter (250W Exceltech that I also have connected in parallel but is normally off) that I am excluding in the pricing.

Thus I paid roughly $2400 for this system. I should be able to get a 30% tax credit, so in true cost will be around $1700. I am not an expert and can't say that the particular components I bought are better or worse than others. I am generally happy with everything and the way the system is running.

Will

BB.

Re: If you had $1500 to buy a PV system...

You can easily use this link:

http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version1/

To calculate how much power a PV system will generate (including "average" weather conditions)...

For an off grid system, use 0.52 as the derating factor (assumes typical worse case losses for flooded cell batteries and AC inverter losses). Also, the program accepts 1kW of panels as the minimum number--If, for example you only want 100 watts of panels, multiply the results by 100watts/1000watt (1/10) for your system size...

From the program, in the summer you could get 70-80+ kWHours per month from 1,000 watts of panels (~$10,000 system)... During the "dark" of winter, 16-20 kWhrs per month.

In my humble opinion, such a system (emergency off-grid system--especially in Seattle) is a pure waste of money.

I am a conservationist (as in conservative) rather than a pure green type person... For emergency planning--I keep reffering people back to this old saw... you can live 3 minutes without air, 3 days without water, and 3 weeks without food... And to add to that, you can "survive" just fine with no electricity.

Water, food, fuel to cook (and sterilize not serialize), and security should be your first priorities. Conservation/insulation will help preserve resources.

If you want/need electricity--you have to get to basics... For a radio--hand crank/solar works just fine. Lighting, candles, fuel lantern, LED flashlights (and a battery supply). If you need short term electricity--get a Honda eu2000i generator and 28 gallons of stored fuel (stabilizer added--change once per year--and perhaps a siphon for your car's tank) and you can run a fridge/freezer/microwave/few CFL lights for two weeks ($900 for the generator, $120 for fuel)... By then you will have a good idea if you can continue to shelter in place, or need to bug-out (extra fuel would help here--don't use it all up in the generator).

Otherwise, plan like you are on an extended camping trip... Water storage, water filtering, dried/simple shelf stable foods, lots of plastic bags and toilet paper, etc...

Even a 1kW off-grid solar system in Seattle is not capable of running your household fridge during the winter... (You might get by with a converted chest freezer into a fridge--threads elsewhere here--but where will you get the fresh food to even put in the fridge?).

Anyway... My 2 cents worth. Your thoughts?

-Bill

Moe

Re: If you had $1500 to buy a PV system...

I'd spend it on much more important things, unless I already had them covered. If you're concerned with surviving an extended grid outage, your priorities should be:

Obtaining sufficient water from rainwater and condensation capture, or a spring or well.

Heating some of that water for distillation, pasteurization, drinking, cooking, and bathing.

Obtaining sufficient food (from foraging, hunting, gardening).

Heating some of that food for cooking and storage.

Providing for long-term storage of water and food without refrigeration (drying, canning, smoking, root cellars).

Obtaining sufficient shelter from the weather, including heating and cooling.

Defending all of the above as well as yourself and your family.

Managing your own sewage.

None of these require electricity, although for some things it may be more convenient. All of them combined can be done for less than your $1,000, much less $1,500. You needn't pay huge prices for special, new "eco," "green," "survival" versions.

However, NONE OF THEM can be done well enough to survive on without hands-on PRACTICE before they're needed. And you'll soon find how extremely valuable conservation really is.

BB.

Re: If you had $1500 to buy a PV system...

Here is a short article asking the question if survival preparation is going mainstream:

But now that seems to have changed. As I noted on my weblog last week, both Eddie Bauer and Target are selling survival kits, and a reader emailed to note that survival preparation has gone even more mainstream:

You know survival kits are mainstream when Costco is selling them. And last weekend at my local Costco, in the food section, there was a front of the aisle display of survival food buckets. They were going for $110 and had about 275 servings of freeze dried vegetarian meals

....
The federal and state governments have been pushing this, too. The Department of Homeland Security -- see its www.ready.gov site -- is pushing survival kits, (there's even a special preparedness page for kids, complete with fuzzy -- but prepared --cartoon animals) and so are many states. My brother recently got a mailing from the State of Ohio telling him to have a month's worth of food put away, in case of avian flu And the government is pushing Community Emergency Response Team training. (September was National Preparedness Month). Most such things wind up being ignored, of course, but enough people pay attention to make a difference.

