So here's the dealio:
So we moved into my late grandparents' old place, it's an older mobile home, electric heat, and kinda drafty. Needless to say, the electric bill was a but of a shock. Now the place belongs to my mom, and we're living here rent free, and she doesn't care if we remodel, better windows etc, but then I thought about solar.
My question, what kind of cost am I looking for for a 1200 sq. ft. mobile home? Also, where should I go to buy said solar power system?
Go!
Duke
SuperDork
1/11/12 9:17 p.m.
Unless you are completely off the grid, solar power lives and dies by the tax rebates and subsidy programs that are particular to your state. That's the first place I would look - your state's website.
Although they may not make recommendations, I would also check the US Green Building Council website for useful links.
Good luck!
Taiden
SuperDork
1/11/12 9:23 p.m.
You will save more money, with less investment, and faster with solar water or home heating. Plus you can DIY the crap outta it. That's grassroots solar energy!
JoeyM
SuperDork
1/11/12 10:32 p.m.
Duke wrote:
Unless you are completely off the grid, solar power lives and dies by the tax rebates and subsidy programs that are particular to your state. That's the first place I would look - your state's website.
...and in this economic/political climate, those subsidies may go away (i.e. buy now)
Even if you covered your entire roof with solar panels, it won't supply enough to heat unless you live in a very well insulated home in Phoenix... in the summer.
Each cell (one of those little 3x3" squares) is rated for something like 0.45W, and that's in heavy sunlight with direct angles. So it would take something like 65 panels (each with 100 cells) to run even the most efficient trailer like you talk about.
Solar is great in areas that get a lot of sun, but even in CA or NM its typically only used as a supplement - charge batteries to run the TV at night, or use it to run an attic fan.
I agree, don't use the sun to make electricity, use it to directly heat the water. Make your own panels with a bunch of 1/2" copper bent into loops. Then circulate some ant-freeze through it and make a manifold in the water heater to transfer the heat to fresh water.
THEN, use a solar electric array to power the pump that pumps the anti-freeze around. Free heat.
There is more to it than that, but that's what I'd do.
You are too far north for it to be totally cost effective on the ROI. Tennessee is about the limit. Solar Hot Water heaters are great, if built correctly they will work well in your home. Just have a southern facing roof and you are good to go.
Solar HW, geothermal heat pump should move you to a 70% reduction in total generated energy consumed.
Have fun
rotard
HalfDork
1/11/12 11:15 p.m.
It might be cheaper to buy a new trailer to put in it's place.
Taiden
SuperDork
1/11/12 11:18 p.m.
http://www.instructables.com/id/Solar-Heater/
You can buy a Sharp 240W solar panel for $400. Inverter and wiring will add around $100 per panel.
This will generate around 1.3-1.5kWh/day, which will be 6 to 20 cents per day, or $20-$70 per year worth of power.
Consequently, payback is heavily dependent on local electric rates and tax rebates. With no rebate and cheap power, it'll take 25 years to pay back. With no rebate and expensive power, it'll take 7 years. This is why they've started going up in some large commercial installations as that's within some company's acceptable payback times, especially as it lowers their exposure to future rate increases. Rebates can be very generous in states with limited generating capacity and solar-friendly governments.
Solar hot water for heating pays back much, much faster. Its design is dependent on your location and site usage - but it would be a very rare site where you couldn't get a 5 year payback with a commercial system, and if you had a good collector location and installed it yourself it might pay for itself over one winter.
DrBoost
SuperDork
1/12/12 7:41 a.m.
Taiden wrote:
You will save more money, with less investment, and faster with solar water or home heating. Plus you can DIY the crap outta it. That's grassroots solar energy!
Yup. I'm doing my first solar heater this weekend.
JoeyM
SuperDork
1/12/12 7:51 a.m.
DrBoost wrote:
Taiden wrote:
You will save more money, with less investment, and faster with solar water or home heating. Plus you can DIY the crap outta it. That's grassroots solar energy!
Yup. I'm doing my first solar heater this weekend.
The law of thermodynamics likes this....you can loose a lot of energy turning light and heat into electricity to generate heat
You'll get the most bang for the buck with insulation as compared to solar. But yeah it is more difficult, walls have to be opened to do it right, etc. You mentioned it's drafty, so I'd start with easy stuff, like properly sealing around doors and windows. That will account for a surprisingly big chunk of the power bill right there.
Solar heat is a good backup but not necessarily a good single source heat system. Radiant solar systems integrated into a building are the most efficient but are also the most difficult to retrofit. In its simplest form, solar heat is just black painted or colored water tanks in an insulated box with a clear surface facing the sun. I can't find a pic now, but I saw one somewhere on teh web a while back that was a wood box with tubes made of that black PVC pipe. It was in the south facing wall of a free standing shop, during the day sunlight heated the black tubes and thus the water inside them. At night, the tubes radiated heat to the inside. Link to only one of zillions of DIY solar heat pages:
http://www.builditsolar.com/Projects/WaterHeating/water_heating.htm#1KSolarWater
If you can replace part of your electricity for heating with passive solar rather than trying to convert sunlight to electricity (big $$$ comparatively speaking), you have saved money.
