Posted by tiedyed859 on January 23, 2005, 5:31 pm
Moving to a remote area and wanting to use solar, but the dollars don't add
up...to continue our normal usage, which is 40 kWh a day average, would cost us
in the area of $40K. (Average) with state rebates, etc. we still are looking at
a payback period of longer than system life, especially batteries...cost to run
power to our new homestead is in the $10K range and average monthly bill would
be around $60/75...Add a generator for back up...same as we would have to do
with solar, so the cost of it is not included in either system...any ideas as
to how we can do solar and still be within a reasonable use/payback period?
Cutting back to less use and a smaller system is not the answer for this
particular application, Thanks
Posted by Robbie McFerren on January 23, 2005, 5:52 pm
Ok, cutting back does not mean using fewer appliances, cutting back means
using more efficient appliances and electronics. Another easy way to cut
back is to run 12 volt outlets in your house for things such as cell phones,
pdas, laptops and so on. Cutting back on the need for inverters will save
you some energy. I am under the assumption that most home PV systems are in
the 24-48 volt range and won't allow you to do that without an uneven
discharge on your battery bank.
As far as appliances are concerned, use propane gas for heating, water
heating, and cooking. Ceiling fans are avalible from speciality shops
online that operate on either 12 or 24 volts. If cooling your home with
fans is not possible or liked, solar power may not be your best bet,
otherwise go for it. If this is a dry climate an evaperative cooler may
save you from the last sentence. Energy efficient refrigerators are
avalible online from the specialty places and will take signifigantly less
electricity. TV watching may lead you to LCD or maybe plasma for screens
larger than 13 inches as CRTs are grossly inefficent. Desktop computers are
not going to work well. Home theater will be OK if you don't have a 500 or
more watt system and should be run on a True sine wave inverter as well as
TV and VCR.
Lighting is also a good Idea to shift to battery voltage, you can convert to
fluorescent at the same time. While doing this, it may be possible to wire
some rooms with only battery voltage. If you can go down to a 12 volt
system fewer devices will need to run on inverters. You can get 12 volt
coffee makers at truck stops and RV stores. Online you can get battery
voltage Microwave ovens which will really save you as far as inverters are
concerned as fewer voltage transformations take place. Be careful some
microwaves advertise 12 volt operation but include the inverter to get the
12 volt claim. The few 12 volt microwaves out there will wire directly into
your 12 volt system and will take around 60 to 80 amps. If you choose to
run a microwave off an inverter look carefully for the actual wattage it
takes from the wall socket. Example in my RV my 700 watt oven takes 950
watts from the wall.
Get creative,look on the internet for things, don't be afraid to google for
hours to find nothing.
Please forward this to anybody that says that reducing load is not possible,
it is in most cases. You just have to think.
Posted by Steve Spence on January 23, 2005, 7:56 pm
You can easily run 12vdc appliances on a 24-48 volt system with the
appropriate dc to dc converter. Wire runs have to be thick and short, as
the amps are much higher at lower voltages. We have a couple of low
voltage emergency lights, everything else runs from inverter.
Steve Spence
Dir., Green Trust
http://www.green-trust.org
Robbie McFerren wrote:
> Ok, cutting back does not mean using fewer appliances, cutting back means
> using more efficient appliances and electronics. Another easy way to cut
> back is to run 12 volt outlets in your house for things such as cell phones,
> pdas, laptops and so on. Cutting back on the need for inverters will save
> you some energy. I am under the assumption that most home PV systems are in
> the 24-48 volt range and won't allow you to do that without an uneven
> discharge on your battery bank.
> As far as appliances are concerned, use propane gas for heating, water
> heating, and cooking. Ceiling fans are avalible from speciality shops
> online that operate on either 12 or 24 volts. If cooling your home with
> fans is not possible or liked, solar power may not be your best bet,
> otherwise go for it. If this is a dry climate an evaperative cooler may
> save you from the last sentence. Energy efficient refrigerators are
> avalible online from the specialty places and will take signifigantly less
> electricity. TV watching may lead you to LCD or maybe plasma for screens
> larger than 13 inches as CRTs are grossly inefficent. Desktop computers are
> not going to work well. Home theater will be OK if you don't have a 500 or
> more watt system and should be run on a True sine wave inverter as well as
> TV and VCR.