Just to note--I am not at all convinced that the "Costco" survival buckets are much use as emergency food... A year or two ago, they had another vendor that claimed XX months of food in the bucket... But if you added all the calories up--and divided it out--it was for a few hundred calories per day...

Basically, you need about 12 calories per lb of body weight per day to maintain your body weight (not including heavy work, cold weather, or other situations which increase your body's need for calories)... So, a 150 lb person would need 1,800 calories per day just to maintain weight.

Plus, the first emergency bucket from Costco was all based on non-dairy creamer for "food value"--pretty much the rest of the ingredients where for flavor and texture.

In the end, a pantry with shelf stable food that you normally eat (canned foods, dried foods, flour, pastas, and such) that you natural cycle through (to keep fresh) would be a better start.

-Bill

icarus

Re: If you had $1500 to buy a PV system...

Perhaps we should all take a deep breath in these times and not panic!
Good planning is fine, but panic only leads to more,,,panic!

Tony

wxh3

Re: If you had $1500 to buy a PV system...

I installed my very small system more as a learning experience for me than anything else. I don't have any illusions that it will ever come close to "paying off" or that it will be able to power anything more than small electric items. Yes, maybe it is a complete waste of money. I still like the fact that I have at small off-grid backup power supply in the case of a power outage and that a small amount of my regular electricity usage is coming from solar. (I know it ain't much...maybe 3% in non-A/C months.)

I certainly wouldn't have done it if I was very tight on money.

System2

Re: If you had $1500 to buy a PV system...

Thanks for all the great advice so far.

I should clarify, I have been in uber-preparedness mode for quite some time having seen the writing on the walls more than a year ago; it's just all happening a little faster than I hoped. And global crisis aside; I suspect the PNW may be in for a wild Winter as we've already had our first decent snow-fall in the passes (unusual for October)... backup power never hurts.

I've got my water purification, my 6 month+ food reserve, guns, ammo, seeds, tools, genset, reserve fuel, med-kits, emergency training, plans, maps, boards, nails, tarps, the makings of a BOV... of course there is always room to improve on any of these areas so what I'm looking for in terms of Solar system is effectively icing on the cake.

I do appreciate all of the non-solar-centric advice, but I would be interested to hear more about brands, makes, models, AND DEALS for gear that folks might reccomend for an 80 watt system (or better if budget and\or scalability permit). Any references you can point me to for effecient panels in non-direct sunlight would be appreciated.

Thanks again,
Greg

System2

Re: If you had $1500 to buy a PV system...

BTW: For those of you who are passionate about prparedness; and could use some great guidance on where to start and how to prioritize... I highly reccomend getting acquainted with the survivalblog forums.
www.survivalblog.com - It's worth your time...

Cheers,
-Greg

BB.

Re: If you had $1500 to buy a PV system...

Regarding solar panels... They all need direct sunlight--their output is proportional to the amount of energy falling on the panel... With shade/fog/clouds, you will get very reduced output--no way around that.

For panels, any good quality mono or poly-crystalline panels will work fine for your application. I would avoid flexible panels (like Unisolar) unless you have a specific problem with "falling rock" or need portability (big glass panels are "easy" to break). Buy panels on $$$/watt (typically ~$3.50-$5.00 per watt, not including shipping+insurance--which can be substantial for a small shipment).

Solar controller wise, if you are near 200 watts of solar panels for a 12 volt battery system or 400 watts for a 24 volt system, the Morning Star MPPT is hard to beat. For smaller systems, anything out of the BlueSky or smaller Morning Star line would be fine.