Passive solar works in other ways as well. There was a house in Arizona? which had a gigantic stone fireplace inside, there were south facing windows in one wall. During the day, sunlight heated the stone fireplace and at night heavy insulated drapes were pulled across the windows. The fireplace then radiated warmth all night. If it was hot outside, the drapes could be pulled closed to cut off heat gain.
Don't confuse solar heat with solar electric.
Solar electric is expensive and produces very little juice. It requires batteries and converters, or no converter and expensive DC appliances.
Solar heat on the other hand, can be done for nearly free (passively), and can produce quite a bit. From beercan towers to garden hoses, strange looking windowboxes to big rocks. Google search "passive solar heat" and just start perusing.
In my Thermal Design class, we designed a small solar power plant (using off the self components) for a tiny fishing village in Alaska (in the southern bit). They had been using diesel generators and all expect in the dead of winter we could easily power the town with a 3 year payback. We also added a 4 position array to hold them in order to get better efficiency.
Taiden
SuperDork
1/12/12 8:38 a.m.
Also with the passive system I linked, if you were to close the outlet and open it up to the outside instead... During the summer it would draw air out of the house without adding any heat which would promote natural air flow through the house.
If you were to put this mechanism on some kind of electrically controlled solenoid or what not, you could hook it up to a thermostat
Having tinkered with home energy for about 35 years I can state that you must first control the energy that you use.
You will get a lot more bang for the buck with insulation, weatherstripping, smart use of natural light and controlled ventilation.
Photovoltaic cells are a minor part of my plan and include a cell for maintaining the batteries on the travel trailer, shop panel that charges my rechargeable tools batteries, tender for the riding mower and a small emergency light and one in the house that is used for charging the batteries used in remotes, flashlights, cell phones and laptops (sometimes).
In true GRM style, I bought the cells for $10 at a garage sale and got a bunch on uninterruptible power supplies for a Xerox place that was replacing equipment.
Being in Texas, heat is a minor problem for a couple of months.
Solar hot water experiments have been fun but expensive and labor intensive.
Works great until you get a girlfriend that has the habit of wanting the house at 60 degrees in the summer, then huddles on the couch under a blanket AND insists that in the winter the house must be hot enough to radiantly heat everything within 20 feet of the house (this includes her car).
If you make a 4 by 8 box out of ply wood like a mattress size /shape . This side is the face towards the sun out of a clear sliding glass door and in the bottom/back a 4 by 8 piece of black coroplast to absorbe heat . Then use a simple solar fan at one end pipe with a flex dryer vent line you should be able to generate significant hot air .
these guys pretty much covered it....
I lived in a solar house for a few months while I was on an Island in Panama... completely off the grid... rain water reclamation provided ALL of our water, solar provided all our electric... no heat, no a/c... we used fans sparingly where limited to times we could plug in our computers etc etc... and that was a $25,000 solar system... solar electric isn't practical...
however... those passive solar heat systems are super cheap and effective... if you want to go another notch further you can add a passive solar water heater... look around instructables and use some Google-fu and you'll find tons of DIY options...
when we eventually buy a house I intend on using at least some solar heat and solar water heater (I figure it could work very efficently... run though a tankless water heater to compensate for sunless days and it would be nice :)...
the best part about a trailer is you can retrofit all this kind of stuff with ease... not so easy if you have a cement foundation...
Hal
Dork
1/12/12 3:08 p.m.
Some years ago I helped a fellow teacher build a passive solar heating system for her house. The house was ideal for her setup. It was a split foyer house with the rear facing south. Ground level at the back was 1/2 way up the lower level.
She put in a 10' wide cement slab across the rear of the house with 3' high block walls. The part I helped with was installing a greenhouse kit she had purchased. It had an 8' high vertial wall on the long side and the roof sloped up to meet the house just above the tops of the windows.
She painted the slab and the walls black. She then got some pallet racking for free from a company remodeling their warehouse and a bunch of free black plastic 55 gallon drums from various sources. She put the drums on the pallet racking (3 rows high) and filled them with water.
Opening the windows on the lower and upper levels along with the open staircase in the front of the house allowed the air to circulate naturally. This heated all the rooms in the house except the spare bedroom located in the right front of the house. When she needed heat in that room she used a fan to push some in.
She kept good records and since the house was previously electrically heated she was able to recover her costs in 2 years. Her only costs were for the cement, blocks, and the greenhouse kit. All the labor she either did herself or had friends(like me) do.
I would reject solar in favor of a fusion reactor.