> Lighting is also a good Idea to shift to battery voltage, you can convert to
> fluorescent at the same time. While doing this, it may be possible to wire
> some rooms with only battery voltage. If you can go down to a 12 volt
> system fewer devices will need to run on inverters. You can get 12 volt
> coffee makers at truck stops and RV stores. Online you can get battery
> voltage Microwave ovens which will really save you as far as inverters are
> concerned as fewer voltage transformations take place. Be careful some
> microwaves advertise 12 volt operation but include the inverter to get the
> 12 volt claim. The few 12 volt microwaves out there will wire directly into
> your 12 volt system and will take around 60 to 80 amps. If you choose to
> run a microwave off an inverter look carefully for the actual wattage it
> takes from the wall socket. Example in my RV my 700 watt oven takes 950
> watts from the wall.
> Get creative,look on the internet for things, don't be afraid to google for
> hours to find nothing.
>
> Please forward this to anybody that says that reducing load is not possible,
> it is in most cases. You just have to think.
>
>
Posted by Jonathan Mau on January 24, 2005, 8:34 am
Steve Spence (sspence@green-trust.org) writes:
> You can easily run 12vdc appliances on a 24-48 volt system with the
> appropriate dc to dc converter. Wire runs have to be thick and short, as
> the amps are much higher at lower voltages. We have a couple of low
> voltage emergency lights, everything else runs from inverter.
Does this make sense? DC to DC converter is an energy transformation. So
is an inverter. Is the DC-DC way sufficiently more efficient to
compensate for the wide spread easy availability and low cost of 120VAC
goods as compared to 12 volt specialty goods? Plus the hassle of having
two wiring infrastructures in the home?
Jonathan
Posted by Steve Spence on January 24, 2005, 9:05 am
Not usually, but it's an option. We don't use them ourselves. Like I
said, we have some 12vdc lighting in case the inverter or generator is
off line, but everything else is 120vac.
Steve Spence
Dir., Green Trust
http://www.green-trust.org
Contributing Editor
http://www.off-grid.net
http://www.rebelwolf.com/essn.html
Jonathan Mau wrote:
> Steve Spence (sspence@green-trust.org) writes:
>
>>You can easily run 12vdc appliances on a 24-48 volt system with the
>>appropriate dc to dc converter. Wire runs have to be thick and short, as
>>the amps are much higher at lower voltages. We have a couple of low
>>voltage emergency lights, everything else runs from inverter.
>
>
> Does this make sense? DC to DC converter is an energy transformation. So
> is an inverter. Is the DC-DC way sufficiently more efficient to
> compensate for the wide spread easy availability and low cost of 120VAC
> goods as compared to 12 volt specialty goods? Plus the hassle of having
> two wiring infrastructures in the home?
>
> Jonathan
>
XML site map
> using more efficient appliances and electronics. Another easy way to cut
> back is to run 12 volt outlets in your house for things such as cell phones,
> pdas, laptops and so on. Cutting back on the need for inverters will save
> you some energy. I am under the assumption that most home PV systems are in
> the 24-48 volt range and won't allow you to do that without an uneven
> discharge on your battery bank.
> As far as appliances are concerned, use propane gas for heating, water
> heating, and cooking. Ceiling fans are avalible from speciality shops
> online that operate on either 12 or 24 volts. If cooling your home with
> fans is not possible or liked, solar power may not be your best bet,
> otherwise go for it. If this is a dry climate an evaperative cooler may
> save you from the last sentence. Energy efficient refrigerators are
> avalible online from the specialty places and will take signifigantly less
> electricity. TV watching may lead you to LCD or maybe plasma for screens
> larger than 13 inches as CRTs are grossly inefficent. Desktop computers are
> not going to work well. Home theater will be OK if you don't have a 500 or
> more watt system and should be run on a True sine wave inverter as well as
> TV and VCR.
> Lighting is also a good Idea to shift to battery voltage, you can convert to
> fluorescent at the same time. While doing this, it may be possible to wire
> some rooms with only battery voltage. If you can go down to a 12 volt
> system fewer devices will need to run on inverters. You can get 12 volt
> coffee makers at truck stops and RV stores. Online you can get battery
> voltage Microwave ovens which will really save you as far as inverters are
> concerned as fewer voltage transformations take place. Be careful some
> microwaves advertise 12 volt operation but include the inverter to get the
> 12 volt claim. The few 12 volt microwaves out there will wire directly into
> your 12 volt system and will take around 60 to 80 amps. If you choose to
> run a microwave off an inverter look carefully for the actual wattage it
> takes from the wall socket. Example in my RV my 700 watt oven takes 950
> watts from the wall.
> Get creative,look on the internet for things, don't be afraid to google for
> hours to find nothing.
>
> Please forward this to anybody that says that reducing load is not possible,
> it is in most cases. You just have to think.
>
>