anyone in north houston / spring?

Row1Row1 Registered Users Posts: 10
hi - I will be new to solar stuff, once I get started.
I want to develop a modest solar system to power a few things when the next hurricane hits us, and puts the power out.
So, I am thinking: recharge rechargeable batteries, recharge cell phones, run a small radio, run a laptop, maybe run a box fan at night, maybe run a low-power tv, like a 7inch portable lcd tv.

It has been a few decades since I took 'electricity' class in middle school. I do remember amps volts ohms were taught, but have forgotten all that. but at least I kind of know what resistors do, also diodes, capacitors, voltmeter, I know that longer runs of wire eat up your power, etc.

I want to assemble a modest solar kit to use now for these things, so I am ready when the power goes out. I have heard lots of problems with shipping solar panels, so my guess is to try to buy locally. but I don't know where, or what kind.

Also - I want to get at least one AGM battery, but again, these are heavy, so shipping is high, and it might be better to buy locally to save on shipping.

I guess my budget is several hundred dollars.

We get lots of sun here during hurricane season. If it is too cloudy to generate electricity, we are basically happy for the break from the sunny heat!

It would be good to have some local advice. Let me know if you would be itnerested in helping me get a modest system going to provide power for this type of situation. Thanks! ---Row1


  • BB.BB. Super Moderators, Administrators Posts: 33,313 admin
    Re: anyone in north houston / spring?


    Welcome to the forum (we probably don't say this enough to new posters/readers--we just want to jump in and help).

    First, here is a good thread for you to read through... Starts pretty much from ground zero (new to solar user) through detailed discussions of major points of designing and building a small off-grid battery system.

    Just an FYI--building a small emergency use solar powered system is not usually cost effective (a solar panel generates power 365 days a year--so using it only 2 weeks per year is not very $$$ efficient, and trying to use a small off-grid system to power your home office/bedroom is not very $$$ efficient either--off grid power typically costs $1-$2+ per kWhr for a system used year round. Generator power may cost you $1 per kWhr--but you only run the genset when you need it)... But many people will do it anyway for the knowledge and/or to fill a special need for them (like long power outages due to storms and such).

    Usually, the most cost effective emergency power is a generator. I really like the Honda eu2000i--gives you about 15 amps @ 120 volts (1,600 watts continuous), and is very quite / fuel efficient down to the 400 watt level or below (~15 hours on 1.1 gallons of fuel).

    Much better than the 5kW "noise" makers that will drink 4-8 gallons of fuel a day.

    If you have propane or natural gas available--some genset that runs on those would be nice too. Generally, I recommend people not get a "large" whole house capable genset as they drink the fuel when running small loads (a 10kW typical emergency system will take ~1 gallon of fuel per hour--or equivalent propane/natural gas--for loads of 5kW or less). And diesels should be operated at ~50%+ load or they tend to carbon up.

    If the Honda eu2000i does not meet your needs (say you need A/C)--you can also look for a used Onan or equivalent RV genset... Frequently they are mutli-fuel, quiet and include electric start.


    PS: You will find that solar RE is not cheap... A couple hundred dollars will probably power a small radio/light/tv for a few hours per day.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: anyone in north houston / spring?

    the loads you cite are low power consuming except for the fan and even low power items can consume much power over time. this means either making your system large enough to handle the loads every day or sacrifice some of that power usage. note that you always forget about other things like a light or powering your frig as that food will go bad. you need to re-evaluate your needs per day. this will be in watt hours or it could be in amp hours if you stay with 12vdc. this will determine the size of the battery(s) needed as well for your total loads should not exceed 1/2 of the battery capacity. in other words for example if your loads are 51ah per day the battery should have at least 102ah capacity. next you need to size up the pvs to charge that battery or batteries. going by the example of 51ah this must be replaced and will most likely be over 5 or 6 hours of full sun in a day. going by 5 hrs this is 10.2a being delivered from pv(s). you may wish to add about 30% more for charge losses, resistive losses, etc. 1.3x10.2=13.26a needed from pv.
    this is all of course an example and your needs may be more or less, but know that this is expensive for backup only during a hurricane. you may wish to find use of such a thing for normalized useages, but during a prolonged period of no power this is priceless. a generator is also expensive for emergency only uses and will require and run out of fuel, plus if the gas station is also out of power, which would most likerly be the case, they can't operate the pumps to replenish your gas supply unless they too use a generator. even if they have a generator and can run it to pump gas, they all have their own homes they would be worried about and not so much making a buck. it still may be a good thing to have an inverter type generator on hand, but gas does not store well. an option here may be to hand pump some from your car if you have one. that keeps as a fresh gas supply. you also don't want to leave gas in the generator.
    it all depends on how far you want to go with it no matter how you do it. you might do a search in the forum on this as the topic has come up a few times.
  • Row1Row1 Registered Users Posts: 10
    Re: anyone in north houston / spring?

    thanks for the input so far.
    yes, i plan to use whatever solar stuff year-round, for recharging cell phones, running laptop, and other little things like that. I understand that it will not be cost-effective compared to grid electricity rates, but it is partly for the learning experience plus partly to better handle power outage of a few days here and there.

    Many of my neighbors have generators. i want to try to avoid the mad max world of searching for gasoline. after hurricane ike, this was no fun. i got up at 4am three days in a row to fill up each of 3 cars (mine plus family members) once the gas stations were getting gas again. my neighbors with generators had to keep an eye on the gas gauge. plus the noise is really bothersome.

    the main need is for info: if I know how long power will be out, I can judge whether to sit tight, or use my limited gasoline to drive to wherever I can get internet on the solar-powered laptop, and make a hotel reservation. etc. If I can communicate with family, etc., then I can figure out where my volunteer help might be most needed, etc.

    Thanks for the info so far!
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: anyone in north houston / spring?

    info on how long an outage may be, may be harder to come by than you think. laptops can be operated by 12vdc as many have car adapters available and that makes it very compatible for solar. the thing about solar is that if the sun comes out the next day you get more power coming to you and it will do so every day that the sun is out. as i said, if you know your loads and the times needed you can size up a system for yourself. it is difficult for us to determine your power requirements needed in order to size up a solar system as this is something you need to do.
    do the search here too as there are many aspects involved that you can find in other threads like the survivability of the pvs in a hurricane. they make great sails for hurricanes and even if they stay, flying debris can destroy them just as well.
  • Row1Row1 Registered Users Posts: 10
    Re: anyone in north houston / spring?

    good point about how the winds will carry anything. at least i hav a garage and can quickly duck solar panels in there, next to the gas grill.
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