Solar powered motorhome question.

[nternal]

1) The claims made by the company are a bit magic - if you check up on both flat plate and evacuated tube type exchangers their overall efficiency is quite similar -
a) In a cold or cloudy situation the evacuated tube type are generally better
b) Evacuated tube type can produce hotter water but less volume
c) In a mild sunny climate the flat plate type win hands down

2) Their chatter about converting 92% of incidental UV is of no meaning - except to impress newbies

3) Solar for infloor radiant? I have looked at that before and have come away totally unimpressed - takes storage and many panels.

They must be having fun trying to sell their product in the land of cheap electricity - even with the rather inflated claims.

The site is dedicated to the fuzzy headed green lot that love such inane chatter.

Well it did sound a little too good to be true.

[Mike90250]

... BTW, does anyone have any thoughts on the recently developed full spectrum solar panels that are 70% efficient and, in theory, cheaply manufactured?

Vaporware and/or scam - they don't exist

[russ]

You can read the MIT and other university web sites for this kind of stuff as well.

When the product goes commercial and is actually used in other than an extremely controlled environment for a selected audience it means something - this is PR chatter probably looking for suckers for more funding. The fact they list a Cleantechnica article for PR says a lot about the company and none of it good - I firmly believe they post articles for pay.

[nternal]

You can read the MIT and other university web sites for this kind of stuff as well.

When the product goes commercial and is actually used in other than an extremely controlled environment for a selected audience it means something - this is PR chatter probably looking for suckers for more funding. The fact they list a Cleantechnica article for PR says a lot about the company and none of it good - I firmly believe they post articles for pay.

Ok... how about "cold fusion"!

[rbtrrer]

4-6-8k$ should get >adequat system but still may have to suplament with generater/grid charge based on amount of sun.


*caveats abound!!!

[Sunking]

nternal the only way you are going to get electric heat in an RV is to park it at an RV park and plug into the grid.

Lights are no problem using solar in an RV. Refrigeration is going to be a challenge but possible and will need a generator as backup. For heat and cooking you are going to need LPG.

[noone]

nternal the only way you are going to get electric heat in an RV is to park it at an RV park and plug into the grid.

Lights are no problem using solar in an RV. Refrigeration is going to be a challenge but possible and will need a generator as backup. For heat and cooking you are going to need LPG.

I know everyone says this but I actually think in SOME cases cooking is much easier with solar and 12 volts than refrigeration.

A refrigerator is running much of the time at (usually) fairly low amps. 12 volt cooking does use more amps but for a lot of things the total power used is little (20-50 watt hours for a meal for one or two). Cooking with 12 volt and LiFePo4 batteries does make sense and even with AGM batteries can be ok. Of course for cooking things that take a while, it makes a bit less sense though still may be doable.

As for heating, I wonder how one of those small low powered 12 volt heaters would go plugged directly into a solar panel? They are little more than demisters, but if you got a 120 watt heater and plugged it into a 12 volt 180 watt solar panel it may well be enough during the day for a few hours at least.

Again though for heating unless you had LOTS of battery even an almost useless 150 watt heater for 8 hours is going to need 200 amp hours of battery...doable but a waste compared to propane.

[Sunking]

I know everyone says this but I actually think in SOME cases cooking is much easier with solar and 12 volts than refrigeration.

Microwave can be done, but microwave cooked food really suks. They are great for popcorn, steaming veggies, and reheating coffee but that is about it.

[noone]

Microwave can be done, but microwave cooked food really suks. They are great for popcorn, steaming veggies, and reheating coffee but that is about it.

I use a 12 volt frypan with a small AH AGM battery (but will use a LiFePo4 motorcycle battery soon for better handling of 10 to 15 amps and more usable power for the capacity plus lighter weight) charged from a 50 watt panel. Works great for ME but then I do not cook things that take too long.

[billvon]

As for heating, I wonder how one of those small low powered 12 volt heaters would go plugged directly into a solar panel? They are little more than demisters, but if you got a 120 watt heater and plugged it into a 12 volt 180 watt solar panel it may well be enough during the day for a few hours at least.

If you are going to do that you are FAR better off just putting a skylight in. Close to 100% efficiency heating as opposed to 15%.

[Naptown]

If you are going to do that you are FAR better off just putting a skylight in. Close to 100% efficiency heating as opposed to 15%.

Until the sun goes down then a huge loss when heat is most needed.
for the most part skylights are a net loss. Too much loss vs gain during heating season and way too much gain during cooling season.

[billvon]

Until the sun goes down then a huge loss when heat is most needed.

A good double pane window will retain most of the heat. Or just block it off with a piece of styrofoam.

He was talking about heat during the day anyway. Direct solar is always better than solar PV -> electric power -> electric heat.

[Naptown]

Moveable insulation works. it's a PITA but it works.
In an RV during the winter when heat is needed however not so much. Remember the roof of an RV is generally flat so the angle of incidence is high meaning little heat and lots of loss. Summer is the reverse, although some sun control on the exterior would help. An operating light would be better to vent excess heat from the top.

[nternal]

A good double pane window will retain most of the heat. Or just block it off with a piece of styrofoam.

He was talking about heat during the day anyway. Direct solar is always better than solar PV -> electric power -> electric heat.

Actually no. I'm looking to meet minimum survival requirements and one doesn't just need to survive during the day. Clearly one needs a way to store energy for this and, even more clearly, it seems it can't really be done with current technology.

[Sunking]

it seems it can't really be done with current technology.

Sure it can the technology is over 100 years old and is pure solar power, LPG. You can store enough on a RV to last a month or two.