Remember that Panels + Controllers sort of have to "match" for best efficiency... Smaller panels (100 watts or less) are available in "12 volt" sizes (really around 17 volts Vmp) to match with any PWM/MPPT controller.

Larger panels (typically 100 watts or larger) are "high" voltage panels and may work efficienty with a PWM controller on a "24 volt battery bank"--but not on a 12 volt bank with PWM.

For "high voltage" panels, you usually want a MPPT type charge controller that can efficiently "down converter" from panel voltage to battery voltage... Look around, and if you have questions, just ask. It is confusuing the first few times through a paper design for your system.

Battery wise, buy some "golf cart" batteries for your first system... If taken care of--they will last 5-7 years... If, however, you make the typical newbee mistakes--they will be killed in three years or less (under/over charging, over discharging, not keeping water levels up, adding tap water, not cleaning up acid spills, etc.)...

Inverter wise--I would suggest that you get a True Sine Wave inverter if you can justify the costs... They are more efficient overall and work much better with sensitive equipment (radio, TV, electronics, refrigerator motors, etc.). A MSW (Modified Sine/Square Wave) inverter will work OK with 80-90% of the AC equipment out there--but you will not know until you try each piece. For a small inverter, the Morning Star TSW 300 watt unit is really nice... You could use the "small" 300 watt TSW for your "good loads"... And always purchase a big 1,000 watt cheapy for running a few emergency lights and tools.

Regarding other supplies... You can look at "water saver battery caps", hydrometer, Kill-A-Watt meter (to measure your AC loads) and Battery Monitors.

A battery monitor may be too expensive for your small setup--but I believe they are the best tool to watch your battery bank and to ensure that you are properly charging/discharging it. And, a battery monitor is pretty much required if you have sealed AGM type batteries (since you cannot use a hydrometer to measure charge levels). Look at the Trimetric for low cost... And the Xantrex for high end meters.

-Bill

System2

Re: If you had $1500 to buy a PV system...

Bill... this is an excellent breakdown and pretty much exactly what I was looking for. Thank you for all the great info.

-Greg

mike95490

Re: If you had $1500 to buy a PV system...

Greg357 wrote: »

I live in Seattle .... we can go months without a day of direct sunlight and I really haven't seen much online about the effeciency of PV generation in such weather conditions or which composition of PV material is optimal.

PV panels need a LOT of bright light to work. On a clear day, with a little haze, the will still work, but overcast or clouds, and they do nothing. Seattle is not a good solar PV location, IMHO.

BB.

Re: If you had $1500 to buy a PV system...

If you set your expectations--solar can work for you in Seattle... Again, using the solar link from my earlier post:

http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version1/

Note, the solar calculator above uses 1 kW as minimum solar panel size... You can get smaller panel ratings by just using the fraction of (for example if your panel rating is 200 watts) 200watts/1,000watts. Also, for Grid Tied systems, I would set the derating factor to 0.52 for overall system losses (yes, you need about 2x the number of solar panels to make up for system losses).

Lastly, if you want, you can look at the PDF files for various states/cities... There is a nice little solar graph for each city that shows how variable solar is over ~10 years (some places, will vary by a factor of 2x year to year--depending on weather patterns).

http://rredc.nrel.gov/solar/pubs/redbook/

You can get decent power from your solar panels (3-5+ hours of sun per day) for 9 months of the year in Seattle... It is only during November, December, and January when you are down in the 1.2 to 1.7 hours per day of sun (average).

-Bill

icarus

Re: If you had $1500 to buy a PV system...

Thew following is a real time display of a 2kw installation in Bellingham. You can see how it does on a hourly, daily, weekly, monthly, yearly as well as life time. The system, in real world conditions generates ~ 1800kwhs ~ $200 worth of electricity. It is pretty illustrative to see real data with a real system in real time. Pretty eye opening. A system that costs X generating Y.

I do know that Seattle has more grey days in the winter than Bellingham, as the grey hangs between the Cascades and the Olympics. IMHO, PV solar is a big up hill climb on the coast, but solar (pre-heat) hot water works pretty well.

Tony